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Lab Safety manual

Food Science and Agricultural Chemistry


Exerpted from the Oklahoma State University Laboratory Safety Manual (http://www.pp.okstate.edu/ehs/HAZMAT/labman.htm)

June, 2005 Agricultural Chemistry Department




1.1 Chemical Spills 6

1.2 Biohazard Spills 11

1.3 Leaking Compressed Gas Cylinders 13

1.4 Fires 15

1.5 Medical Emergencies 16

1.6 Accident Reporting 18


2.1 General Safety and Operational Rules 20

2.2 General Safety Equipment 23

2.3 Personal Protective Equipment 30

2.4 Compressed Gas Safety 34

2.5 Safety Practices for Disposal of Broken Glassware 38

2.6 Centrifuge Safety 40

2.7 TREATED Biobiohazardous WASTE 42


3.1 Chemical Safety 44

3.2 Chemical Waste 53


4.1 Biological Safety Cabinets 60

4.2 Biohazard Waste 64


Appendix A Potential Peroxide-forming Chemicals 67

Appendix B INCOMPATIBLE Chemicals 68

Appendix C Potential Shock Sensitive Chemicals 70

Appendix D Neutralization of Spent Acids and Bases 72

Appendix E Cleaning Solution for Laboratory Glassware 77

Appendix F SAFETY Surveys – things to look for 78



ALL EMERGENCIES - Chemical, Medical, or Fire ...................... 7777

Chemical Spills and Waste Management ................................ 7736

Mr. Eby Noroozi (Res.) ......................................... (514) 457-1396

Laboratory Safety Manual Assistance .......................... 7921 / 7736

Dr. W.D. Marshall (Res.) ....................................... (514) 426-1746

Facilities Management Action Desk ........................................ 7154

Student Health Services ....................................................... 7992

Department Safety Committee Chair
Dr.Ashraf Ismail .................................................................. 7991

Macdonald Campus Safety Committee Chair
Dr. Robin Beech ...................................................................7535

Environmental Safety Office
Mr. Wayne Wood, Manager ................................................... 4563

University Fire Prevention Officer
Ms. Aline Fontaine ................................................................ 3664

Waste Management Program
Mr. Claude Lahaie, Manager .................................................. 5066

Radiation Safety Officer
Mr. Joseph Vincelli ............................................................... 1538

Biosafety and WHMIS Officer
Ms. Elizabeth St–Louis .......................................................... 1657

Poison Control Center ....................................... 1–800 – 463-5060

During the course of normal laboratory operations there is always the potential for an emergency to arise. These emergencies can be the result of a chemical spill, fire, or the need for medical assistance. In the event of an emergency, an emergency response plan should be implemented. This plan would include evacuation of the facility if such action is deemed appropriate. Internal communication is very important during any emergency situation. It is essential that all of us know how to act and react during the emergency. To accomplish this, it is necessary that a written Emergency Response Plan be developed and that all employees are trained and participate in drills. All accidents, regardless of severity, should be reported and investigated. Key elements of an emergency procedure plan are summarized by the acronym NEAR; Notify, Evacuate, Assemble, Report.


All chemical spills shall be reported in writing to Mr. E. Noroozi regardless of size. The report shall include the date, time, location, chemical(s) and their volume, and names of all persons involved, including any visitors who were exposed and personnel involved in the clean up.

A. Emergency Spills A chemical spill is classified as an Emergency Spill whenever it: 1. Causes personal injury or chemical exposure that requires medical attention; 2. Causes a fire hazard or uncontrollable volatility; 3. Requires a need for breathing apparatus of the supplied air or self-contained type to handle the material involved; 4. Involves or contaminates a public area; 5. Causes airborne contamination that requires local or building evacuation; 6. Causes a spill that cannot be controlled or isolated by laboratory personnel; 7. Causes damage to university property that will require repairs; 8. Involves any quantity of metallic mercury; 9. Cannot be properly handled due to lack of local trained personnel and/or equipment to perform a safe, effective cleanup; 10. Requires prolonged or overnight cleanup; 11. Involves an unknown substance; or 12. Enters the land or water.

Although the following tactics are prioritized in terms of usual preferred action sequences, each spill incident is unique and involves persons with varying levels of spill expertise and experience. Thus, for any individual incident, isolation of the spill and/or securing the area might best occur prior to or simultaneously with contacting campus security.

1. Contact the Campus Security for Assistance (7777). Notify the dispatcher of location of the spill and, if known, the chemical spilled. 2. Don't panic! Always send for help first, if possible. 3. If the spill presents an immediate danger, leave the spill site and warn others, control entry to the spill site, and wait for help. 4. Remove contaminated clothing. Flush skin/eyes with water at least 15 minutes to 30; use soap for intermediate and final cleaning of skin areas. 5. Protect yourself, then remove injured person(s) to fresh air, if safe to do so. 6. Notify nearby persons and evacuate as necessary. Prevent entry, as necessary, by posting a guard in a safe area and/or shutting doors. 7. If flammable vapors are involved, do not operate electrical switches unless to turn off motorized equipment. Try to turn off or remove heat sources, where safe to do so. 8. If the substance involved is an unknown, then emergency spill response procedures are limited to self-protection, notification of Campus Police at 7777 for response, isolation of the chemical, evacuating and securing the area involved. 9. Do not touch the spill without protective clothing. 10. Where the spill does not present immediate personal danger, try to control the spread or volume of the spill. This could mean shutting a door, moving nearby equipment to prevent further contamination, repositioning an overturned container or one that has a hole in the bottom or side, creating a dike by putting an absorbent around a spill or opening the sashes on the fume hoods to facilitate removal of vapors. 11. Never assume gases or vapors do not exist or are harmless because of lack of smell. 12. Increase ventilation by opening closed fume hood sashes to the 12 inch or full open position. Exterior doors may be opened to ventilate non-toxic vapors. 13. Use absorbents to collect substances. Reduce vapor concentrations by covering the surface of a liquid spill with absorbent. Control enlargement of the spill area by diking with absorbent.

B. Minor Spills Minor spills are those spills which do not fit the requirements for Emergency Spills. The following general procedures should be used for all minor spills: 1. Attend to any persons who may have been contaminated. If these persons require medical attention this is an Emergency Spill (See above). 2. Notify persons in the immediate area about the spill. 3. Evacuate all nonessential personnel from the spill area. 4. If the spilled material is flammable, turn off ignition and heat sources. 5. Avoid breathing vapors of the spilled material. If respiratory protection is necessary this is an Emergency Spill (See above). 6. Leave on or establish exhaust ventilation if it is safe to do so. 7. Secure supplies to effect cleanup. 8. Don appropriate personnel protective equipment. 9. Spilled Liquids a. Confine or contain the spill to a small area. Do not let it spread. b. For small quantities of inorganic acids or bases, use a neutralizing agent or an absorbent mixture (e.g., soda ash or diatomaceous earth). For small quantities of other materials, absorb the spill with a nonreactive material (such as vermiculite, clay, dry sand, or towels). c. For larger amounts of inorganic acids and bases, flush with large amounts of water (providing the water will not cause additional damage). Flooding is not recommended in storerooms where violent spattering may cause additional hazards or in areas where water-reactive chemicals may be present. d. Mop up the spill, wringing out the mop in a sink or a pail equipped with rollers. e. Carefully pick up and clean any cartons or bottles that have been splashed or immersed. f. If needed, vacuum the area with a HEPA filtered vacuum cleaner approved and designed for the material involved. g. If the spilled material is extremely volatile, let it evaporate and be exhausted by the laboratory hood (provided that the hood is authorized for use with the spilled chemical). 10. Spilled Solids Generally, sweep spilled solids of low toxicity into a dust pan and place them into a container suitable for that chemical. Additional precautions such as the use of a vacuum cleaner equipped with a HEPA filter may be necessary when cleaning up spills of more highly toxic solids. 11. Dispose of residues according to safe disposal procedures. Remembering that personal protective equipment, brooms, dust pans, and other items may require special disposal procedures. (See Section 3.4 - "Chemical Waste"). 12. Report the chemical spill in writing as required above.

C. Mercury Handling and Spill Clean Up 1. Health Effects A TLV of 0.05 mg/m3 has been established, based on an 8-hour day and 40-hour week. The TLV for mercury also carries a "skin" notation, which indicates that metallic mercury can be absorbed into the body as well as through inhalation and ingestion into the skin. Mercury vapors are odorless, colorless, and tasteless. A quantity as small as 1 milliliter can evaporate over time, as raise levels in excess of allowable limits. Mercury poisoning from exposure by chronic inhalation can cause emotional disturbances, unsteadiness, inflammation of the mouth and gums, general fatigue, memory loss, and headaches. In most cases of exposure by chronic inhalation, the symptoms of poisoning gradually disappear when the source of exposure is removed. Improvement, however, may be slow and complete recovery may take years. 2. Storage and Handling Because of the health effects of mercury, the extremely difficult and time-consuming procedures required to properly clean spills, every effort should be taken to prevent accidents involving mercury. Always store mercury in unbreakable containers and stored in a well-ventilated area. When breakage of instruments or apparatus containing mercury is a possibility, the equipment should be placed in an enameled or plastic tray or pan that can be cleaned easily and is large enough to contain the mercury. Transfers of mercury from one container to another should be carried out in a hood, over a tray or pan to confine any spills. If at all possible, the use of mercury thermometers should be avoided. If a mercury thermometer is required, many are now available with a Teflon® coating that will prevent shattering. Always wash hands after handling mercury to prevent skin absorption or irritation. 3. Air Monitoring Any mercury spill has the potential to generate airborne concentrations in excess of regulated levels. Large spills or spills with elevated vapor levels may dictate cleanup by a qualified contractor.

4. Protective Clothing For small spills, a laboratory coat, safety glasses, and gloves should be used. Gloves made of the following have been rated as excellent for protection against elemental mercury: Chlorinated polyethylene (CPE) Polyvinyl Chloride (PVC) Polyurethane Nitrile Rubber, (also known by Vito several brand names) Butyl Rubber Neoprene

If mercury has been spilled on the floor, the workers involved in cleanup and decontamination should wear plastic shoe covers. Campus Security should be called immediately if a spill is extensive enough to require workers to kneel or sit where mercury has been spilled since Tyvek® or similar impermeable clothing will be required. 5. Spill Kits Special spill kits are available downstairs from Mr. Noroozi. If a spill kit is purchased, follow the manufacturer's directions. Alternatively, a kit can be assembled with the following components: a. protective gloves, b. mercury suction pump or disposable pipettes to recover small droplets, c. elemental zinc powder (or commercial amalgam material), d. dilute sulfuric acid (5-10%) in spray bottle, e. sponge or tool to work amalgam, f. plastic trash bag, g. plastic container (for amalgam), and h. plastic sealed vial for recovered mercury. 6. Clean Up Procedures a. Wearing protective clothing, pools and droplets of metallic mercury can be pushed together and then collected by a suction pump. b. After the gross contamination has been removed, sprinkler the entire area with zinc powder. Spray the zinc with the dilute sulfuric acid. c. Using the sponge, work the zinc powder/sulfuric acid into a paste consistency while scrubbing the contaminated surface and cracks or crevices. d. To minimize contamination of housekeeping items, stiff paper may be used to assist in cleaning up the amalgam. e. After the paste has dried, it can be swept up and placed into the plastic container for disposal. f. Rags, shoe covers, sponges, and anything used for the cleanup should be placed in the trash bag to be disposed of as contaminated material. 7. Waste Disposal Contact EBY to arrange for removal of the mercury waste and contaminated items.

Biohazard Spills

A. Biological Spills Biological spills outside biological safety cabinets will generate aerosols that can be dispersed in the air throughout the laboratory. These spills can be very serious if they involve microorganisms that require Biosafety Level 3 containment, since most of these agents have the potential for transmitting disease by infectious aerosols. To reduce the risk of inhalation exposure in such an accident, occupants should leave the laboratory immediately. The laboratory should not be reentered to decontaminate or clean up the spill for at least 30 minutes. During this time the aerosol may be removed from the laboratory via the exhaust ventilation systems, such as biological safety cabinets or chemical fume hoods, if present. 1. Spills on the Body a. Remove contaminated clothing. b. Vigorously wash exposed area with soap and water for one minute. c. Obtain medical attention (if necessary). d. Report the incident to ÿour laboratory supervisor. 2. Biosafety Level 1 Organism Spill a. Wear disposable gloves. b. Soak paper towels in disinfectant and place over sill. c. Place towels in a plastic bag for disposal. d. Clean up spill area with fresh towels soaked in disinfectant. 3. Biosafety Level 2 Organism Spill a. Alert people in immediate area of spill. b. Put on protective equipment. This may include a laboratory coat with long sleeves, back-fastening gown or jumpsuit, disposable gloves, disposable shoe covers, safety goggles, mask or full-face shield. c. Cover spill with paper towels or other absorbent materials. d. Carefully pour a freshly prepared 1 to 10 dilution of household bleach around the edges of the spill and then into the spill. Avoid splashing. e. Allow a 20-minute contact period. f. After the spill has been absorbed, clean up the spill area with fresh towels soaked in disinfectant. g. Place towels in a plastic bag and decontaminate in an autoclave.

SECTION 1.3 - LEAKING COMPRESSED GAS CYLINDERS Occasionally, a cylinder or one of its component parts develops a leak. Most such leaks occur at the top of the cylinder in areas such as the valve threads, safety device, valve stem, and valve outlet. If a leak is suspected, do not use a flame for detection; rather, a flammable-gas leak detector or soapy water or other suitable "snoop" solution should be used. If the leak cannot be remedied by tightening a valve gland or a packing nut, emergency action procedures should be effected. Laboratory workers should never attempt to repair a leak at the valve threads or safety device; rather, they should consult with the supplier for instructions. If the substance in the compressed gas cylinder is not inert, or is hazardous, then use the procedures in Section 1.1 - "Chemical Spills". If the substance in the compressed gas cylinder is inert, or non-hazardous, contact the supplier for instructions.

SECTION 1.4 - FIRES Fires are a common emergency in the laboratory. In the event of a fire, do the following things: A. Assist any person in immediate danger to safety, if it can be accomplished without risk to yourself. B. Immediately activate the building fire alarm system. This will automatically notify the Campus Police, and sound the fire alarm bells or horns to evacuate the building. It is best to have these people respond and not to be needed than to have them arrive too late for potential rescue. C. If the fire is small enough, use a nearby fire extinguisher to control and extinguish the fire. Don't fight the fire if these conditions exist: a. The fire is too large or out of control. b. If the atmosphere is toxic. D. If the first attempts to put out the fire do not succeed, evacuate the building immediately. E. Doors, and if possible, windows, should be closed as the last person leaves a room or area of a lab. F. Do not use elevators; use building stairwells. G. When they hear the fire alarm sound, all personnel shall evacuate the building immediately. H. Upon evacuating the building, personnel should proceed at least 150 feet from the affected building. I. No personnel will be allowed to re-enter the building without permission of the Fire Department. J. You must report all fires to theEnvironmental Safety Office. All fires will be investigated by Environmental Health & Safety Officers and/or the local fire marshal.


Personal injury is not uncommon in laboratories. These injuries are usually minor cuts or burns but can be as severe as acute effects of chemical exposure or incidents such as heart attacks or strokes. The initial responsibility for first aid rests with the first person(s) at the scene, who should react quickly but in a calm and reassuring manner. The person assuming responsibility should immediately summon medical help (be explicit in reporting suspected types of injury or illness, location of victim, and type of assistance required). Send people to meet the ambulance crew at likely entrances of the building. The injured person should not be moved except where necessary to prevent further injury. The names of persons in your area trained in CPR and First Aid should be posted by your telephone. The number to call for medical emergencies (7777) shall also be posted by your telephone. All first aid, chemical exposures, and medical emergencies shall be reported as required in Section 1.7 - "Accident Reporting." Prevention of injuries should be a major emphasis of any laboratory safety program. Proper training will help prevent injuries from glassware, toxic chemicals, burns and electrical shock. In the event of any type of injury beyond that which first aid can treat, call 7777 for medical assistance. A. General 1. First aid is defined as any one-time treatment and any follow up visit for the purpose of observation, treatment of minor scratches, cuts, burns, splinters, and so forth, which do not ordinarily require medical care. 2. First aid equipment should be readily available in each laboratory. See Section 2.2-D, "First Aid Kits," for additional information. 3. Following any first aid, a nurse or physician qualified to handle chemical emergencies should provide further examination and treatment. The location and phone number of emergency services and the Oklahoma Poison Control Center (1-800-463-5060) should be clearly posted. 4. It is recommended that each laboratory have at least one person trained in basic first aid and cardiopulmonary resuscitation. 5. Someone knowledgeable about the accident should always accompany the injured person to the medical facility and a copy of any appropriate MSDS(s) should accompany the victim. 6. Minor injuries requiring first aid should always be reported to a supervisor and recorded on an Injury/Exposure Report Form (Workers' Compensation Form 2), which must be submitted to Personnel Services. Reasons for this are as follows. a. A minor injury may indicate a hazardous situation which should be corrected to prevent a serious future injury. b. It is important to document a minor injury as having been "work related" if the injury later leads to serious complications, such as from an infected cut. B. Personal Protection During First Aid 1. "Universal Precautions" are recommended when employees respond to emergencies which provide potential exposure to blood and other potentially infectious materials. "Universal Precautions" stress that all patients should be assumed to be infectious for HIV and other bloodborne pathogens. 2. Persons responding to a medical emergency should be protected from exposure to blood and other potentially infectious materials. Protection can be achieved through adherence to work practices designed to minimize or eliminate exposure and through the use of personal protective equipment (i.e., gloves, masks, and protective clothing), which provide a barrier between the worker and the exposure source. For most situations in which first aid is given, the following guidelines should be adequate. a. For bleeding control with minimal bleeding and for handling and cleaning instruments with microbial contamination, disposable gloves alone should be sufficient. b. For bleeding control with spurting blood, disposable gloves, a gown, a mask, and protective eye wear are recommended. c. For measuring temperature or measuring blood pressure, no protection is required. 3. After emergency care has been administered, hands and other skin surfaces should be washed immediately and thoroughly with warm water and soap if contaminated with blood, other body fluids to which universal precautions apply, or potentially contaminated articles. Hands should always be washed after gloves are removed, even if the gloves appear to be intact.


ALL injuries shall be reported to the laboratory supervisor and eventually to Environmental Safety personnel. Minor injuries many times are not reported because they are perceived to be embarrassing or that "careless actions" lead to the accident. However, minor injuries can sometimes lead to more serious complications that only become evident at a later time. Liability and insurance matters will be handled more effectively if initial accident documentation exists. In addition, all minor accidents should be investigated by safety and management personnel. Taking corrective action as a result of a minor accident may keep a major incident from happening. Without knowledge of all minor accidents, the desirable investigation is circumvented. An accident report form should be available in your First Aid Kit. Employees should understand that the purpose of reporting and documenting accidents is not to affix blame, but instead to determine the cause of the accident so that similar incidents may be prevented in the future. Worker's Compensation Forms document both the nature of the incident and also all injuries that resulted from the incident. If the accident involves overexposure to hazardous materials, an Employee Exposure Report shall also be prepared and forwarded to the Environmental Health & Safety Office.


People who work in scientific laboratories are exposed to many kinds of hazards. This can be said of most workplaces; in some, the hazards are well recognized (those of ordinary fire, for example) and the precautions to be taken are obvious. Laboratories, however, involve a greater variety of possible hazards than do most workplaces, and some of those hazards call for precautions not ordinary encountered elsewhere. Therefore, this manual has been provided to inform and guide the laboratory worker in safe practices which should help to avoid injury. This chapter sets forth those practices which are deemed good safety practices common to all laboratory operations.


A. General Rules of Safety 1. No running, jumping, or horseplay in laboratory areas shall be permitted. 2. No employee shall work alone in a laboratory or chemical storage area when performing a task that is considered unusually hazardous by the laboratory supervisor or safety officer. 3. Spills shall be cleaned immediately. Specifics of emergency spill tactics are provided in the Emergency Response chapter of this manual (Chapter 1.0). Water spills can create a hazard because of the slip potential and flooding of instruments (particularly on the floor below.) Small spills of liquids and solids on bench tops should be cleaned immediately to prevent contact with skin or clothing. 4. Lifting of heavy items must be performed in the proper fashion, using the legs to lift, and not the back. 5. It is the responsibility of everyone working in the laboratory to make certain that the laboratory is left clean after work is performed. 6. Children should be kept away from the workplace and areas of potentially high hazards. 7. Animals, except for those that are the subject of experimentation (approved by the Animal Experimentation Committee) are to be excluded from all University laboratory areas. B. Personal Hygiene 1. Wash promptly whenever a chemical has contacted the skin. Know what you are working with and have the necessary cleaning/neutralization material on hand and readily available. 2. No sandals, open toed shoes or clogs shall be worn by laboratory personnel. 3. Clothing worn in the laboratory should offer protection from splashes and spills, should be easily removable in case of accident, and should be at least fire resistant. Nonflammable, nonporous aprons offer the most satisfactory and the least expensive protection. Lab jackets or coats should have snap fasteners rather than buttons so that they can be readily removed. These coats are to be fastened closed while working and removed prior to exit from the laboratory. 4. Laboratory clothing should be kept clean and replaced when necessary. Clothing should be replaced or laundered using appropriate decontamination procedures whenever contamination is suspected. 5. Lab coats are not to be worn outside the laboratory, especially in rest room or break facilities. Any lab coats, respirators, or other protective gear must be left in the lab areas. Employees must, as a matter of routine, be responsible for washing, cleaning, and any other decontamination required when passing between the lab and the other areas. Washing should be done with soap and water; do not wash with solvents. 6. Inhalation is one of the four modes of entry for chemical exposure. "Sniff-testing" should not be done. 7. Never pipette by mouth. Always use a bulb to pipette. 8. Do not drink, eat, smoke, or apply cosmetics in the laboratory or chemical storage areas. 9. Do not use ice from laboratory ice machines for beverages. 10. No tobacco, or cosmetics products are permitted in the laboratory or chemical storage areas at any time. Cross contamination between these items and chemicals or samples is an obvious hazard and should be avoided. C. Housekeeping As in many general safety procedures, the following listing of good housekeeping practices indicate common sense activities which should be implemented as a matter of course in the laboratory. These recommendations are designed for accident prevention. 1. THE AREA MUST BE KEPT AS CLEAN AS THE WORK ALLOWS. 2. Each individual shall be responsible for maintaining the cleanliness of his/her area. 3. Reagents and equipment items should be returned to their proper place after use. This also applies to samples in progress. Contaminated or dirty glassware should be washed and not allowed to accumulate. 4. Chemicals, especially liquids, should never be stored on the floor, except in closed door cabinets suitable for the material to be stored. Nor should large bottles (2.5l or larger) be stored above the bench top. 5. Reagents, solutions, glassware, or other apparatus shall not be stored in hoods. Besides reducing the available work space, they may interfere with the proper air flow pattern and reduce the effectiveness of the hood as a safety device. 6. Counter tops should be kept neat and clean. Bench tops and fume hoods shall not be used for chemical storage. All work done in fume hoods shall be performed in the "Safety Zone", (6" minimum from the sash). 7. Stored items, equipment, and glass tubing shall not project beyond the front of shelf or counter limits. 8. Stored items or equipment shall not block access to the fire extinguisher(s), safety equipment, or other emergency items. 9. Stairways, hallways, passageways/aisles and access to emergency equipment and/or exits must be kept dry and not be obstructed in any fashion, including storage, equipment, phone or other wiring. 10. No combustible material such as paper, wooden boxes, pallets, etc., shall be stored under stairwells or in hallways. Hallways shall be kept free of boxes and materials so that exits or normal paths of travel will not be blocked 11. Materials stored near aisles shall be restrained to prevent their falling 12. All working surfaces and floors should be cleaned regularly. 13. All containers must be labeled with at least the identity of the contents and the hazards those chemicals present to users. If the contents of all containers are known we will no longer have an unknown waste disposal problem. D. Electrical The typical laboratory requires a large quantity of electrical power. This increases the likelihood of electrically-related problems and hazards. One must address both the electrical shock hazard to the facility occupants and the fire hazard potential. The following recommendations are basic to a sound electrical safety program in the laboratory. 1. All electrical equipment shall be properly grounded. 2. All electrical equipment shall be U.L. listed and/or F.M. approved. 3. Sufficient room for work must be present in the area of breaker boxes. All the circuit breakers and the fuses shall be labeled to indicate whether they are in the "on" or "off" position, and what appliance or room area is served.. Fuses must be properly rated 4. Equipment, appliance and extension cords shall be in good condition 5. Extension cords shall not be used as a substitute for permanent wiring 6. Electrical cords or other lines shall not be suspended unsupported across rooms or passageways. Do not route cords over metal objects such as emergency showers, overhead pipes or frames, metal racks, etc. Do not run cords through holes in walls or ceilings or through doorways or windows. Do not place under heavy objects. Do not place cords on pathways or other areas where repeated abuse can cause deterioration of insulation 7. Multi-outlet plugs shall not be used unless they have a built-in circuit breaker. This causes overloading on electrical wiring, which will cause damage and possible overheating. 8. Most of the portable multiple outlets are rated at 15 amps. Employees shall check when all connections are made to determine that the total input average will never exceed 15 amps. (The amperage on electrical equipment is usually stamped on the manufacturer's plate 9. All building electrical repairs, splices, and wiring shall be performed by the Physical Plant Electrical Department. 10. Electrical standards may be obtained by referencing Provincial / Municipal ELECTRICAL CODE E. Vacuum Operations In an evacuated system, the higher pressure is on the outside, rather than the inside, so that a break causes an implosion rather than an explosion. The resulting hazards consist of flying glass, spattered chemicals, and possibly fire. A moderate vacuum, such as 10 mm Hg, which can be achieved by a water aspirator, often seems safe compared with a high vacuum, such as 10-5 mm Hg. These numbers are deceptive, however, because the pressure differences between the outside and inside are comparable. Therefore any evacuated container must be regarded as an implosion hazard. 1. When working with a vacuum be aware of implosion hazards. Apply vacuum only to glassware specifically designed for this purpose, i.e., heavy wall filter flasks, desiccators, etc. 2. Never evacuate scratched, cracked, or etched glassware. Always check for stars or cracks before use. 3. Vacuum glassware which has been cooled to liquid nitrogen temperature or below should be annealed prior to reuse under vacuum. 4. Rotary evaporator condensers, receiving flasks, and traps should be taped or kept behind safety shields when under a vacuum. 5. All condensers connected to rotary evaporators should at least be cooled with circulating ice water. 6. The use of a vacuum for the distillation of the more volatile solvents, e.g. ether, low boiling petroleum ether and components, methylene chloride, etc., should be avoided whenever possible. In situations requiring reduced pressure, two alternatives should be considered; 1) Utilization of Rotovac System, or 2) Solvent recovery via atmospheric pressure distillation (preferred method). 7. Water, solvents, or corrosive gases should not be allowed to be drawn into a building vacuum system. 8. When a vacuum is supplied by a compressor or vacuum pump to distill volatile solvents, a cold trap should be used to contain solvent vapors. Cold traps should be of sufficient size and low enough temperature to collect all condensable vapors present in a vacuum system. If such a trap is not used, the pump or compression exhaust must be vented to the outside using explosion proof methods. 9. After completion of an operation in which a cold trap has been used, the system should be vented. This venting is important because volatile substances that have been collected in the trap may vaporize when the coolant has evaporated and cause a pressure buildup that could blow the apparatus apart. 10. After vacuum distillations, the pot residue must be cooled to room temperature before air is admitted to the apparatus. 11. All desiccators under vacuum should be completely enclosed in a shield or wrapped with friction tape in a grid pattern that leaves the contents visible and at the same time guards against flying glass should the vessel collapse. Various plastic (e.g., polycarbonate) desiccators now on the market reduce the implosion hazard and may be preferable. F. Handling Glassware 1. Glass breakage is a common cause of injuries in laboratories. Only glass in good condition should be used. 2. Discard or send for repair all broken, chipped, starred or badly scratched glassware. Hand protection should be used when picking up broken glass. For disposal of broken glass see Section 2.5 - "Safety Practices for Disposal of Broken Glassware". 3. Clean all glassware before sending for repair. 4. When using glass tubing all ends should be fire polished. Lubricate tubing with glycerin or water before inserting into rubber stoppers or rubber tubing. 5. Protect hands with leather gloves when inserting glass tubing. Hold elbows close to the body to limit movement when handling tubing. 6. Do not store glassware near the edge of shelves. Store large or heavier glassware on lower shelves. 7. Use glassware of the proper size. Allow at least 20% free space. Grasp a three-neck flask by the middle neck, not a side neck. 8. Do not attempt to catch glassware if it is dropped or knocked over. 9. Conventional laboratory glassware must never be pressurized.


Workers in a laboratory environment are surrounded by physical and chemical hazards, and the potential for accident and injury is always present. Adequate safety equipment in good working order shall be provided to prevent accidents and injury. A. Fire Extinguishers Facilities Management is responsible for the procurement, placement, inspection, and maintenance of all fire extinguishers on campus. 1. Laboratory personnel should be adequately trained regarding pertinent fire hazards associated with their work. 2. Fire extinguishers must be clearly labeled to indicate the types of fire they are designed to extinguish. The following codes as presented in NFPA 10 "Portable Fire Extinguishers" are: - Class A-fires in ordinary combustible materials such as wood, cloth, paper, rubber, and many plastics. - Class B-fires in flammable liquids, oils, greases, tars, oil-base paints, lacquers and flammable gases. - Class C-fires that involve energized electrical equipment where the electrical conductivity of the extinguishing medium is of importance; when electrical equipment is de-energized, extinguishers for class A or B fires may be safely used. - Class D-Fires of combustible metals such as magnesium, titanium, zirconium, sodium, lithium and potassium. 3. Fire extinguishers of the "Halon" type are specially designed so they leave no residue that could damage instruments or computers. (However, the area should be thoroughly ventilated before being reoccupied.) 4. Fire extinguishers should never be concealed from general view or blocked from access. 5. Facilities Management will install all fire extinguishers. Once a fire extinguisher has been installed, they will inspect and maintain the device. 6. If an employee notices a fire extinguisher discharged or not fully charged, an extinguisher with the safety pin pulled out, an extinguisher obstructed from view, or one not hanging in its proper location, please contact EBY at 7736. B. Safety Showers If all protective measures fail and an employee receives a chemical splash to their body, then safety showers have been provided throughout the laboratoratories for immediate and thorough washing of the body. 1. Personnel should familiarize themselves with the location of the nearest safety showers. 2. Employees should become familiar with the operation of the safety showers. 3. Safety showers are designed to flood the entire body in the event of a clothing fire or a major spill of a chemical. In either case, an employee should simply stand under the shower and activate the shower. Flood the affected area for a minimum of 15 to 30 minutes. 4. In the case of a corrosive liquid spill, the employee should remove the affected portion of clothing to reduce potential contact. Removal of clothing should be done while the individual is under the activated shower. 5. The laboratory supervisor should be notified as soon as possible if the employee required the use of the safety shower. 6. Safety showers should be tested annually to assure their proper operation. C. Eyewash Fountains If all protective measures fail and an employee receives a chemical splash to their eyes, then eye wash fountains have been provided throughout the laboratory complex for immediate and thorough washing of the eyes. 1. Personnel should familiarize themselves with the location and operation of the nearest eyewash fountains. 2. If the employee is wearing contact lenses: See Section 2.3.A-4. 3. Always flood the eyes for at least 15 minutes to be sure there is no residue of the corrosive liquid. Flush from the eye outward. 4. After thorough washing, the proper authorities should be notified and subsequent medical care for the employee should be seriously considered. This is because serious damage may have already occurred before the eye was thoroughly rinsed and/or the damage may not be immediately apparent. 5. Eyewash fountains should be tested weekly by laboratories for proper operation and to prevent the accumulation of bacteria. D. First Aid Kits 1. First aid kits, which should be located in conspicuous places (with location clearly marked) in the laboratory, are to be used for the immediate response to minor injuries, such as cuts or minor burns. All injury victims have the option of obtaining medical treatment or consultation. 2. Minor injuries requiring first aid shall always be reported to a supervisor: a. A minor injury may indicate a hazardous situation which should be corrected to prevent a more serious injury. b. It is important to document a minor injury as having been "work related" for the purpose of obtaining Worker's Compensation, should the injury lead to later, more serious, complications. 3. The location and phone number of emergency services and the Poison Control Center (1-800-463-5060) should be clearly posted. 4. A designated party should be responsible for monitoring and maintaining the first aid kit(s). There should be a log attached to the kit indicating the last inspection date and by whom the kit was inspected. 5. First aid kit contents should include items such as Band-aids®, sterile gauze pads, bandages, scissors, antiseptic wipes or ointments, and a first aid card. All kits should also contain examination gloves for response to emergencies in which blood is present. Pocket masks for CPR procedures are also recommended. 6. The following items are not recommended for use in a first-aid kit: a. Iodine - Tissue damage can be caused by improper use. b. Ice Pack Compress - If there is swelling of soft tissue, or other need for an ice pack, the person should be examined by a physician. c. Ammonia Inhalants - If an individual is unconscious, obtain help -- do not use ammonia. d. Tourniquet - Not required for minor injuries; use the pressure technique until medical assistance is available. 7. Laboratories where high-voltage equipment is in use should have access to an emergency electrical response board. This will contain an instruction card and a non-conductive stick to turn off the equipment and remove the shock victim from contact with the source 8. Laboratories using material for which the immediate administration of an antidote or neutralizing agent is manifested (such as hydrofluoric acid and calcium gluconate) should be considered. Additionally, these procedures should be included in the laboratory Chemical Hygiene Plan and have the appropriate special handling procedures outlined under the CHP as "Special Handling Procedures." E. Explosion-Proof Refrigerators If there is a need to refrigerate a substance that is flammable, it shall be refrigerated in an U.L. listed or F.M. approved explosion-proof refrigerator. This refrigerator is designed as such that any flammable vapors in the refrigerator do not contact sparks. This refrigerator must not be used for the storage of food F. Ventilation Hoods 1. Laboratory Hoods Work that involves hazards and noxious materials which are toxic, odoriferous, volatile or harmful shall be conducted within a laboratory hood. The primary purpose of a laboratory hood is to keep toxic or irritating vapors and fumes out of the general laboratory working area. A secondary purpose is to serve as a shield between the worker and equipment being used when there is the possibility of an explosive reaction. This is done by lowering the sash of the hood. a. Hood ventilation systems are best designed to have an airflow of not less than 60 ft/min (linear) and not more than 120 ft/min (linear) across the face of the hood. Flow rates of higher than 125 ft/min can cause turbulence problems and are not recommended. If possible, a mark will have been placed on the hood so the sash can be drawn to a point where 100 linear ft/min can be achieved. b. Avoid creation of strong cross drafts (100 fpm) caused by open doors and windows, air conditioning and/or heating vents, or personnel movement. Drafts will pull contaminants from the hood and into the laboratory. 100 FPM is generally not perceptible (100 fpm is approximately 3 mph, a normal walking pace). Air conditioning and heating vents and personnel traffic all create airflows in excess of 200 FPM, often much higher. Therefore, laboratory activity in the hood area should be minimized while the hood is in use. c. DO NOT ADJUST BAFFLES unless you have been instructed to do so. Do not remove baffles. If ventilation problems develop, contact Facilities Management Action Desk (7154) immediately. d. When not in use, the sash of the hood should be kept closed. While performing work in the hood, the sliding sash should be kept at the height designated to provide the minimum face velocity required (usually 100 lfm). This will ensure maximum velocity of air flow into the hood and out of the laboratory. e. Work should be performed as deeply within the fume hood as possible. Equipment, reagents, and glassware should be placed as far back in the hood as is practical without blocking the rear baffle. Solid objects placed at the face of the hood cause turbulence in the air flow. Therefore, each hood should have a clearly marked "safety zone" in which no work should be conducted or equipment placed. f. ONLY ITEMS NECESSARY TO PERFORM THE PRESENT EXPERIMENT SHOULD BE IN THE HOOD. The more equipment in the hood, the greater the air turbulence and the chance for gaseous escape into the lab g. When instrumentation is utilized for a process inside a hood, all instruments should be elevated a minimum of two inches from the hood base to facilitate proper air movement. h. The purpose and function of a hood is NOT to store chemicals or unused items. The fume hood is not a storage cabinet. i. Hoods shall not be used as a means of disposing of toxic or irritating chemicals, but only as a means of removing small quantities of vapor which might escape during laboratory operations. If vaporization of large quantities of such materials is a necessary part of the operation, a means of collecting the vapor by distillation or scrubbing should be considered, rather than allowing it to escape through the hood vent. The collected liquid can then be disposed of as a liquid waste. j. Some hoods are constructed of stainless steel. These are usually "perchloric acid hoods" or "radioisotope hoods." Never use perchloric acid in a hood not designed for that use. Perchloric acid hoods have a wash-down feature which should be used after each use of the hood and at least every two weeks when the hood is not in use. Date of wash-down should be recorded by the laboratory. k. Always look to assure fan motor power switch is in the "on" position before initiating experiment. Note: Some hoods do not have individual "on/off" switches and remain "on" continuously. l. Do not use infectious material in a chemical fume hood. m. Exhaust fans should be spark-proof if exhausting flammable vapors and corrosive resistant if handling corrosive fumes. n. Controls for all services (i.e., vacuum, gas, electric, water) should be located at the front of the hood and should be operable when the hood door is closed. o. Radioactive materials must not be used in the hoods without prior approval of the Radiation Safety Officer p. An emergency plan should be prepared in the event of ventilation failure or other unexpected occurrence such as fire or explosion in the hood.


2. Biological Safety Cabinets Biological Safety cabinets are among the most effective, as well as the most commonly used, primary containment devices in laboratories working with infectious agents. Class I and II biological safety cabinets, when used in conjunction with good microbiological techniques, provide an effective partial containment system for safe manipulation of moderate and some high-risk microorganisms. It is imperative that Class I and II biological safety cabinets are tested and certified in situs, any time the cabinet is moved, and at least annually thereafter. Certification at locations other than the final site may attest to the performance capability of the individual cabinet or model but does not supersede the critical certification prior to use in the laboratory. As with any other piece of laboratory equipment, personnel must be trained in the proper use of the biological safety cabinets. Of particular note are those activities which may disrupt the inward directional airflow through the work opening of Class I and II cabinets. Aerosol particles can escape the cabinet in various ways. Among these are repeated insertion and withdrawal of workers' arms in and from the work chamber, opening and closing doors to the laboratory or isolation cubicle, improper placement or operation of materials or equipment within the work chamber, or brisk walking past the cabinet while it is in use. Strict adherence to recommended practices for the use of biological safety cabinets is as important in attaining the maximum containment capability of the equipment as is the mechanical performance of the equipment itself. Always decontaminate the hood using procedures adopted by the laboratory after each use or at the end of the work day. BIOLOGICAL SAFETY CABINETS ARE NOT CHEMICAL FUME HOODS AND SHALL NOT BE USED AS SUCH.

3. Specialized Local Ventilation

Some instruments such as atomic absorption spectrophotometers (AA's or inductively coupled argon spectrometers (ICP's emit small quantities of hazardous materials during use. To prevent excessive accumulations of these materials, each of these instruments should be provided with an individual ventilation exhaust duct (as required by the manufacturer). Gas chromatography equipment using thermal conductivity detection should be kept in a hood or have a vent over the column outlets. G. Flammable-Liquid Storage Cabinets Cabinets designed for the storage of flammable liquids should be properly used and maintained. Read and follow the manufacturer's information and also follow these safety practices: a. Store only compatible materials inside a cabinet. b. Do not store paper or cardboard or other combustible packaging material in a flammable-liquid cabinet. c. The manufacturer establishes quantity limits for various sizes of flammable-liquid storage cabinets; do not overload a cabinet. NFPA Guidelines and OSHA Standards on Flammable Liquids are utilized as standards for Worker/Fire Protection In all laboratory work with flammable liquids the requirements should be consulted and followed. H. Safety Shields Safety shields should be used for protection against possible explosions, implosions or splash hazards. Laboratory equipment should be shielded on all sides so that there is no line-of-sight exposure of personnel. Provided its opening is covered by closed doors, the conventional laboratory exhaust hood is a readily available built-in shield. However, a portable shield should also be used when manipulations are performed, particularly with hoods that have vertical-rising doors rather than horizontal-sliding sashes. Portable shields can be used to protect against hazards of limited severity, e.g., small splashes, heat, and fires. A portable shield, however, provides no protection at the sides or back of the equipment and many such shields are not sufficiently weighted and may topple toward the worker when there is a blast (permitting exposure to flying objects). A fixed shield that completely surrounds the experimental apparatus can afford protection against minor blast damage. SECTION 2.3 - PERSONAL PROTECTIVE EQUIPMENT (PPE) * Employers must conduct a hazard assessment to determine if hazards present necessitate the use of PPE. * PPE selection must be made on the basis of hazard assessment and affected workers properly trained. * Defective or damaged PPE must not be used. A variety of laboratory personal protective equipment is commercially available and commonly used in laboratories. However, for the equipment to perform the desired function, it must be used and managed properly. Laboratory supervisors and/or departmental chemical hygiene officers shall determine a need for such equipment, monitor its effectiveness, train the employees, and monitor and enforce the proper use of such equipment. A. Eye Protection Eye protection is mandatory in all areas where there is potential for injury. This applies not only to persons who work continuously in these areas, but also to persons who may be in the area only temporarily, such as maintenance or clerical personnel. 1. The type of eye protection required depends on the hazard. For most situations, safety glasses with side shields are adequate. Where there is a danger of splashing chemicals, goggles are required. More hazardous operations include conducting reactions which have potential for explosion and using or mixing strong caustics or acids. In these situations, a face shield or a combination of face shield and safety goggles or glasses should be used 2. 2. Plastic safety glasses should be issued to employees who do not require corrective lenses. 3. For persons requiring corrective lenses, safety glasses ground to their prescription are available in a safety frame. Please note that the wearing of safety glasses does not excuse the employee from the requirement of wearing safety goggles 4. It is recommended that contact lenses not be permitted in the laboratory. The reasons for this prohibition are:Error! Bookmark not defined. a. If a corrosive liquid should splash in the eye, the natural reflex to clamp the eyelids shut makes it very difficult, if not impossible, to remove the contact lens before damage is done. b. The plastic used in contact lenses is permeable to some of the vapors found in the laboratory. These vapors can be trapped behind the lenses and can cause extensive irritation. c. The lenses can prevent tears from removing the irritant. If the Laboratory Supervisor chooses to allow contact lenses to be worn, they shall be protected by goggles designed specifically for use with contact lenses. (The protective goggles for use with contact lenses fit loosely around the eyes and have no vents for access by vapors.) If chemical vapors contact the eyes while wearing contact lenses, these steps should be followed: (1) Immediately remove the lenses. (2) Continuously flush the eyes, for at least 15 minutes. (3) Seek medical attention. 5. Although safety glasses are adequate protection for the majority of laboratory operations, they are not sufficient for certain specific operations where there is danger from splashes of corrosive liquids or flying particles. Examples are: washing glassware in chromic acid solution, grinding materials, or laboratory operations using glassware where there is significant hazard of explosion or breakage (i.e., in reduced or excess pressure or temperature). In such cases, goggles or face shields shall be worn if there is need for protection of the entire face and throat 6. If, despite all precautions, an employee should experience a splash of corrosive liquid in the eye, the employee is to proceed (with the assistance of a co-worker, if possible) to the nearest eyewash fountain and flush the eyes with water for at least 15 minutes. Flush from the eye outward. During this time, a co-worker should notify the proper authorities. 7. Visitors shall follow the same eye protection policy as employees. If they do not provide their own eye protection, it is the laboratory's responsibility to provide adequate protection. It should be the responsibility of the employee conducting the tour to enforce this policy. After use safety glasses/goggles used by visitors should be cleaned prior to reuse. B. Clothing The following guidelines for laboratory clothing are offered strictly from a safety standpoint. 1. Due to the potential for ignition, absorption, and entanglement in machinery, loose or torn clothing should be avoided unless wearing a lab coat 2. Dangling jewelry and excessively long hair pose the same type of safety hazard 3. Finger rings or other tight jewelry which is not easily removed should be avoided because of the danger of corrosive or irritating liquids getting underneath the piece and producing irritation 4. Lab coats should be provided for protection and convenience. They should be worn at all times in the lab areas. Due to the possible absorption and accumulation of chemicals in the material, lab coats should not be worn in the lunchroom or elsewhere outside the laboratory 5. Where infectious materials are present, closed (snapped) lab coats and gloves are essential. 6. Shoes shall be worn at all times in the laboratories. Sandals, open-toed shoes, and shoes with woven uppers, shall not be worn because of the danger of spillage of corrosive or irritating chemicals. 7. Care should be exercised in protective clothing selection; some protective clothing has very limited resistance to selected chemicals or fire. 8. Consult the MSDS for a chemical to find out the recommended clothing or PPE for a particular chemical. (Examples are latex, nitrile, or PVC gloves, or aprons.) C. Aprons - Rubber or Plastic Some operations in the laboratory, like washing glassware, require the handling of relatively large quantities of corrosive liquids in open containers. To protect clothing in such operations, plastic or rubber aprons may be supplied. A high-necked, calf- or ankle-length, rubberized laboratory apron or a long-sleeved, calf- or ankle-length, chemical- and fire-resistant laboratory coat should be worn anytime laboratory manipulation or experimentation is being conducted. Always wear long-sleeved and long-legged clothing; do not wear short-sleeved shirts, short trousers, or short skirts D. Gloves When handling chemicals, it is recommended that the correct gloves be used to protect the worker from accidental spills or contamination. If the gloves become contaminated they should be removed and discarded as soon as possible. There is no glove currently available that will protect a worker against all chemicals. Protection of the hands when working with solvents, detergents, or any hazardous material is essential in the defense of the body against contamination. Exposure of the hands to a potentially hazardous chemical could result in burns, chafing of the skin due to extraction of essential oils ("de-fatting"), or dermatitis. The skin could also become sensitized to the chemical and once sensitized, could react to lesser quantities of chemicals than otherwise would have any effect. It is well documented that primary skin irritations and sensitizations account for significantly greater numbers of lost time incidents on the job than any other single type of industrial injury. Proper selection of the glove material is essential to the performance of the glove as a barrier to chemicals. Several properties of both the glove material and the chemical with which it is to be used should influence the choice of the glove. Some of these properties include: permeability of the glove material, breakthrough time of the chemical, temperature of the chemical, thickness of the glove material, and the amount of the chemical that can be absorbed by the glove material (solubility effect). Glove materials vary widely in respect to these properties; for instance, neoprene is good for protection against most common oils, aliphatic hydrocarbons, and certain other solvents, but is unsatisfactory for use against aromatic hydrocarbons, halogenated hydrocarbons, ketones, and many other solvents. Gloves of various types are available and should be chosen for each specific job for compatibility and breakthrough characteristics. An excellent information is Guidelines for the Selection of Chemical Protective Clothing published by the American Conference of Governmental Industrial Hygienists (ACGIH) or information provided by glove manufacturers. 1. Selection For concentrated acids and alkalis, and organic solvents, natural rubber, neoprene or nitrile gloves are recommended. For handling hot objects, gloves made of heat-resistant materials (leather or Nomex) should be available and kept near the vicinity of ovens or muffle furnaces. A hot object should never be picked up with rubber or plastic gloves. Special insulated gloves should be worn when handling very cold objects such as liquid N2 or CO2. Do not use asbestos containing gloves. 2. Inspection Before each use, gloves should be inspected for discoloration, punctures, and tears. Rubber and plastic gloves may be checked by inflating with air and submersing them in water to check for air bubbles. 3. Usage Gloves should always be rinsed with a compatible solvent, soap and water prior to handling wash bottles or other laboratory fixtures. 4. Cleaning Before removal, gloves should be thoroughly washed, either with tap water or soap and water. 5. Removal Employees shall remove gloves before leaving the immediate work site to prevent contamination of door knobs, light switches, telephones, etc. When gloves are removed, pull the cuff over the hand. E. Respirators Respirator use should be avoided if at all possible (and is usually not required if adequate precautions are taken). Where possible, engineering controls (fume hoods, etc.) should be utilized to minimize exposure. If respirators are worn because OSHA Personal Exposure Limits (PELs) are being exceeded or other reasons, a respirator program must be established. The Environmental Safety Office should be consulted for additional information and guidance.


Many laboratory operations require the use of compressed gases for analytical or instrument operations. Compressed gases present a unique hazard. Depending on the particular gas, there is a potential for simultaneous exposure to both mechanical and chemical hazards. Gases may be combustible, explosive, corrosive, poisonous, inert, or a combination of hazards. If the gas is flammable, flash points lower than room temperature compounded by high rates of diffusion (which allow for fast permeation throughout the laboratory) present a danger of fire or explosion. Additional hazards of reactivity and toxicity of the gas, as well as asphyxiation, can be caused by high concentrations of even "harmless" gases such as nitrogen. Since the gases are contained in heavy, highly pressurized metal containers, the large amount of potential energy resulting from compression of the gas makes the cylinder a potential rocket or fragmentation bomb. In summary, careful procedures are necessary for handling the various compressed gases, the cylinders containing the compressed gases, regulators or valves used to control gas glow, and the piping used to confine gases during flow. A. Identification 1. The contents of any compressed gas cylinder shall be clearly identified for easy, quick, and complete determination by any laboratory worker. Such identification should be stenciled or stamped on the cylinder or a label, provided that it cannot be removed from the cylinder. Commercially available three-part tag systems can be very useful for identification and inventory. No compressed gas cylinder shall be accepted for use that does not legibly identify its contents by name. Color coding is not a reliable means of identification; cylinder colors vary with the supplier, and labels on caps have little value as caps are interchangeable. If the labeling on a cylinder becomes unclear or an attached tag is defaced to the point the contents cannot be identified, the cylinder should be marked "contents unknown" and returned directly to the manufacturer. 2. All gas lines leading from a compressed gas supply should be clearly labeled to identify the gas, the laboratory served, and the relevant emergency telephone numbers. The labels should be color coded to distinguish hazardous gases (such as flammable, toxic, or corrosive substances) (e.g., a yellow background and black letters). Signs should be conspicuously posted in areas where flammable compressed gases are stored, identifying the substances and appropriate precautions (e.g., HYDROGEN - FLAMMABLE GAS - NO SMOKING - NO OPEN FLAMES). B. Handling and Use 1. Since gas cylinders are tall and narrow, they shall be secured at all times to prevent tipping . Cylinders may be attached to a bench top, individually to the wall, placed in a holding cage, or have a non-tip base attached 2. When new cylinders are received, they should be inspected. During this inspection, one should insure the proper cap is securely in place and the cylinder is not leaking. Cylinders shall have clear labels indicating the type of gas contained. If the cylinders are acceptable, they shall be stored in a proper location. If a leaking cylinder is discovered, move it to a safe place (if it is safe to do so) and inform Environmental Health Services. You should also call the vendor as soon as possible. Under no circumstances should any attempt be made to repair a cylinder or valve. 3. Cylinders containing flammable gases such as hydrogen or acetylene shall not be stored in close proximity to open flames, areas where electrical sparks are generated, or where other sources of ignition may be present. Cylinders containing acetylene shall never be stored on their side. An open flame shall never be used to detect leaks of flammable gases. Hydrogen flame is invisible, so "feel" for heat. All cylinders containing flammable gases should be stored in a well-ventilated area. 4. Oxygen cylinders, full or empty, shall not be stored in the same vicinity as flammable gases. The proper storage for oxygen cylinders requires that a minimum of 50 feet be maintained between flammable gas cylinders and oxygen cylinders or the storage areas be separated, at a minimum, by a fire wall five feet high with a fire rating of 0.5 hours. Greasy and oily materials shall never be stored around oxygen; nor should oil or grease be applied to fittings. 5. Standard cylinder-valve outlet connections have been devised by the Compressed Gas Association (CGA) to prevent mixing of incompatible gases. The outlet threads used vary in diameter; some are internal, some are external; some are right-handed, some are left-handed. In general, right-handed threads are used for non-fuel and water-pumped gases, while left-handed threads are used for fuel and oil-pump gases. To minimize undesirable connections, only CGA standard combinations of valves and fittings should be used in compressed gas installations; the assembly of miscellaneous parts should be avoided. The threads on cylinder valves, regulators and other fittings should be examined to ensure they correspond and are undamaged. The catalogs from Matheson or Air Products are a good source of information. Cylinders should be placed with the valve accessible at all times. The main cylinder valve should be closed as soon as it is no longer necessary that it be open (i.e., it should never be left open when the equipment is unattended or not operating). This is necessary not only for safety when the cylinder is under pressure, but also to prevent the corrosion and contamination resulting from diffusion of air and moisture into the cylinder after it has been emptied. Cylinders are equipped with either a hand wheel or stem valve. For cylinders equipped with a stem valve, the valve spindle key should remain on the stem while the cylinder is in service. Only wrenches or tools provided by the cylinder supplier should be used to open or close a valve. At no time should pliers be used to open a cylinder valve. Some valves may require washers; this should be checked before the regulator is fitted. Cylinder valves should be opened slowly. Main cylinder valves should never be opened all the way. When opening the valve on a cylinder containing an irritating or toxic gas, the user should position the cylinder with the valve pointing away from them and warn those working nearby. 6. Regulators are gas specific and not necessarily interchangeable. Always make sure that the regulator and valve fittings are compatible. If there is any question as to the suitability of a regulator for a particular gas, check with your vendor for advice. After the regulator is attached, the cylinder valve should be opened just enough to indicate pressure on the regulator gauge (no more than one full turn) and all the connections checked with a soap solution for leaks. Never use oil or grease on the regulator of a cylinder valve. 7. Piping material shall be compatible with the gas being supplied. Copper piping shall not be used for acetylene, nor plastic piping for any portion of a high pressure system. Do not use cast iron pipe for chlorine; do not conceal distribution lines where a high concentration of a leaking hazardous gas can build up and cause an accident. Distribution lines and their outlets should be clearly labeled as to the type of gas contained. Piping systems should be inspected for leaks on a regular basis. Special attention should be given to fittings as well as possible cracks that may have developed. 8. A cylinder should never be emptied to a pressure lower than 172 kPa (25 psi/in2) (the residual contents may become contaminated if the valve is left open). When work involving a compressed gas is completed, the cylinder must be turned off, and if possible, the lines bled. When the cylinder needs to be removed or is empty (see above), all valves shall be closed, the system bled, and the regulator removed. The valve cap shall be replaced, the cylinder clearly marked as "empty," and returned to a storage area for pickup by the supplier. Empty and full cylinders should be stored in separate areas. 9. Where the possibility of flow reversal exists, the cylinder discharge lines should be equipped with approved check valves to prevent inadvertent contamination of cylinders connected to a closed system. "Sucking back" is particularly troublesome where gases are used as reactants in a closed system. A cylinder in such a system should be shut off and removed from the system when the pressure remaining in the cylinder is at least 172 kPa (25 psi/in2). If there is a possibility that the container has been contaminated, it should be so labeled and returned to the supplier. 10. Liquid bulk cylinders may be used in laboratories where a high volume of gas is needed. These cylinders usually have a number of valves on the top of the cylinder. All valves should be clearly marked as to their function. These cylinders will also vent their contents when a preset internal pressure is reached, therefore, they should be stored or placed in service where there is adequate ventilation. If a liquid fraction is removed from a cylinder, proper hand and eye protection must be worn and the liquid collected in a Dewar flask. 11. Always use safety glasses (preferably a face shield) when handling and using compressed gases, especially when connecting and disconnecting compressed gas regulators and lines. 12. All compressed gas cylinders, including lecture-size cylinders, shall be returned to the supplier when empty or no longer in use. C. Transportation of Cylinders The cylinders that contain compressed gases are primarily shipping containers and should not be subjected to rough handling or abuse. Such misuse can seriously weaken the cylinder and render it unfit for further use or transform it into a rocket having sufficient thrust to drive it through masonry walls. 1. To protect the valve during transportation, the cover cap should be screwed on hand tight and remain on until the cylinder is in place and ready for use. 2. Cylinders should never be rolled or dragged. 3. When moving large cylinders, they should be strapped to a properly designed wheeled cart to ensure stability. 4. Only one cylinder should be handled (moved) at a time. D. Cryogenic Liquids A number of hazards may be present from the use of cryogenic liquids in the laboratory. Employees should be properly trained in these hazards prior to use. The transfer of liquefied gases from one container to another should not be attempted for the first time without the direct supervision and instruction of someone experienced in the operation. 1. Fire/Explosions a. Neither liquid nitrogen nor liquid air should be used to cool a flammable mixture in the presence of air because oxygen can condense from the air and lead to a potentially explosive condition. b. Adequate ventilation must always be used to prevent the build-up of vapors of flammable gases such as hydrogen, methane, and acetylene. c. Adequate ventilation is also required when using gases such as nitrogen, helium, or hydrogen. In these cases, oxygen can be condensed out of the atmosphere creating a potential for explosive conditions. 2. Pressure Cylinders and other pressure vessels used for the storage and handling of liquefied gases should not be filled to more than 80% of capacity, to prevent the possibility of thermal expansion and the resulting bursting of the vessel by hydrostatic pressure. 3. Embrittlement of Structural Materials Appropriate impact-resistant containers must be used that have been designed to withstand the extremely low temperatures. 4. Contact With and Destruction of Living Tissue Even very brief contact with a cryogenic liquid is capable of causing tissue damage similar to that of thermal burns. Prolonged contact may result in blood clots that have potentially serious consequences. In addition, surfaces cooled by cryogenic liquids can cause severe damage to the skin. Gloves and eye protection (preferably a face shield) should be worn at all times when handling cryogenic liquids. Gloves should be chosen that are impervious to the fluid being handled and loose enough to be tossed off easily. Appropriate dry gloves should be used when handling dry ice. "Chunks" or cubes should be added slowly to any liquid portion of the cooling bath to avoid foaming over. 5. Asphyxiation As the liquid form of gases warm and become airborne, oxygen may be displaced to the point that employees may experience oxygen deficiency or asphyxiation. Any area where such materials are used should be well ventilated. For this same reason, employees should avoid lowering their heads into a dry ice chest. (Carbon dioxide is heavier than air, and suffocation can result.)


Inspect all glassware before use. Do not use broken, chipped, starred or badly scratched glassware. If it cannot be repaired, discard it in containers specifically designated for broken glass. All broken glass requires special handling and disposal procedures to prevent injury not only to lab personnel, but members of the janitorial staff as well. All broken glass shall be disposed in rigid, puncture proof containers such as a cardboard box with taped seams, or a plastic bucket or metal can with a sealing lid. All broken glass disposal containers shall be clearly marked "DANGER - BROKEN GLASS" Limit quantities to no more than approximately 15 to 20 pounds so that lifting of the container will not create a situation that could cause back injury. 1. Food, beverage, and uncontaminated glassware: Dispose in a rigid, puncture proof container such as a box with sealed or taped edges or a metal or thick plastic can or bucket with a sealing lid. Label container "DANGER - BROKEN GLASS 2. Glassware with biological contamination: Glassware that has been in contact with infectious agents may include: used slides, cover slips, test tubes, beakers, pipettes, etc. Contaminated glassware shall be disinfected before disposal. Dispose in a rigid, puncture proof container such as a box with sealed or taped edges or a metal or thick plastic can or bucket with a sealing lid. Label container "DANGER - BROKEN GLASS". Contact EBY if you require further information. 3. Glassware with chemical contamination: Empty the contents of the glassware into a suitable container if safe to do so. (See Section 3.4 - "Chemical Waste" for disposal procedures.)


Does your lab have a centrifuge? Have you been instructed in proper use of this valuable tool? Are you aware that 90% of centrifuge failures are the result of user errors? These errors may result in lost samples and damaged equipment as well as a risk to you the lab user and your lab. This partial checklist is submitted for your convenience and, if appropriate, should be included in your lab's Chemical Hygiene Plan, possibly in the Special Procedures section. Protocol calls for centrifugation. The following are suggested steps. (First review the owner's manual--if manual not available, obtain a copy before proceeding.) 1. Which centrifuge 2. Which rotor 3. Correct tube size and adapter 4. What speed & length of time After the above selections have been made, and the owner's manual and centrifuge log consulted (especially critical on ultra centrifuge), insure the tube fits properly in the rotor. This is important because up to 600,000 G forces may be generated during the centrifugation procedure. Insure you are using the appropriate level of containment. Is the material potentially infectious/radioactive? If so, are you using aerosol containment tubes? Are you loading and unloading the rotor in a biological safety cabinet? Suggested steps to follow BEFORE starting the centrifuge: 1. Insure centrifuge bowl and tubes are dry. 2. Is the centrifuge spindle clean? 3. Avoid overfilling of tubes and bottles 4. Insure rotor is properly seated on drive hub. 5. Make sure tubes are properly balanced in rotor (½ gram at 1 G is roughly equivalent to 250 Kg @ 500,000 G's). 6. Are O-rings properly attached to the rotor? Is the vacuum grease fresh? 7. Has the rotor been properly secured to drive? 8. Is the centrifuge lid shut properly? After the above steps are taken and the centrifuge has started, make sure the run is proceeding normally before you leave the area. Once the centrifuge run is complete, make sure the rotor has STOPPED completely before you open the centrifuge lid; then check for spills. If infectious material was placed in the centrifuge, WAIT 10 minutes before opening the centrifuge lid. If leak or damage has occurred, close the lid and plan proper decontamination and cleanup. For biological spills, contact the Biological Safety Officer. Maintenance/Cleaning: 1. Keep rotors clean and dry. If spills occur, make sure rotor has been cleaned/decontaminated. If salts or corrosive materials were used, ensure they have been removed form the rotor. 2. Avoid mechanical scratches. The smallest, scarcely visible scratch allows etching to enlarge the fracture, which is subject to enormous rupturing forces at high G's--a vicious cycle leading to rotor explosion. 3. Avoid bottle brushes with sharp metal ends and harsh detergents when cleaning aluminum rotor heads. 4. After proper clean-up, rinse the rotor with de-ionized water. Inspections: 1. Check the rotor for rough spots, pitting, and discoloration. If discovered, check with the manufacturer before using. Use professional rotor inspection services frequently. These visits can be arranged to accommodate numerous users throughout the University. 2. Consult the centrifuge manufacturer and centrifuge log for the derating schedule for the rotor. Remember--an unlogged ultra-speed centrifuge is a ticking time bomb.


The following procedure for handling Treated Biohazardous Wastes generated in campus labs was developed from "Solid Waste Management Regulations". Definitions: The following words and terms, when used in this subchapter, shall have the following meaning, unless the context clearly indicates otherwise: "Treated biohazardous wastes" means any bio-waste that has been treated by one of the folloiwng methods and rendered harmless and biologically inert: 1. Incineration in an approved incinerator; 2. Steam sterilization at sufficient temperature and for sufficient time to destory infectious agents in waste; 3. Chemical disinfection where contact tiem, concentration and quantity of the chemical disinfectant are sufficient to destroy infectious agents in waste; 4. Any other treatment methods approved by McGill and generally recognized as effective. Note that incineration in an approved incinerator is the preferred mehtod of treatment. The only acceptable treatment for antineoplastics and cytotoxic drugs is incineration in a specially designed on-site incinerator, a commercial biomedical waste processing facility, or a facility permitted to dispose of waste. Material generated at within our lab facilities that meet definitions of "Treated Bio-waste SHALL be disposed of as municipal solid waste ONLY after it has met decontamination conditions of. In addition to the above requirements, the following label shall be affixed to two sides of the "Yellow Bag"... Material contained in this bag meets the definition of "Treated Biological Wastes" and has undergone steam sterilizaiton or chemical disinfection, effectively rendering any waste harmless and biologically inert. I further certify by placing this label on a container that no sharps, glass or needles that might puncture the bag are contained within. Date: After affixing the above label, the waste should be double-bagged in dark (opaque) trash bags and may be placed in a solid-waste container.


The development of a detailed chemical hygiene plan is necessary to establish continuity, to train personnel and to help ensure that all employees recognize and comply with work place safety. It is extremely difficult to effectively communicate and enforce requirements without a detailed chemical hygiene plan. An effective chemical hygiene plan necessitates that mechanisms be in place and functioning to ensure that safety policies and procedures are being adhered to, personnel are meeting their safety responsibilities, and an effective form of monitoring and documentation is in place for confirmation purposes. The basic Laboratory Safety Manual is intended to serve primarily as a general safety document for compliance with various environmental and occupational health and safety rules and regulations. The development of a detailed chemical hygiene plan and the implementation of this plan within employee training programs should result in a safer working environment for us all. SECTION 3.1 - CHEMICAL SAFETY Some definitions are helpful. Action level - A concentration for a specific substance, calculated as an eight (8) hour time-weighted average, which initiates certain required activities such as exposure monitoring and medical surveillance. Typically it is one-half that of the PEL for that substance. Acute - Severe, often dangerous conditions in which relatively rapid changes occur. Carcinogen - Any substance that causes the development of cancerous growths in living tissue, either those that are known to induce cancer in man or animals or experimental carcinogens that have been found to cause cancer in animals under experimental conditions. Designated Area - An area which may be used for work with "select carcinogens, reproductive toxins, or substances which have a high degree of acute toxicity." A designated area may be the entire laboratory, an area of a laboratory, or a device such as a laboratory hood. A designated area shall be placarded to reflect the designated hazard. Employee - An individual employed in a laboratory work place who may be exposed to hazardous materials in the course of his or her assignments. Health Hazard - A substance for which there is statistically significant evidence based on at least one study conducted in accordance with established scientific principles that acute or chronic health effects may occur in exposed employees. This term includes carcinogens, toxic agents, reproductive toxins, irritants, corrosives, sensitizers, hepatotoxins, nephrotoxins, neurotoxins, agents which act on the hematopoietic systems, and agents which damage the lungs, skin, eyes, or mucous membranes. MSDS - Material Safety Data Sheet. (PEL) Permissible Exposure Limit - An exposure limit that is published and enforced by OSHA as a legal standard. PEL may be either a time-weighted-average (TWA) exposure limit (8 hour), a 15-minute short term exposure limit (STEL), or a ceiling (C). The PELs are found in Tables Z-1, Z-2, or Z-3 of 29 CFR 1910.100. This level of exposure is deemed to be the maximum safe concentration and is generally the same value as the threshold limit value (TLV). (PPE) Personal Protective Equipment - Any devices or clothing worn by the worker to protect against hazards in the environment. Examples are respirators, gloves, and chemical splash goggles. Respirator - A device which is designed to protect the wearer from inhaling harmful contaminants. (STEL) Short Term Exposure Limit - Represented as STEL or TLV-STEL, this is the maximum concentration to which workers can be exposed for a short period of time (15 minutes) for only four times throughout the day with at least one hour between exposures. (TLV) Threshold Limit Value - Airborne concentrations of substances devised by the ACGIH that represents conditions under which it is believed that nearly all workers may be exposed day after day with no adverse effect. TLVs are advisory exposure guidelines, not legal standards, that are based on evidence from industrial experience, animal studies, or human studies when they exist. There are three different types of TLVs: Time Weighted Average (TLV-TWA), Short Term Exposure Limit (TLV-STEL) and Ceiling (TLV-C). (See also PEL.) Time Weighted Average - (TLV-TWA, Threshold Limit Value-Time Weighted Average) The time weighted average airborne chemical concentration for a normal eight hour work day and a 40 hour work week to which nearly all workers may be repeatedly exposed, day after day, without adverse effect. Toxic - Substances such as carcinogens, irritants, or poisonous gases, liquids, and solids which are irritating to or affect the health of humans. Working with potentially hazardous chemicals is an everyday occurrence in a laboratory setting. Hazardous situations can occur if employees are not educated in general chemical safety, toxicological information, and procedures for handling and storage for the chemicals they are using. This section of the laboratory manual addresses these educational components and spells out specific protocols to minimize hazardous chemical exposures. A. Modes of Entry There are four major modes of entry to chemicals: inhalation, skin absorption, injection, and ingestion. Inhalation and skin absorption are the predominant occupational exposures you may expect to encounter in the laboratory and will be discussed in some detail. Accidental injection of chemicals can be eliminated by good laboratory safety practices. Accidental ingestion of chemicals can be eliminated by a combination of good laboratory and hygienic practices such as washing hands and prohibiting foods, drinks, cosmetics, and tobacco products in the laboratory workplace (see Section 2.1 - "General Safety and Operational Rules"). All potential exposures, i.e., inhalation, skin absorption, injection, and ingestion, are discussed in the Material Safety Data Sheets available for each chemical or product. The hundreds of chemicals which employees are routinely exposed to during the course of their work in the laboratory can be divided into three main types: volatile solvents, corrosives, and toxic solids. The particular hazards associated with exposure to these materials, and ways to avoid them, are discussed in detail below. B. Basic Chemical Classifications 1. Volatile Solvents Organic solvents are perhaps the most ubiquitous chemicals found in the laboratory setting. The potential chronic health effects of some of these materials warrant special attention as one is likely to be exposed to more solvents than any other type of chemical. For safety purposes, these chemicals are generally subdivided into two categories: chlorinated and non-chlorinated. This is done mainly because the chlorinated solvents are, in general, not flammable while non-chlorinated solvents are often flammable. It should be kept in mind, however, that the chlorinated solvents do decompose when burned. This results in high concentrations of toxic vapors, such as phosgene and hydrogen chloride. Keeping in mind the difference in flammability between these two classes of solvents, we can discuss the health effects common to both classes. The primary route of exposure to these materials is through inhalation. In general, high concentrations of the vapor, when inhaled, produce drowsiness, dizziness and headaches. This can occur quite quickly, since chemical vapors are rapidly absorbed. Most of the solvents will also act as upper respiratory and/or eye irritants. One physical property common to most solvents is odor. Unfortunately, the odor of a solvent offers little in the way of determining whether or not the environment is immediately hazardous. Solvent odor thresholds vary widely and acclimation or odor fatigue is often rapid. Odor is also not generally indicative of the degree of hazard that the material presents. Butyl mercaptan has such an extremely disagreeable odor that one cannot tolerate a concentration necessary to be injurious. Chloroform, however, has a sweet odor to many people and tolerance levels can far exceed safe levels. Chronic effects of solvent exposure vary widely. Of most concern is the potential for lung, liver, and kidney damage posed by some solvents. This, in general, applies to solvents which are not water soluble. Examples of these solvents would be benzene, toluene, xylene, chloroform, carbon tetrachloride, and trichloroethylene. Instances of chronic disease caused by occupational exposure to these solvents have been documented. However, it must be kept in mind that everyone reacts differently and individual susceptibilities are quite variable. Skin absorption is an additional mode of entry for which an exposure to a solvent may occur. Most commonly, solvents act to de-fat the skin. This will cause drying and cracking of the skin, and may lead to chronic dermatitis with prolonged and repeated exposure. Some solvents can also act as corrosives. Most amines and phenols act in this manner. In addition, many of the solvents (dimethyl sulfoxide and dimethyl formamide, for example) will penetrate the skin and be absorbed into the body. In this case, the effects of exposure will be analogous to inhalation exposure. Carbon disulfide, n-butyl alcohol, and phenol are common solvents which can penetrate intact skin. For those solvents, there will be a notation of skin exposure noted on the Material Safety Data Sheet. Most skin contact with solvents can be avoided by wearing gloves suitable for that chemical. It is important that the glove be resistant to the material being handled. Using the wrong glove can give a false sense of security and overexposure via the skin may result. If a solvent penetrates the glove, a prolonged contact will result due to slowed evaporation rates. Rubber and neoprene gloves can be classed as good general purpose gloves, but a chemical resistance chart and the MSDS should always be consulted (See also Section 2.3 - "Personal Protective Equipment"). Direct liquid contact by solvents in the eyes can be very serious. The victim could easily panic. Get them to the eye wash immediately and flush the eyes for at least 15 to 30 minutes. Medical assistance should also be summoned. In summary, volatile solvents can pose inhalation, skin, and ingestion hazards. Some of the solvents may also be flammable, which could cause fire and/or explosion hazards. Whenever possible, use volatile solvents in a properly operating fume hood to eliminate inhalation hazards, use correct skin and eye protection and use good laboratory and hygienic technique to eliminate any possible ingestion of volatile solvents. 2. Acid and Bases Common to all acids and bases is their corrosive action on human tissues. Minor exposures are generally reversible, although often painful for a short period of time. The reversibility of the effects of acid or base exposure will depend on three factors: the duration of exposure, concentration of the material, and the first aid methods used. Exposure can occur through skin absorption or inhalation. With inhalation exposure, remove the victim from the area (try to keep the victim from breathing too deeply, as this may exacerbate the effects) and summon medical help. Skin contact is the most common route of exposure. Here the concentration and type of acid are the most important factors. In concentrated forms, all types of corrosives may cause severe penetrating burns. Dilute solutions do not have the same warning properties as concentrated forms, so guard against exposure. One should be particularly careful with hydrofluoric acid (see Section 2.2-3). Neoprene gloves provide the best protection from skin exposure to both acids and bases, but in all cases, follow the recommendations in the MSDS. When using or dispensing concentrated acids or bases, a lab coat or apron and a full face shield is required (see Section 2.3 - "Personal Protective Equipment"). If there is skin or eye contact with acids or bases, make sure to flush the area with water for 15 to 30 minutes and summon medical assistance. 3. Toxic Solids Many of the chemicals used in the laboratory that are solid and toxic are used in solution, so skin absorption can be of a concern. This is particularly true when a substance is dissolved in a solvent which can penetrate the skin. Also, an oxidizing material dissolved in water can act directly on the skin causing irritation where the solid alone would be relatively less irritating. It is therefore important that proper personal protective equipment be worn (See Section 2.3 - "Personal Protective Equipment"). In the solid form, the greatest risk of exposure is through inhalation. This risk can be lessened by wearing the appropriate respirator and/or working in a fume hood. C. Incompatible Chemicals Certain hazardous chemicals cannot be mixed or stored safely with other chemicals due to potentially severe or extremely toxic reactions taking place. For example, keep oxidizing agents separated from reducing agents, initiators separated from monomers, and acids separated from alkalis, etc. The chemical label and Material Safety Data Sheet will contain information on incompatibilities. A list of incompatible chemicals is included in Appendix B. D. Chemical Stability Stability refers to the susceptibility of the chemical to decomposition. Ethers, liquid paraffins, and olefins can form peroxides on exposure to air and light. Since these chemicals are packaged in an air atmosphere, peroxides can form even though the containers have remained sealed. Some inorganic chemicals also are unstable. Unless inhibitor was added by the manufacturer, closed containers of ethers shall be discarded after one year. See Section 3.4 - "Chemical Waste" for disposal procedures. Appropriate use of peroxide inhibitors is suggested. Examples of potential peroxide forming materials are included in Appendix A. E. Shock-Sensitive Chemicals Shock-sensitive refers to the sensitivity of the chemical to decompose rapidly or explode when struck, vibrated, or otherwise agitated. The label and Material Safety Data Sheet will indicate if a chemical is shock-sensitive. Shock-sensitive chemicals should be procured as needed to minimize storage problems. Shock-sensitive materials should be considered individually and disposed of as soon as practical. Many chemicals become increasingly shock-sensitive with age. The date received and date opened shall be clearly marked on all containers of shock-sensitive chemicals. Inhibitors are not to be added to shock-sensitive materials unless specific instructions from the manufacturer are provided. See Section 3.4 - "Chemical Waste" for disposal procedures. A partial list of potential shock-sensitive materials is included in Appendix C. F. Material Safety Data Sheets (See also Chapter 5, page 65) The Material Safety Data Sheet (MSDS) is a format for describing what chemical or product you are working with, potential chemical hazards, and ways of minimizing these hazards. These sheets shall be on hand in the laboratory for people who use these chemicals. Information that is contained in the Material Safety Data Sheets is also required by law to be conveyed to employees on a chemical-by-chemical basis. MSDSs are generally written for chemicals that are used in the industrial setting and it will become apparent that some of the information provided on the MSDS may not be applicable to laboratory usage. The use of chemicals in a laboratory is generally in a more controlled environment than in the industrial setting and much smaller quantities of the chemical are being used at any one time. Nevertheless, a great deal of information on hazards associated with laboratory chemicals can be obtained by reading the MSDS. (See also Section 9.3 - "Material Safety Data Sheets") G. Procurement of Chemicals The achievement of safe handling, use, and disposal of hazardous substances begins with the persons who requisition such substances and those who approve their purchase orders. These persons must be aware of the potential hazards of the substances being ordered, know whether or not adequate facilities and trained personnel are available to handle such substances, and should ensure that a safe disposal route exists. Before a new substance is received, information concerning its proper handling methods, including proper disposal procedures, should be given to all those who will be working with it. It is the responsibility of the laboratory supervisor to ensure that the facilities are adequate and that those who will handle any material have received proper training and education to do so safely. For most substances, Material Safety Data Sheets, which give physical property data and toxicological information, can be obtained by request to the vendor. However, the quality and depth of information on these sheets varies widely. The US Department of Transportation (DOT) requires that shippers furnish and attach DOT prescribed labels on all shipment of hazardous substances. These labels indicate the nature of the hazard(s) of the substance(s) shipped and thus provide some indication to receiving personnel of the type of hazard received. No container or cylinder should be accepted that does not have an identifying label. For chemicals, it is desirable that this label correspond to ANSI Z129.1, which requires, at a minimum, the following components: 1. Identification of contents of container; 2. Signal word and summary description of any hazard(s); 3. Precautionary information - what to do to minimize hazard or prevent an accident from happening; 4. First aid in case of exposure; 5. Spill and cleanup procedures; and 6. If appropriate, special instructions to physicians. Every effort should be made to ensure that this label remains on the container and legible. H. Spill Prevention A hazardous chemical spill means that an uncontrolled release of a hazardous chemical has occurred. The release may involve a gas, liquid, or solid, and usually requires some action be taken to control the point of release or the spread of the chemical. A chemical is hazardous if it possesses a physical or health threat to humans, the environment, or property. More specifically, a substance is considered hazardous when: a. It is flammable, explosive, or reactive; b. It generates harmful vapor or dust; c. It is a carcinogen; d. It is a corrosive and attacks skin, clothing, equipment, or facilities; e. It is poisonous by ingestion, inhalation or absorption. Spills involving hazardous materials will require different tactics depending on the magnitude of the spill, the material's toxicity, reactivity, and flammability, routes of entry of the material into the body, and the promptness with which the spill can be safely managed. For information on handling of chemical spills see Section 1.1 - "Chemical Spills." Many spills can be prevented or controlled by careful planning, use of trays, and absorbent paper. (Remember, hoods don't prevent or control spills; they just relocate them!) Proper techniques for transporting hazardous chemicals and proper storage techniques may help prevent spills. I. Handling and Transportation of Chemicals Many laboratory accidents occur through the simple operation of carrying chemicals from one place to another or transferring them from one container to another. The chemicals used in a laboratory are often corrosive, toxic, or flammable and any accident involving these has the potential for personal injury. Therefore, it is good practice to assume that all chemicals are potentially hazardous. 1. When large bottles of acids, solvents, or other liquids are transported within the laboratory without a cart, only one bottle should be carried at a time. The bottle should be carried with both hands, one on the neck of the bottle and the other underneath. Avoid the temptation to hook a finger through the glass ring on top of the bottle, allowing it to dangle while being transported. Never carry or attempt to pick up a bottle by the cap. 2. When transporting bottles within the laboratory, a wheeled cart may be used. Carts should be stable under load and have wheels large enough to negotiate uneven surfaces (such as expansion joints and floor drain depressions) without tipping or stopping suddenly. Do not place the bottles near the edge of the cart, nor should they be touching each other or other glassware during transport. Be cautious rolling the cart over door sills or other possible obstructions. Incompatible chemicals should not be transported on the same cart. A list of incompatible chemicals is included in Appendix B. 3. Freight-only elevators should be used, if possible, when transporting chemicals, to avoid exposure to persons on passenger elevators. 4. Special padded or rubber bottle carriers, pails, or carts should be used to prevent breakage by accidental striking against walls or floor, and to contain the material if breakage does occur. 5. Large quantities of concentrated mineral acids, e.g., sulfuric, nitric and hydrochloric acids, shall be kept in storage rooms, in cabinets for corrosive substances, or chemical transfer rooms. Bottles of concentrated acids must be carried from the aforementioned areas in an approved acid bottle carrier. 6. Organic solvents shall also be stored in specialized flammable storage areas. These solvents shall be carried from storage areas in special rubber carriers. Organic solvents can present fire hazards as well as inhalation hazards. 7. For information on transportation and storage of compressed gases see Section 2.4 - "Compressed Gas Safety." J. Chemical Storage The principle concerns in achieving proper storage are to maximize employee safety with regard to chemical compatibility, spill control, fire/explosion control, to provide security, identification, and provide a "user friendly" system with respect to point-of-use. 1. Every chemical in the laboratory should have a definite storage place and should be returned to that location after each use. 2. Storage must conform to compatibility restrictions as described in Appendix B. Typically, solvents, acids, bases, reactives, oxidizers, and toxins will be stored separately. Separation basically refers to physical separation of containers and isolation of potential spills and releases with the goal of preventing chemical reactions. Ideally, separate cabinets or isolated areas within a central storage area should be utilized for segregated storage of incompatibles. 3. Adequate containment for spills and accidental releases shall be provided. 4. Hazardous chemicals should never be stored on the floor. Containers should be kept on low shelves or in cabinets. The shelves should have a lip on the forward edge to prevent bottles from slipping off. Chemicals tend to "creep" toward and over the edge of a shelf. Shelving units should be securely fastened to the wall or floors. Shelves should not be overloaded. 5. Utilize a compatible/suitable container for experiments, stored chemicals and collected wastes. In instances of corrosive wastes or halogenated solvents, the use of metal containers is often unsuitable, even if the solvents were originally shipped in metal containers. In these instances, plastic carboys (high density polyethylene) or lined metal containers may be more suitable. See the Material Safety Data Sheet for specific information. 6. There shall be constant vigilance for any sign of chemical leakage. Containers storing chemical waste must be inspected weekly for any sign of chemical leakage. Containers of all types should be free of rust and deformation. 7. Caps and covers for containers shall be securely in place whenever the container is not in immediate use. 8. Storage shall be physically secure. 9. NFPA labeling shall appear on cabinets and room doors at approximately waist level or lower to allow adequate visualization in dense smoke conditions. 10. All containers used for storage (even short term) shall be labeled in accordance with Hazard Communication regulations and NFPA and University fire codes. At a minimum, all containers must be labeled with regard to content and general hazard. 11. Flammable liquids in quantities greater than one liter should be kept in metal safety cans designed for such storage. The cans should be used only as recommended by the manufacturer, including the following safety practices: a. Never disable the spring-loaded closure. b. Always keep flame-arrestor screen in place; replace if punctured or damaged. 12. Flammable liquids shall not be stored in your laboratory unit in amounts greater than the limits for flammable liquid storage given in Section 8.1 - "Standard Operating Procedures." 13. Metal drums used for storage and dispensing of flammable chemicals shall be properly grounded. Ground cables shall be available and utilized in any lab using metal storage containers for flammable liquid storage. 14. Chemicals should be stored as close as feasible to the point of use in order to maximize efficiency and minimize transport distance. Chemical storage should be limited only to areas in which the particular chemical is used. Storage locations must be identified on an emergency floor plan posted in each work area and should be equipped with a fire extinguisher, spill kit, eye wash, first aid kit, and telephone or other communication system to allow for adequate emergency notification. 15. Small quantities of chemicals can be held at individual work stations if this quantity is to be promptly used in a test and does not compromise acceptable ambient organic vapor levels or procedures for spill control and fire safety. These containers must be properly labeled. 16. Only limited quantities of chemicals and solvents should be stored in the laboratory. Large drums or multiple bottles of chemicals should be stored in a centralized chemical storage area. 17. Out-of-date chemicals shall be disposed of on a periodic basis to reduce overall hazard potential and minimize inventory tracking and updating. (See Section 3.4 - "Chemical Waste") K. Prior Approval Employees must obtain prior approval to proceed with a laboratory task from their laboratory supervisor and/or their Departmental Chemical Hygiene Officer whenever: 1. A new laboratory procedure or test is to be carried out. 2. It is likely that toxic limit concentrations could be exceeded. 3. There is a change in a procedure or test, even if it is very similar to prior practices. "Change in procedure or test" means: a. A 10% or greater increase or decrease in the amount of one or more chemicals used. b. A substitution or deletion of any of the chemicals in a procedure. c. Any change in other conditions under which the procedure is to be conducted. (Communication is critical; please ensure that colleagues remain well informed.) 4. There is a failure of any of the equipment used in the process, especially of safeguards such as fume hoods or clamped apparatus. 5. There are unexpected results. 6. Members of the laboratory staff become ill, suspect that they or others have been exposed, or otherwise suspect a failure of any safeguards. SECTION 3.2 - CHEMICAL WASTES McGill’s Office of Waste Management is responsible for coordinating the pickup of surplus and waste chemical substances from generating departments. To assure compliance with regulations, safe handling, and efficiency of operations, McGill has established the following standards applicable to the collection, storing, labeling, and packaging of these substances by departments. Under no circumstances will personnel pickup chemical substances that do not strictly follow the procedures and requirements listed in this section. EBY has been given the responsibility for determining the status of substances as surplus or hazardous wastes. (NOTE: Due to the explosive characteristics inherent to the addition of a carbon source to Ammonium Nitrate, Ammonium Nitrate should not be placed in surplus CHAPTER 4 - BIOLOGICAL SAFETY Microbiological and biohazard laboratories are special, often unique, work environments that may pose special infectious disease risks to persons in or near them. Personnel have contracted infections in the laboratory throughout the history of microbiological and biohazard research. A number of cases have been attributed to carelessness or poor technique in the handling of infectious materials. The term "containment" is used in describing safe methods for managing infectious agents in the laboratory environment where they are being handled or maintained. Primary containment, the protection of personnel and the immediate laboratory environment from exposure to infectious agents, is provided by good microbiological technique and the use of appropriate safety equipment. The use of vaccines may provide an increased level of personal protection. Secondary containment, the protection of the environment external to the laboratory from exposure to infectious materials, is provided by a combination of facility design and operational practices. The purpose of containment is to reduce exposure of laboratory workers and other persons, and to prevent escape into the outside environment of potentially hazardous agents. The three elements of containment include laboratory practice and technique, safety equipment, and facility design. A. Laboratory Practice and Technique The most important element of containment is strict adherence to standard microbiological practices and techniques. Persons working with infectious agents or infected materials must be aware of potential hazards and must be trained and proficient in the practices and techniques required for safely handling such material. The director or person in charge of the laboratory is responsible for providing or arranging for appropriate training of personnel. When standard laboratory practices are not sufficient to control the hazard associated with a particular agent or laboratory procedure, additional measures may be needed. The laboratory supervisor is responsible for selecting additional safety practices, which must be in keeping with the hazard associated with the agent or procedure. Each laboratory should develop or adopt a bio-safety or operations manual which identifies the hazards that will or may be encountered and which specifies practices and procedures designed to minimize or eliminate risks. Personnel shall be advised of special hazards and shall be required to read and follow the required practices and procedures. A scientist with training and knowledge in appropriate laboratory techniques, safety procedures, and hazards associated with handling infectious agents must direct laboratory activities. Laboratory personnel, safety practices and techniques must be supplemented by appropriate facility design and engineering features, safety equipment and management practices. 1. Engineering controls shall be examined and maintained or replaced on a regular schedule to ensure their effectiveness. 2. Employees shall wash their hands immediately or as soon as possible after removal of gloves or other personal protective equipment and after hand contact with blood or other potentially infectious materials. 3. All personal protective equipment shall be removed immediately upon leaving the work area or as soon as possible if overtly contaminated and placed in an appropriately designated area or container for storage, washing, decontamination or disposal. 4. Used needles and other sharps shall not be sheared, bent, broken, recapped, or resheathed by hand. Used needles shall not be removed from disposable syringes. 5. Eating, drinking, smoking, applying cosmetics or lip balm, and handling contact lenses are prohibited in work areas where there is a potential for occupational exposure. 6. Food and drink shall not be stored in refrigerators, freezers, or cabinets where blood or other potentially infectious materials are stored or in other areas of possible contamination. 7. All procedures involving blood or other potentially infectious materials shall be performed in such a manner as to minimize splashing, spraying, and aerosolization of these substances, and shall comply with the Blood-Borne Pathogens Act. B. Safety Equipment (Primary Barriers) Safety equipment includes biological safety cabinets and a variety of enclosed containers. The biological safety cabinet is the principal device used to provide containment of infectious aerosols generated by many laboratory procedures. Open fronted Class I and Class II biological safety cabinets are partial containment cabinets which offer significant levels of protection to laboratory personnel and the environment when used with good microbiological techniques. The gas-tight Class III biological safety cabinet provides the highest attainable level of protection to personnel and the environment.Further references on proper and effective use of biological safety cabinets may be found in Section 5.3, "Effective Use of Biological Safety Cabinets." An example of an enclosed container is the safety centrifuge cup, which is designed to prevent aerosols from being released during centrifugation. Safety equipment can also include items for personal protection such as gloves, coats, gowns, shoe covers, boots, respirators, face shields, and safety glasses. These personal protective devices are often used in combination with biological safety cabinets and other devices which contain the agents, animals, or materials being examined. In some situations in which it is impractical to work in biological safety cabinets, personal protective devices may form the primary barrier between personnel and the infectious materials. Examples of such activities include certain animal studies, animal necropsy, production activities, and activities relating to maintenance, service or support of the laboratory facility. C. Personal Protective Equipment When there is a potential for occupational exposure, the supervisor shall assure that the employee uses appropriate personal protective equipment such as, but not limited to, gloves, gowns, fluid-proof aprons, laboratory coats, head and foot coverings, face shields or masks, eye protection, mouthpieces, resuscitation bags, pocket masks, or other ventilation devices. 1. The laboratory shall assure that appropriate personal protective equipment in the appropriate sizes is readily accessible at the work site or issued to employees. Hypoallergenic gloves shall be readily accessible to those employees who are allergic to the gloves normally provided. 2. The supervisor shall shall insure the repair/replacement of personal protective equipment as needed to maintain its effectiveness. 3. Gloves shall be worn when the employee has the potential for the hands to have the direct skin contact with potentially infectious materials and when handling items or surfaces soiled potentially infectious material. a. Disposable (single-use) gloves such as surgical or examination gloves shall be replaced as soon as possible when visibly soiled, torn, punctured or when their ability to function as a barrier is compromised. They shall not be washed or disinfected for re-use. b. Utility gloves may be disinfected for re-use if the integrity of the glove is not compromised, however, they must be discarded if they are cracked, peeling, discolored, torn, punctured, or exhibit other signs of deterioration. 5. Masks and eye protection or chin-length face shields shall be worn whenever splashes, spray, spatter, droplets, or aerosols of blood or other potentially infectious materials may be generated and there is a potential for eye, nose, or mouth contamination. 6. Appropriate protective clothing shall be worn when the employee has potential for occupational exposure. The type and characteristics will depend upon the task and degree of exposure anticipated. a. Gowns, lab coats, aprons or similar clothing shall be worn if there is a potential for soiling of clothes with potentially infectious materials. b. Fluid resistant clothing, surgical caps or hoods shall be worn if there is a potential for splashing or spraying of potentially infectious materials. c. Fluid-proof shoe covers shall be worn if there is a potential for shoes to become contaminated and/or soaked with potentially infectious materials. D. Housekeeping The work site shall be maintained in a clean and sanitary condition. All equipment, environmental enclosures and working surfaces shall be properly cleaned and disinfected after contact with blood or other potentially infectious materials. 1. Work surfaces shall be decontaminated with an appropriate disinfectant after completion of procedures; when surfaces are overtly contaminated; immediately after the spill of blood or other potentially infectious materials; and at the end of the work shift. 2. Protective coverings such as plastic wrap, aluminum foil, or imperviously-backed absorbent paper may be used to cover equipment and environmental surfaces. These coverings shall be removed and replaced at the end of the work shift or when they become overtly contaminated. 3. Equipment which may become contaminated with blood or other potentially infectious materials shall be checked routinely and prior to servicing or shipping and shall be decontaminated as necessary. 4. All bins, pails, cans, and similar receptacles intended for re-use which have a potential for becoming contaminated with potentially infectious materials shall be inspected, cleaned, and disinfected on a regularly scheduled basis and cleaned and disinfected immediately or as soon as possible upon visible contamination. 5. Broken glassware which may be contaminated shall not be picked up directly with the hands. It shall be cleaned up using mechanical means such as a brush and dust pan, tongs, cotton swabs or forceps. 6. Specimens potentially infectious materials shall be placed in a closable, leak-proof container labeled or color-coded bag prior to being stored or transported. If outside contamination of the primary container is likely, then a second leak-proof container that is labeled or color-coded shall be placed over the outside of the first container and closed to prevent leakage during handling, storage, or transport. If puncture of the primary container is likely, it shall be placed in a leak-proof puncture-resistant secondary container. 7. Reusable items contaminated with potentially infectious materials shall be decontaminated prior to washing and/or reprocessing. E. Infectious Waste Disposal All infectious waste destined for disposal shall be placed in closable, leak-proof containers or bags that are color-coded (yellow for bio-hazardous wastes) and labeled. 1. If outside contamination of the container or bag is likely to occur then a second leak-proof container or bag which is closable and labeled or color-coded shall be placed over the outside of the first and closed to prevent leakage during handling, storage, and transport. 2. Disposal of all infectious waste shall be in accordance with procedures found in Section 4.2, "Biohazard/Biomedical Waste." 3. Immediately after use, sharps, i.e., broken glass, needles, pipettes, etc., shall be placed in closable, labeled leak-proof, puncture resistant, disposable containers. 4. These containers shall be easily accessible to personnel and located in the area of use. F. Bio-safety Levels Four bio-safety levels are described which consist of combinations of laboratory practices and techniques, safety equipment, and laboratory facilities appropriate for the operations performed and the hazard posed by the infectious agents and for the laboratory function or activity. Bio-safety Levels 1 and Bio-safety Level 2 are applicable to the Food Science Laboratories on the Macdonald Campus and Levels 3 and 4 are applicable the Federal Government’s Health Protection Labs in Ottawa. It is the responsibility of members of the McGill community who visit / work in the HPB facilities to become familiar and respect work protocols / norms that are practiced at these facilities. 1. Bio-safety Level 1: Practices, safety equipment, and facilities are appropriate for facilities in which work is done with defined and characterized strains of viable microorganisms not known to cause disease in healthy adult humans. Bacillus subtilis, Naegleria gruberi, and infectious canine hepatitis virus are representative of those microorganisms meeting these criteria. Many agents not ordinarily associated with disease processes in humans are, however, opportunistic pathogens and may cause infection in the young, the aged, immunodeficient or immunosuppressed individuals. Vaccine strains which have undergone multiple in-vivo passages should not be considered avirulent simply because they are vaccine strains. 2. Bio-safety Level 2: Practices, equipment, and facilities are applicable to clinical facilities in which work is done with the broad spectrum of indigenous moderate-risk agents present in the community and associated with human disease of varying severity. With good microbiological techniques, these agents can be used safely in activities conducted on the open bench, provided the potential for producing aerosols is low. Hepatitis B virus, the Salmonellae, and Toxoplasma spp. are representative of microorganism assignment to this containment level. Primary hazards to personnel working with these agents may include accidental autoinnoculation, ingestion, and skin or mucous membrane exposure to infectious materials. Procedures with high aerosol potential that may increase the risk of exposure to personnel, must be conducted in primary containment equipment or devices. 3. Bio-safety Level 3: Practices, safety equipment, and facilities are applicable to facilities in which work is done with indigenous or exotic agents where the potential for infection by aerosols is real and the disease may have serious or lethal consequences. Autoinnoculation and ingestion also represent primary hazards to personnel working with these agents. Examples of such agents for which bio-safety Level 3 safeguards are generally recommended include Mycobacterium tuberculosis, St. Louis encephalitis virus and Coxiella burnetti. 4. Bio-safety Level 4: Practices, safety equipment, and facilities are applicable to work with dangerous and exotic agents which pose a high individual risk of life threatening disease. All manipulations of potentially infectious diagnostic materials, isolates, and naturally or experimentally infected animals pose a high risk of exposure and infection to laboratory personnel. Lassa Fever virus is representative of the microorganisms assigned to Level 4. Work with known agents shall be conducted at the bio-safety level recommended by the Centers for Disease Control (CDC) or the National Institute of Health (NIH), unless specific information is available to suggest the virulence, pathogenicity, antibiotic resistance patterns, and the other factors are significantly altered to require more stringent or allow less stringent practices to be used. Clinical laboratories, and especially those in health care facilities or disease diagnostic labs, receive clinical specimens with requests for clinical support services. Typically, clinical laboratories receive specimens without pertinent information such as patient history or clinical findings which may be suggestive of an infectious etiology. Furthermore, such specimens are often submitted with a broad request for microbiological examination for multiple agents (e.g., sputum samples submitted for "routine," acid fast, and fungal cultures). It is the responsibility of the laboratory supervisor to establish standard procedures in the laboratory which realistically address the issue of ineffective hazard of clinical specimens. Except in extraordinary circumstances (e.g., suspected hemorrhagic fever) the initial processing of clinical specimens and identification of isolates can be and are safely conducted using a combination of practices, facilities, and safety equipment described as bio-safety level 2. Biological safety cabinets (Class I or II) should be used for the initial processing of clinical specimens when the nature of the test is requested or other information is suggestive that an agent readily transmissible by infectious aerosols is likely to be present. Class II biological safety cabinets are also used to protect the integrity of the specimens or cultures by preventing contamination from the laboratory environment. Segregating clinical laboratory functions and limiting or restricting access to laboratory areas are the responsibility of the laboratory supervisor. 10. Work surfaces must be decontaminated with an appropriate disinfectant after completion of procedures; when surfaces are overtly contaminated; immediately after the spill of infectious materials; and at the end of the work shift. a. Appropriate germicidals include: (1) EPA-registered "hospital disinfectant" chemical germicides that have a label claim for tuberculocidal activity, and (2) commercially available hard-surface germicides or solutions containing at least 500 parts per million free available chlorine (a 1:100 dilution of common household bleach - approximately ¼ cup of bleach per gallon of tap water). SECTION 4.1 - EFFECTIVE USE OF BIOLOGICAL SAFETY CABINETS Exposure to airborne microorganisms can result in infection of laboratory workers or contamination of research materials. Biomedical engineering and technology have provided safeguards, but these safeguards do not prevent mistakes or human errors. Danger to personnel and to the success of scientific investigation from carelessly or improperly used equipment cannot be overly emphasized. The Laminar Flow Biological Safety Cabinet, designed to prevent escape of pathogens into the workers' environment and to bar contaminants from the research work zone, is a key element to safe, successful experimentation with biological materials. Escape of pathogens into the workers' area is prevented by an air barrier at the front opening and the cleaning action of the exhaust air filter. Inward flow of room air into the front air intake grill creates the air barrier. The amount of air drawn into the air intake grill and the amount of air exhausted through the exhaust filter are equal. The exhaust filter removes airborne biological contaminants which may be released in the cabinet. It does not remove chemical or radiological contaminants. Contamination of the work area inside the cabinet is prevented by the cleaning action of the supply filters. Air flows through the cabinet work area in a downward direction at a uniform velocity. The air continues to be recirculated by the fan through the air flow plenum. Airborne biological contaminants are removed by the filters as the air is returned to the cabinet work area. Certification and advance planning are of prime importance to safe operation. Only qualified personnel using approved test methods and equipment should provide performance certification at initial installation, after maintenance, and on an annual basis thereafter. Certification is also necessary after the cabinet has been moved and after filters have been replaced. Many cabinets have gauges to indicate pressure differential across the supply filters. If the filters must be replaced, the cabinet MUST be decontaminated first. This is the responsibility of the researcher to do or have done by a qualified contractor. Procedures must follow those outlined in the National Sanitation Foundation Standard Number 49. After decontamination, only qualified Site Support personnel should replace filters. Fan speed must also be readjusted by qualified maintenance technicians. Environmental Health & Safety maintains a list of firms specializing in the decontamination and certification of biological safety cabinets. It is the responsibility of individual researchers and/or departments to insure this process is accomplished at least annually. If your biological safety cabinet has not been certified, contact EHS for a list of names and phone numbers of certification agencies. In a survey performed by a cabinet manufacturer, 65 of 100 cabinets failed to pass filtration system leak tests. The operators of these cabinets were unaware of the malfunction. Maximum safety and full use of the cabinet can be best achieved by adequate advanced planning. Ideally, advanced planning should follow a procedural check list to anticipate equipment, apparatus, media, order of events and the many other details necessary for the completion of the assignment. When planning is completed, start-up procedures may be initiated. There are three start-up steps: 1. Turn on the lights 2. Check the air intake and exhaust grill to make sure they are unobstructed 3. Turn on the fan Allow the fan to operate a minimum of five minutes before manipulations are begun in the cabinet. In addition, the following points should be considered: 1. Some cabinets are equipped with ultraviolet light. These must be turned off during the day while laboratory personnel are occupying the room. 2. Hands and arms should be washed well with germicidal soap before and after work in the cabinet. 3. Technicians are encouraged to wear long-sleeve gowns with knit cuffs and rubber gloves. This minimizes the shedding of skin flora into the work area and protects the hands and arms from contamination by viable agents. 4. Interior surfaces of the work area should be disinfected by wiping them thoroughly with 70% alcohol. 5. The cabinets should not be overloaded. Everything needed for the complete procedure should be placed in the cabinet before starting so that nothing passes in or out through the air barrier until the procedure is completed. 6. Do not place anything over the front intake or rear exhaust grill in units having a solid work surface. As a general rule, keep equipment at least four inches inside the cabinet window and perform transfer of viable materials as deeply into the cabinet as possible. 7. After all materials have been placed in the cabinet, wait 2-3 minutes before beginning work. This will allow sufficient time for the cabinet air to purge airborne contamination from the work area. 8. Hold the activity in the room to a minimum. Unnecessary activity may create disruptive air currents. The ideal location for a cabinet is in a quiet end of the laboratory, removed from doorways, air conditioning and heating vents. Opening and closing laboratory doors can cause disruptive drafts that allow microorganisms to penetrate the air barrier. 9. Schedule uninterrupted work periods. The movement of objects including hands and arms causes turbulent air currents which disrupt the air barrier and allow escape and entrance of airborne contaminants. 10. Air turbulence caused by rotating laboratory equipment, such as a small clinical centrifuge, disrupt air flow within the cabinet and at the work opening. This is sufficient for contaminated air to escape to the laboratory environment. If a centrifuge must be used in the cabinet, do not perform other research activities in the cabinet while the centrifuge is operating. 11. Normal laboratory contamination control procedures and aseptic techniques are still necessary while working in the biological safety cabinet. 12. Equipment in direct contact with the biological agent should not be removed from the cabinet until enclosed or until the surface is decontaminated. Trays of discarded pipettes and glassware must be covered before removal from the cabinets. 13. If an accident occurs which spills or splatters the biological agent in the work area, all surfaces in the cabinet must be surface decontaminated before being removed. 14. Do not use a Bunsen Burner in a biological safety cabinet. The flame causes turbulence in the air stream and the heat generated may damage the HEPA filter. If a procedure requires the use of a flame, a burner with a pilot light should be used. It should be placed to the rear of the work space where resulting air turbulence will have a minimal effect. 15. Do not mouth pipette. 16. Following completion of the work, the following steps must be performed: A. Allow the cabinet to run 2-3 minutes with no activity. This will allow sufficient time for cabinet air flow to purge airborne contaminants from the work area; B. Decontamination of the interior surfaces should be repeated after removal of all materials, cultures, apparatus, etc. A careful check of the work area should be made for spilled or splashed nutrients. They may support fungus growth and result in spore liberation that contaminates the protected work environment; and C. Shut down by turning off the fan and lights. Use UV lights according to manufacturer's recommendations. Do not use the cabinet to store excess laboratory equipment. Myths, Lies, and Gobbledygook* "I've got to use a Bunsen Burner in my biohazard cabinet..." Using a Bunsen Burner in a biohazard cabinet compromises the performance of the unit and may be dangerous. During operation, the flame of a burner is very disruptive to the air flow patterns of the cabinet, and may actually increase the dispersion of aerosols in the work area. In addition, if the flame of the burner is too large, the excessive heat may melt in adhesive holding the HEPA filter together or literally burn holes in the filter media. (Yes, it does happen on a regular basis.) Finally, a Bunsen Burner in a biological safety cabinet is just plain dangerous. An unattended burner may blow out. If in a Type A or A/B3 cabinet, the recirculating gas may reach explosive concentrations (that has also happened on several occasions). Labconco recommends using alternative methods such as electric incinerators, or disposable inoculating hoops, for instance. The practice of flaming bottle mouths is unnecessary, as the work area of a Biohazard Cabinet should be a sterile environment, if used properly. "I can use a biological safety cabinet just as if it were a fume hood..." No. The biohazard cabinet and the chemical fume hood are two distinctly different pieces of equipment and MUST be used differently. The fume hood is designed to remove noxious or toxic fumes and aerosols away from the operator. It should be constructed of materials that are inert to a wide variety of chemical agents. The biohazard cabinet's primary purpose is to protect the operator, environment, and often the product from biohazardous contaminants. The biohazard cabinet and its HEPA filters are constructed of materials that are inert to the chemicals used in connection with biological research, but may be damaged by some of the more corrosive chemicals commonly used in fume hoods. Don't try to use a Biohazard Cabinet as a Fume Hood! "If I work in a biohazard cabinet, I don't have to be as careful with my technique..." Wrong. The biohazard cabinet will provide personal and product protection only if used properly. Aseptic technique must be practiced at all times while working in a biohazard cabinet. "I use the cabinet's UV light, so I don't need to decontaminate the work area..." Wrong. The UV light is only good as an adjunct, to minimize contamination of the work area when the cabinet is not in use. Ultraviolet light has virtually no penetrating power, and as such, will not kill microbes protected by dust, dirt, or organic material. The best method to prevent contamination in the cabinet is regular decontamination of the work area surfaces, before and after the cabinet is used. "Can I put a centrifuge in the biohazard cabinet?" Large objects placed in the biohazard cabinet will impede the airflow in the work area, reducing the efficiency of the cabinet. Electrical appliances like centrifuges, blenders, etc., will often disrupt the airflow around them due to their cooling fans. It is better to use a primary barrier on the appliance (such as a sealed safety cup in the centrifuge) rather than a biohazard cabinet to provide containment. "A total exhaust biohazard cabinet will give better protection than a Type A cabinet..." If you're talking about protection from volatile toxic chemicals or radionuclides, you're right. If you're referring to protection from biohazardous aerosols, you may not be. Assuming that the units in question are both NSF listed, then both are subjected to the same biological challenge tests. Any claims for superior biological containment should be documented by additional biological challenge test data. "There's nothing wrong with using the biohazard cabinet to store material when not in use." Yes there is. Storing chemicals and materials in the biohazard cabinet make it more difficult to use when the need arises. If chemicals leak while stored in the cabinet, the work area of the cabinet could be damaged. Don't use the biohazard cabinet as a storage area. "All biohazard cabinets should operate continuously, 24 hours-a-day." Some applications of the biohazard cabinet require that the unit operate continuously. When used to prepare cytotoxic drugs, for example, the unit should operate continuously, to prevent toxic residue form migrating out of the cabinet ductwork and into the laboratory. If the cabinet is not used in such an application, there is no need to leave it operating continuously. This will only reduce the life of the cabinet blower and HEPA filters. "If I leave my Type A cabinet running continuously, it will clean all the air in the room to Class 100 conditions." Not necessarily. Assuming you had an air-tight room, with no ventilation system, an air-tight door seal, and no activity in it, then a recirculating Type A cabinet might clean the room to Class 100 levels. This would also unfortunately shorten the operating life of the motor and HEPA filters (and heat up the room considerably). Regardless, as soon as the operator opens the room door to enter, particulate-laden air will contaminate the room, raising it far above Class 100 conditions. * Adapted from Labconco Biological Safety Cabinet Training Program, Version 1.0, 3/91.


A. Biohazard Wastes are discarded materials "that are biological agents or conditions (as an infectious organism or unsecure laboratory condition) that constitutes a hazard to man or his environment." This definition includes "any and all substances which contain materials to which organisms may cause injury or disease to man or his environment, but which are not regulated as controlled industrial waste". B. Chemical Wastes subject to the requirements of biohazard waste regulations include wastes from the following categories: - laboratory reagents contaminated with infectious fluids, - all the disposable materials which have come into contact with cytotoxic/antineoplastic agents during the preparation, handling, and administration of such agents, and - other chemicals that may be contaminated by infectious agents, as designated by experts at the point of generation of the waste. C. Treated Biohazard Wastes are all biohazard wastes that have been treated by one of the following methods and rendered harmless and biologically inert: - incineration in an approved incinerator, - steam sterilization at sufficient time and temperature to destroy infectious agents in waste ("autoclaved"), - chemical disinfection where contact time, concentration, and quantity of the chemical disinfectant are sufficient to destroy infectious agents in the waste, and - any other method approved by the Oklahoma State Department of Health and is generally recognized as effective. D. Sharps are used in animal or human patient care or treatment or in medical research, or industrial laboratories, including: hypodermic needles, syringes, (with or without the attached needle), pasteur pipettes, scalpel blades, suture needles, blood vials, needles with attached tubing, and culture dishes (regardless of presence of infectious agents). Also included are other types of broken or unbroken glassware that were in contact with infectious agents, such as used slides and cover slips. . Guidelines for Disposal 1. If any infectious waste is also a chemical waste, call EHS for assistance with disposal after disinfection. Antineoplastic/cytotoxic agents require special disposal. See Appendix L for details on handling these wastes. 2. Biomedical wastes that are also radioactive should be treated according to requirements for both biomedical and radioactive waste. 3. Prior to any treatment, all biomedical wastes, including those to be incinerated, should be enclosed in a puncture-resistant, red biohazard bag that is color-coded or labeled with the biological hazard symbol. 4. All sharps intended for disposal, whether contaminated or not, must be enclosed in a specially designed sharps container. Never clip or recap needles before putting them in the sharps container. The sharps container should be puncture-resistant, leak proof on the sides and bottom, and color-coded or labeled with the biohazard symbol. When selecting sharps containers, look for special safety features such as lids that lock tight for safe disposal, a container that can be sterilized by steam, gas, or chemicals, and a clear top that would allow inspection. If sharps containers are not specifically constructed to be autoclaved, the resulting mass of melted plastic is extremely hazardous due to the needles that often protrude. 5. Untreated biomedical waste is not to be disposed of in the municipal waste stream. All biomedical waste, including sharps and syringes, must be treated by incineration, steam sterilization, or chemical disinfection before disposal in the municipal waste stream. 6. After disinfection, but before disposal in the municipal waste stream, all treated biomedical wastes should be enclosed in an unmarked outer bag that is not red or labeled with the biohazard symbol. Any biomedical waste that has been treated as described above and packaged such that it is clearly evident that the waste has been effectively treated, is not subject to regulation as biomedical waste and may be collected, transported, and disposed of as municipal waste.


Material Safety Data Sheets generally have nine parts associated with them. These parts will not necessarily appear in the following order. 1. Basic information on the manufacturer or distributor and identification of the chemical. This includes trade name, chemical name, any synonyms or other names associated with the chemical, chemical family, CAS name, CAS registry number, and the manufacturer. 2. The product's hazardous ingredients; whether it is an OSHA-regulated chemical, the degree of toxicity, and the statement of a Permissible Exposure Level (PEL) or Threshold Limit Value (TLV). 3. Information in the MSDS on the physical data of the pure chemical and/or mixture includes boiling point, specific gravity, vapor density, volatility, general appearance, pH, melting point, vapor pressure, solubility in water, evaporation point, color, and odor. 4. Included in the fire and explosion data are flash point, auto-ignition temperature, explosion/flammable limits (LEL, UEL), fire and explosion hazards, extinguishing media, and other special instructions. 5. The potential reactivity of the product includes instability or incompatibility, potential decomposition products, and/or polymerization data. 6. Health hazard information: Lethal concentration doses, potential problems of eye and skin contact, inhalation, ingestion, and other modes of entry. 7. Protection information: Is a fume hood or other personal protective equipment, i.e., respirator, gloves, goggles, aprons, boots, etc., required? 8. What to do in case of a spill or leak including disposal procedures. (Always check local requirements.) 9. Additional information not covered by the above. Each person should read each MSDS for chemicals in their work place. The workers shall then print their names in the space provided on the MSDS Training Log Sheet for that MSDS, sign in the space provided, and date their signature. APPENDIX A POTENTIAL PEROXIDE-FORMING CHEMICALS Acetal Ether (Glyme) Cyclohexene Ethylene Glycol Dimethyl Ether Decahydronaphthalene Tetrahydronaphthalene Diacetylene Methyl Acetylene Dicyclopentadiene Isopropyl Ether Diethyl Ether Tetrahydrofuran Diethylene Glycol Sodium Amide Dimethyl Ether Vinyl Ethers para-Dioxane Vinylidene Chloride Divinyl Acetylene


INCOMPATIBLE CHEMICALS Chemical Keep out of Contact With: Acetic Acid Nitric acid, hydroxyl compounds, ethylene glycol, perchloric acid, peroxides, permanganates Acetylene Chlorine, bromine, copper, fluorine, silver, mercury Alkali Metals Water, carbon tetrachloride or other chlorinated hydrocarbons, carbon dioxide, the halogens Ammonia, Anhydrous Mercury, chlorine, calcium hypochlorite, iodine, bromine, hydrofluoric acid Ammonium nitrate Acids, metal powders, flammable liquids, chlorates, nitrites, sulfur, finely divided organic or combustible materials Aniline Nitric acid, hydrogen peroxide Bromine Same as chlorine: ammonia, acetylene, butadiene, butane, methane, propane (or other petroleum gases), hydrogen, sodium carbide, turpentine, benzene, finely divided metals Butyl lithium Water. Carbon, activated Calcium hypochlorite, all oxidizing agents Chlorates Ammonium salts, acids, metal powders, sulfur, finely divided organic or combustible materials Chromic Acid Naphthalene, camphor, glycerin, turpentine, alcohol, flammable liquids in general Chlorine Same as bromine: ammonia, acetylene, butadiene, butane, methane, propane (or other petroleum gases), hydrogen, sodium carbide, turpentine, benzene, finely divided metals Chlorine dioxide Ammonia, methane, phosphine, hydrogen sulfide Copper Acetylene, hydrogen peroxide Cumene hydroperoxide Acids, organic or inorganic Cyanides (Na, K) Acids Flammable liquids Ammonium nitrate, chromic acid, hydrogen peroxide, nitric acid, sodium peroxide, halogens, other oxidizing agents Hydrocarbons Fluorine, chlorine, bromine, chromic acid, sodium peroxide Hydrocyanic acid Nitric acid, alkalis Hydrofluoric acid Ammonia, aqueous or anhydrous Hydrogen peroxide Copper, chromium, iron, most metals or their salts, alcohols, acetone, organic materials, aniline, nitromethane, flammable liquids, oxidizing gases Hydrogen sulfide Fuming nitric acid, oxidizing gases Iodine Acetylene, ammonia (aqueous or anhydrous), hydrogen Mercury Acetylene, fulminic acid, ammonia Nitric Acid Acetic acid, aniline, chromic acid, hydrocyanic acid, hydrogen sulfide, flammable liquids, flammable gases Oxalic acid Silver, mercury Perchloric acid Acetic anhydride, bismuth and its alloys, alcohol, paper, wood, sulfuric acid, organics Potassium Carbon tetrachloride, carbon dioxide, water Potassium permanganate Glycerin, ethylene glycol, benzaldehyde, sulfuric acid Silver Acetylene, oxalic acid, tartaric acid, ammonium compounds Sodium Carbon tetrachloride, carbon dioxide, water Sodium peroxide Ethyl or methyl alcohol, glacial acetic acid, acetic anhydride, benzaldehyde, carbon disulfide, glycerin, ethylene glycol, ethyl acetate, methyl acetate, furfural Sulfuric acid Potassium chlorate, potassium perchlorate, potassium permanganate (or compounds with similar light metals, such as sodium, lithium, etc.) APPENDIX C POTENTIAL SHOCK-SENSITIVE CHEMICALS Acetylides of heavy metals Fulminate of silver Aluminum ophorite explosive Fulminating gold Amatol explosive (sodium amatol) Fulminating mercury Ammonal Fulminating silver Ammonium nitrate Fulminating platinum Ammonium perchlorate Gelatinized nitrocellulose Ammonium picrate Guanyl nitrosamino guanyl tetrazene Ammonium salt lattice Guanyl nitrosamino guanylide hydrazine Calcium nitrate Heavy metal azides Copper Acetylide Hexanite Cyanuric triazide Hexanitrodiphenylamine Cyclotrimethylenetrinitramine Hexanitrostilbene Cyclotetramethylenetranitramine Hexogen (Cylclotrimethylenetrinitramine) Dinitroethyleneurea Hydrazoic acid Dinitroglycerine Lead azide Dinitrophenol Lead mannite Dinitrophenolates Lead picrate Dinitrophenyl hydrazine Lead salts Dinitroresorcinol Lead styphnate Dinitrotoluene Magnesium ophorite Dipicryl sulfone Mannitol hexanitrate Dipicrylamine Mercury oxalate Erythritol tetranitrate Mercury tartrate Fulminate of mercury Mononitrotoluene Nitrated carbohydrate Silver styphnate Nitrated glucoside Silver tetrazene Nitrated polyhydric alcohol Sodatol Nitrogen trichloride Sodium amatol Nitrogen triiodide Sodium dinitro-ortho-cresolate Nitroglycerin Sodium nitrate-potassium nitrate explosive mixtures Nitroglycol Sodium picramate Nitroguanidine Styphnic acid Nitroparaffins Tetrazene (guanyl nitrosamino guanyl tetrazene) Nitromethane Tetranitrocarbazole Nitronium perchlorate Tetrytol Nitrourea Trimethylolethane Organic amine nitrates Trimonite Organic nitramines Trinitroanisole Organic peroxides Trinitrobenzene Picramic acid Trinitrobenzoic acid Picramide Trinitrocresol Picratol explosive (ammonium picrate) Trinitro-meta-cresol Picric acid Trinitronaphthalene Picryl chloride Trinitrophenol Picryl fluoride Trinitrophloroglucinol Polynitro aliphatic compounds Trinitroresorcinol Potassium nitroaminotetrazole Tritronal Silver acetylide Urea nitrate Silver azide APPENDIX D NEUTRALIZATION OF SPENT ACIDS AND BASES Spent mineral acids, straight-chain fatty acids, and bases (hydroxides) comprise a large portion of the unwanted chemicals being stored in campus laboratories. As a part of regular laboratory procedures, campus labs should neutralize spent inorganic acids, acetic acid, straight-chain fatty acids, and bases (hydroxides) that do not contain metal or organic contaminants. These chemicals will be managed in an "elementary neutralization unit" and, therefore, are not considered a part of the hazardous waste stream for the campus. An "elementary neutralization unit" is a container used for neutralizing corrosive wastes. Neutralization is a relatively simple procedure that is best done by and in the laboratory that uses inorganic acids, acetic acid, straight-chain fatty acids, and bases (hydroxides) on a regular basis. The laboratory that generates spent corrosives usually has the facilities and expertise to neutralize them, and therefore will be responsible for doing so. The following procedures (see A - D)describe the proper technique for neutralization of spent inorganic acids, acetic acid, straight-chain fatty acids, and bases (hydroxides) as a part of regular laboratory procedures. At the end of this appendix are lists of corrosives to be managed in-house by campus laboratories. Aqueous corrosive wastes shall NOT contain sulfides, cyanides, metals, or other materials that can give off hazardous fumes upon reaction with the acid or base. Do NOT use these procedures for: - INORGANIC ACIDS THAT CONTAIN HEAVY METALS (e.g., Atomic Absorption Standards, arsenic, cadmium, chromium, lead, mercury, nickel, selenium, silver, thallium. Solutions containing sodium, potassium, magnesium, iron can be neutralized as long as the anion is also non-hazardous.) - ESTERS OF INORGANIC ACIDS - CHROMIC ACID - PERCHLORIC ACID - HYDROFLUORIC ACID - ORGANIC ACIDS EXCEPT ACETIC ACID AND STRAIGHT-CHAIN FATTY ACIDS - LARGE QUANTITIES OF NITRIC ACID Chemicals shall not be disposed in the sanitary sewer for two reasons. First, Stillwater does not allow the disposal of most chemicals in the wastewater flow. Second, strong reactions can take place if the chemical carries unknown contaminants or contacts an incompatible chemical in the wastewater. A. Equipment Needed for Neutralizing Acids and Bases 1. Sodium carbonate (Soda ash), baking soda, or diluted inorganic base (hydroxide) for neutralization of an acid, or a diluted inorganic acid for neutralization of a base. 2. Polyethylene bucket - 1 or 2 gallon size, as personal preference dictates. Remember that 1 gallon weighs approximately 8 pounds or greater. 3. Protective equipment (goggles, apron, gloves). 4. 500 ml beakers. 5. pH Indicator Strips, or other pH test method. B. Personal Protective Equipment Read the Material Data Safety Sheet (MSDS) for detailed information. Call the Environmental Health Services Department Hazard Communications Section if an MSDS is not available. The MINIMUM recommended personal protection needed when performing the neutralization procedure is: Ventilation Work in a fume hood Gloves Use neoprene, natural rubber, butyl, polyethylene, nitrile butadiene, or polyvinyl chloride depending on the MSDS information Clothing Apron (rubber is preferred), lab coat (or protective suit or coveralls), and closed-toe shoes. Eye Protection Splash-proof or dust-proof goggles AND a face-shield (8 inch minimum) Hands shall always be washed after working with these chemicals. An eyewash station and quick-drench facility shall be located in the area. All employees shall locate these emergency facilities before starting to work. WARNING: REMEMBER THAT EXTREME HEAT CAN BE PRODUCED BY THIS PROCEDURE UNLESS IT IS DONE VERY SLOWLY AND WELL-DILUTED. CLOSELY MONITOR THE AMOUNT OF HEAT PRODUCED BY TOUCHING THE OUTSIDE OF THE NEUTRALIZATION CONTAINER. USE ICE BATH IF NECESSARY. C. Neutralization Procedure for Acid 1. Make a saturated solution of sodium carbonate (soda ash) in a beaker or use an inorganic base diluted in water (1:10 ratio) - set aside. 2. Put tap water into 1 or 2 gallon polyethylene bucket. 3. Dilute acid at least 1:10 (1 part acid to 9 parts of water) by slowly pouring and stirring the acid into the water . 4. Slowly add soda ash or other basic solution into diluted acid with stirring, or save diluted acid to neutralize bases as described below. 5. Monitor pH with pH meter, pH indicator strips, or other pH test method. 6. When pH is between 6 and 9, dispose in a drain followed with excess water. A pH near 7 is preferred to reduce the possibility of plumbing damage. HELPFUL HINT: When neutralizing an acid, the pH can be tested quickly by the following method. Make a saturated solution of sodium bicarbonate in water. A small amount of sodium bicarbonate solution poured into the acid will make a "fizz", which is a release of carbon dioxide. Since carbon dioxide evolves from these procedures, insure adequate ventilation is available. This "fizz" will indicate that the solution is still acidic, and needs more base to be added. Always stir the mixture and do a final check of the pH before pouring the neutralized acid down the drain. D. Base Neutralization 1. Put tap water into 1 or 2 gallon polyethylene bucket. 2. Dilute alkali wastes at least 1:10 (1 part alkali to 9 parts water) by slowly pouring and stirring the base into the water . 3. Neutralize the diluted alkali solution with a previously diluted inorganic acid. 4. Monitor pH with pH meter, pH indicator strips, or other pH test method. 5. When pH is between 6 and 9, dispose in a drain followed with excess water. A pH near 7 is preferred to reduce the possibility of plumbing damage. INORGANIC ACIDS NAME/MOLECULAR WT. FORMULA SYNONYMS Sulfuric Acid H2SO4 Dipping Acid M.W. - 98.08 Oil of Vitrol Sulphuric Acid Nordhausen Acid Boric Acid BH3O3 Boracic Acid M.W. - 61.84 Orthoboric Acid Nitric Acid HNO3 Aqua Fortis M.W. - 63.02 Azotic Acid Hydrogen Nitrate Hyponitrous Acid H2N2O2 Hydrochloric Acid HCl Chlorohydric Acid M.W. - 36.46 Hydrochloride Muriatic Acid Aqua Regia HCL/HNO3 Nitrohydrochloric Acid (3:1 mixture) Nitromuriatic Acid Phosphoric Acid H3PO4 Orthophosphoric Acid M.W. - 98.00 INORGANIC BASES NAME/MOLECULAR WT. FORMULA SYNONYMS Aluminum Hydroxide Al(OH)3 Alumigel M.W. - 78.01 Alumina Hydrate Alumina Trihydrate Aluminum Hydrate Aluminum(III) Ammonium Hydroxide NH4OH Ammonia Aqueous Hydroxide Aluminum Oxide-3H20 Aluminum Trihydroxide Calcium Carbonate CaCO3 Precipitated Chalk M.W. - 100.09 Chalk Dolomite Limestone/Marble Calcium Hydroxide Ca(OH)2 Slaked Lime M.W. - 74.10 Lime Water Hydrated Lime Calcium Hydrate Calcium Oxide CaO Lime M.W. - 56.08 Burnt Lime Calcia Calx Lime, Unslaked Quicklime Magnesium Carbonate MgCO3 Carbonate Magnesium M.W. - 84.32 Magnesia Alba Magnesium Carbonate- (Precipitated) Magnesium Hydroxide Mg(OH)2 Magnesia Magma M.W. - 58.33 Magnesium Hydrate Milk of Magnesia Potassium Hydroxide KOH Caustic Potash M.W. - 56.11 Lye Potassium Hydrate Sodium Bicarbonate NaHCO3 Baking Soda M.W - 85.01 Bicarbonate of Soda Sodium Acid Carbonate Sodium Carbonate Na2CO3 Soda Ash M.W - 105.99 Crystol Carbonate Carbonic Acid - Disodium Salt Sodium Hydroxide NaOH Lye M.W. - 40.00 Caustic Soda Soda Lye Sodium Hydrate APPENDIX E CLEANING SOLUTION FOR LABORATORY GLASSWARE Laboratories using chromic acid for cleaning laboratory glassware should begin to abandon the practice as soon as possible for two reasons. First, the City of Stillwater has placed limitations on the concentration of chromium in wastewater discharge (1 mg/l hexavalent chromium; 5 mg/l total chromium). Second, the costs for proper treatment and disposal of the spent cleaning product can be expensive and shall be avoided, if possible. Spent (waste) cleaning products which contain potassium/sodium dichromate in sulfuric acid or the product Chromerge shall not be discharged into the wastewater treatment system; these materials shall be collected, marked & labeled, and disposed of as a hazardous waste. Therefore, due to the difficulties involved in treatment and disposal and management of spent cleaning solutions, the OSU Environmental Health Services Department Hazardous Materials Section recommends the following: Laboratories should seek alternative glassware cleaning solutions for products to meet their needs. Glassware cleaning products which do not contain chromium such as Nochromix are readily available and are recommended. Nochromix mixed with sulfuric acid is as effective as Chromerge in removing trace metals and enzyme residues, but it eliminates the need for special handling caused by the toxicity of Chromerge. In fact, spent solutions of Nochromix can be safely disposed of (after elementary neutralization) via the sanitary sewer if not contaminated with other metals or toxic substances. The cost of Nochromix is approximately one-third of that for Chromerge. Similar substitutes might also be available from other manufacturers. Purchasers of reagents and chemicals for the affected laboratories should determine if their suppliers can provide such environmentally suitable glassware cleaning agents. As an alternative to a sulfuric acid bath, a 95% Ethanol/Hydrochloric Acid bath or 95% Ethanol/Potassium Hydroxide bath can be used effectively against organic residues. (Caution: This procedure may etch glassware.) In cases where it is imperative that glassware must be cleaned using a cleaning solution containing chromium, the spent cleaning reagent is classified as a hazardous waste. This procedure will also be considered a special procedure (see Section 8.2 - "Special Procedures"). Please convey this information to persons in your area who may utilize chromic acid cleaning solutions. Your cooperation is this matter is solicited to help minimize the costs of disposal for regulated wastes. Please contact Environmental Health Services, Hazardous Materials Section, if you have any questions. APPENDIX F SAFETY SURVEY LIST Working Areas 1. Adequate lighting in the work area? 2. Laboratory work areas reasonably clean and tidy? 3. Area kept as clean as work allows? 4. Guards on fan blades that are located within 7 ft. of the floor? 5. Ladders and step-stools in good condition and used in the manner for which they were designed? 6. Two and four-wheeled carts and hand trucks in good condition? 7. List of emergency numbers, First Aid, and CPR certified employees clearly displayed? 8. No foods, beverages, tobacco, or cosmetics in laboratory? 9. Eating, drinking, use of tobacco, and use of cosmetics prohibited in the laboratory? 10. No chipped or broken glassware in use? Means of Egress 11. Sidewalks kept free of snow and ice? 12. Stairs well lit? 13. Stairs of sturdy design? 14. Railings provided on all open sides of exposed stairways? 15. Anti-skid walking surfaces on the stairs? 16. Stairs clean? 17. All non-exit doors and passages which could be mistaken for an exit marked as such? 18. All exits clearly designated? 19. All exits unobstructed? 20. All exit signs illuminated? (They must be illuminated by general room lighting or internal lighting.) 21. Emergency lighting provided for fire escape routes? 22. All fire doors unobstructed and free of locks and devices that could prevent free egress? 23. Designated fire doors closed and operable? 24. All fire doors side hinged and swing in the direction of the escape? 25. Floors free from protrusions and large holes? 26. Floors free from litter and obstructions? 27. Floors clean and dry? 28. Drainage provided for continuously wet floors? 29. Mats and carpeting in good condition? 30. Aisles and passageways well lit? 31. Aisles and passageways kept clear to provide safe movement of materials handling equipment or employees? 32. No loose or protruding shelving or edging that could cause a safety problem? 33. Covers or guard rails provided for open pits, vats, etc.? 34. Guard rails provided for platforms greater than 4 feet above the adjacent floor? Materials Handling and Storage 35. Area free of the accumulation of materials that could cause tripping, fires, explosions, or pest harboring? 36. Sprinklers clear of stored materials (18 inch clearance)? 37. NFPA 704 labeling appears on doors and cabinets? 38. Materials stored to prevent sliding, falling, or collapse? 39. Storage shelving secure, in good condition, and not over-loaded or crowded? 40. Storage shelving provided with a lip on forward edge? 41. Hazardous chemicals not stored on floor? 42. Sufficient waste containers provided? 43. A closable metal container provided for oily rags (if necessary)? 44. Reagents used at the bench properly labeled to prevent accidental use of the wrong reagent or wash bottle? 45. Containers labeled with the identity of contents and general hazard(s) of contents? 46. Containers properly capped or sealed? 47. Flammable liquids in quantities greater than one liter stored in safety cans designed for flammable liquid storage? 48. Flammable and combustible liquids stored in containers labeled as such? 49. Flammable and combustible liquids stored in approved cabinets marked "Flammable"? 50. Cabinets properly ventilated? 51. If flammable liquids are used in large volumes, is the mechanical ventilation adequate to remove vapors before they reach hazardous concentrations? 52. Stored combustibles and flammables separated from any heat source by at least 20 feet? 53. Areas where flammables are used or stored designated "NO SMOKING - NO OPEN FLAMES"? 54. Metal drums used for storage and dispensing of flammable liquids properly grounded? 55. Materials stored only with other compatible materials? (e.g., solvents, acids, bases, reactives, oxidizers, and toxins stored separately) Compressed Gases 56. Each compressed gas cylinder marked with the identity of its contents? 57. Compressed gas cylinders inspected visually for safe operating condition? 58. Gas cylinders secured so they will not tip over or fall? 59. Valve caps in place on all gas cylinders that are not in use? 60. All gas lines leading from compressed gas supplies labeled as to identity of gas, laboratory served, and emergency telephone numbers? 61. Gas cylinder storage areas properly ventilated? 62. Areas where flammable compressed gases are stored posted "NO SMOKING - NO OPEN FLAMES"? 63. Oxygen cylinders not stored in the same vicinity of greasy or oily rags? 64. Oxygen cylinders stored a minimum of 50 feet from flammable gas cylinders or a minimum five feet high fire wall with a 0.5 hour fire rating separates them? Electrical 65. All electrical equipment properly grounded? (Double insulated tools are exempt.) 66. All electrical equipment U.L. listed and/or F.M. approved? 67. Breaker boxes that may need maintenance while live have a minimum of 30" width clearance in front of them? 68. All circuit breakers and fused circuits labeled to indicate whether they are in the open (off) or closed (on) position? 69. Properly rated fuses used? 70. All electrically live parts guarded? Electrical boxes and panels covered with face-plates to prevent exposure to live wires? 71. Tool, appliance, instrument, and extension cords in good repair? 72. Has permanent wiring been installed to alleviate the use of extension cords? 73. Electrical cords or other lines not suspended unsupported across rooms or passageways? 74. Cords not routed over metal objects? 75. Cords not run through holes in walls or ceilings or through doorways or windows? 76. Cords not placed under carpet, rugs, or heavy objects? 77. Cords not placed in pathways or other areas where repeated abuse can cause deterioration of insulation? 78. Octopus (multi-outlet) plugs not used? Approved multiple outlets with circuit breakers used instead? General Safety Equipment 79. Fire extinguishers located where flammable or combustible liquids are used? 80. A fire extinguisher located between 10 feet and 25 feet of a door opening to rooms used for storage? 81. Other extinguishers ready and accessible? 82. Extinguishers mounted so that the top is not more than 5 feet above the floor, and not more than 3 feet if it weighs more than 40 lbs? 83. Extinguishers suitable for the class of fire anticipated in each area? 84. Extinguishers inspected and labeled as inspected on a yearly basis? 85. Employees instructed in the proper use of fire extinguishers on an annual basis? 86. Fire alarm boxes readily accessibly and within normal path distance of 200 feet. 87. Fire alarm system tested on an annual basis? 88. Eyewash and safety showers installed within 25 feet of laboratory work areas where corrosive chemicals are used? 89. Safety showers and eyewash fountains easily accessible? 90. Employees familiar with operation of safety showers and eyewash fountains? 91. Safety showers and eyewash fountains tested at least annually? 92. First aid kits available, in good condition, and plainly marked? 93. Explosion-proof refrigerators not used for storage of food? 94. Fume hoods in proper operating condition? 95. Function of fume hoods periodically checked and results recorded and posted? 96. Equipment properly placed in fume hoods? (i.e., nothing within 6 inches of sash and all instruments elevated a minimum of 2 inches from hood floor.) 97. Fume hoods not used for storage? Personal Protection 98. Eye protection provided and used by all personnel when in the laboratory area? 99. Eye protection provided for all guests that enter the laboratory? 100. Proper laboratory clothing provided and used by all personnel when in the laboratory area? 101. Laboratory clothing clean and in good repair? 102. Gloves provided and used when needed? 103. Proper gloves provided for each different solvent type? 104. Employees who are required to wear steel toe shoes comply? 105. Area provided outside the laboratory for eating and drinking; lab coats and protective clothing prohibited in this area? 106. Change rooms provided for each sex where it is necessary to change clothes? 107. Change rooms provided with separate storage facilities for street clothes and protective clothing? 108. Personal hygiene facilities provided and kept in sanitary condition? Other 109. Noise levels checked and protection provided when needed? GLOSSARY AA spectrophotometer Atomic absorption spectrophotometers Action level A concentration for a specific substance, calculated as an eight (8) hour time-weighted average, which initiates certain required activities such as exposure monitoring and medical surveillance. Typically it is one-half that of the PEL for that substance. Acute Exposure Single exposure episodes which occur over a short time period. ANSI The American National Standards Institute is a voluntary membership organization (run with private funding) that develops consensus standards nationally for a wide variety of devices and procedures. ASHRAE American Society of Heating, Refrigeration and Air Conditioning Engineers Asphyxiant A chemical (gas or vapor) that can cause death or unconsciousness by suffocation. Simple asphyxiants such as nitrogen, either use up or displace oxygen in the air. They become especially dangerous in confined or enclosed spaces. Chemical asphyxiants, such as carbon monoxide and hydrogen sulfide, interfere with the body's ability to absorb or transport oxygen to the tissues. Biohazard Wastes Discarded materials "that are biological agents or conditions (as an infectious organism or unsecure laboratory condition) that constitutes a hazard to man or his environment." This definition includes "any and all substances which contain materials to which organisms may cause injury or disease to man or his environment, but which are not regulated as controlled industrial waste." "C" or Ceiling A description usually seen in connection with a published exposure limit. It refers to the concentration that should not be exceeded, even for an instant. It may be written as TLV-C or Threshold Limit Value--Ceiling. (See also Threshold Limit Value). Carcinogen Any substance that causes the development of cancerous growths in living tissue, either those that are known to induce cancer in man or animals or experimental carcinogens that have been found to cause cancer in animals under experimental conditions. C.A.S. Number Identifies a particular chemical by the Chemical Abstracts Service, a service of the American Chemical Society that indexes and compiles abstracts of worldwide chemical literature called "Chemical Abstracts". These numbers are always contained in brackets. CDC Centers for Disease Control CFR Code of Federal Regulations Chemical Hygiene Plan A written program developed and implemented by the employer which sets forth procedures, equipment, personal protective equipment and work practices that are capable of protecting employees from the health hazards presented by hazardous chemicals used in that particular work place and meets the requirements of 29 CFR 1910.1450(e). CHP See Chemical Hygiene Plan Chemical Reaction A change in the arrangement of atoms or molecules to yield substances of different composition and properties. (See Reactivity). Chronic Exposure A series of exposures occurring over a longer period of time. Combustible A combustible liquid or an "Ordinary Combustible" such as wood, paper, etc. Combustible Liquid Any liquid having a flashpoint at or above 100 oF (37.8 oC), but below 200 oF (93.3 oC), except any mixture having components with flashpoints of 200 oF (93.3 oC), or higher, the total volume of which make up 99 percent or more of the total volume of the mixture. Corrosive Any gas, liquid, or solid that causes destruction of human tissue or a liquid that has a severe corrosion rate on steel. Generally, a substance that has a very low or a very high pH. Cutaneous Pertain to or affecting the skin. Decomposition The breakdown of a chemical or substance into different parts or simpler compounds. Decomposition can occur due to heat, chemical reaction, decay, etc. Dermal Pertaining to or affecting the skin. Dermatitis An inflammation of the skin. Designated Area An area which may be used for work with "select carcinogens, reproductive toxins, or substances which have a high degree of acute toxicity." A designated area may be the entire laboratory, an area of a laboratory, or a device such as a laboratory hood. A designated area shall be placarded to reflect the designated hazard. Dose The concentration of a substance and the time period during which the exposure occurs. The dose received links hazard and toxicity. Dyspnea Shortness of breath; difficult or labored breathing. Emergency Spills Accidental chemical discharges that present an immediate danger to personnel and/or the environment. Under these circumstances, leave the spill site immediately and send for help. Management of these spills is the responsibility of specially trained and equipped personnel. Contact the campus police at 911 for response. They will notify the appropriate persons/departments. (See Section 1.1 - "Chemical Spills") EPA The Environmental Protection Agency is the governmental agency responsible for administration of laws to control and/or reduce pollution of air, water, and land systems. EPA Number The number assigned to chemicals regulated by the Environmental Protection Agency (EPA). Erythema A reddening of the skin. Fires Class A Fires in ordinary combustible materials such as wood, cloth, paper, rubber, and many plastics. Class B Fires in flammable liquids, oils, greases, tars, oil-base paints, lacquers and flammable gases. Class C Fires that involve energized electrical equipment where the electrical conductivity of the extinguishing medium is of importance; when electrical equipment is de-energized, extinguishers for class A or B fires may be safely used. Class D Fires in combustible metals such as potassium, sodium, lithium, magnesium, titanium, sirconium. Flammable Any substance which may be classified as a flammable aerosol, flammable gas, flammable liquid or flammable solid. Flammable Aerosol An aerosol that, when tested by the method described in 16 CFR 1500.45, yields a flame protection exceeding 18 inches at full valve opening, or a flashback (a flame extending back to the valve) at any degree of valve opening. Flammable Gas A gas that, at ambient temperature and pressure, forms a flammable mixture with air at a concentration of 13 percent by volume or less; or a gas that, at ambient temperature and pressure, forms a range of flammable mixtures with air wider that 12 percent by volume, regardless of the lower limit. Flammable Liquid Any liquid having a flashpoint below 100oF (37.8oC), except any mixture having components with flashpoints of 100oF (37.8oC), or higher, the total volume of which make up 99 percent or more of the total volume of the mixture. Flammable Solid A solid, other than a blasting agent or explosive, that is liable to cause fires through friction, absorption of moisture, spontaneous chemical change, retained heat from processing, or which can be ignited readily, and when ignited burns so vigorously and persistently as to create a serious hazard. A chemical shall be considered a flammable solid if, when tested by the method described in 16 CFR 1500.44, it ignites and burns with a self-sustained flame at a rate greater than one-tenth of an inch per second along its major axis. Hazard The possibility that exposure to a substance will cause injury when a specific quantity is used under certain conditions. Health Hazard A substance for which there is statistically significant evidence based on at least one study conducted in accordance with established scientific principles that acute or chronic health effects may occur in exposed employees. This term includes carcinogens, toxic or highly toxic agents, reproductive toxins, irritants, corrosives, sensitizers, hepatotoxins, nephrotoxins, neurotoxins, agents which act on the hematopoietic systems, and agents which damage the lungs, skin, eyes, or mucous membranes. ICP Inductively-coupled argon spectrometers IDLH Immediately dangerous to life or health concentrations represent the maximum concentration from which one could escape within 30 minutes without a respirator and without experiencing any escape-impairing (e.g., severe eye irritation) or irreversible health effects. Ignitable A solid, liquid, or compressed gas that has a flashpoint of less 140oF. Ignitable material may be regulated by the EPA as a hazardous waste, as well. Incompatible The term applied to two substances to indicate that one material cannot be mixed with the other without the possibility of a dangerous reaction. Ingestion Taking a substance into the body through the mouth as food, drink, medicine, or unknowingly as on contaminated hands or cigarettes, etc. Inhalation The breathing in of an airborne substance that may be in the form of gases, fumes, mists, vapors, dusts, or aerosols. Inhibitor A substance that is added to another to prevent or slow down an unwanted reaction or change. Irritant A substance that produces an irritating effect when it contacts skin, eyes, nose, or respiratory system. LC50 See Lethal Concentration50. LD50 See Lethal Dose50. LEL See Lower Explosive Limit. Lethal Concentration50 The concentration of an air contaminant that will kill 50 percent of the test animals in a group during a single exposure. Lethal Dose50 The dose of a substance or chemical that will kill 50 percent of the test animals in a group within the first 30 days following exposure. LFL See Lower Explosive Limit. Lower Explosive Limit (Also known as Lower Flammable Limit.) The lowest concentration of a substance that will produce a fire or flash when an ignition source (flame, spark, etc.) is present. It is expressed in percent of vapor or gas in the air by volume. Below the LEL or LFL, the air/contaminant mixture is theoretically too "lean" to burn. (See also UEL.) Minor Spills Small chemical leaks that usually are detected early and present no immediate danger to personnel or the environment. These are spills that can be safely corrected with the advice of knowledgeable laboratory or supervisory personnel. MSDS Material Safety Data Sheet (See Section 9.3) Mutagen Anything that can cause a change (or mutation) in the genetic material of a living cell. Narcosis Stupor or unconsciousness caused by exposure to a chemical. NFPA The National Fire Protection Association is a voluntary membership organization whose aims are to promote and improve fire protection and prevention. NFPA has published several volumes of codes known as the National Fire Codes. NIH National Institute of Health NIOSH The National Institute for Occupational Safety and Health is a federal agency that among its various responsibilities trains occupational health and safety professionals, conducts research on health and safety concerns, and test and certifies respirators for work place use. Odor Threshold The minimum concentration of a substance in the air at which a majority of test subjects can detect and identify the substance's characteristic odor. OSHA The Occupational and Safety Health Administration is a federal or state agency under the Department of Labor that publishes and enforces safety and health regulations for most businesses and industries in the United States. OSU HAZCOMM OSU Environmental Health Services Department Hazard Communications Section OSU HAZMAT OSU Environmental Health Services Department Hazardous Materials Section Oxidizer A substance such as chlorate, permanganate, inorganic peroxide, nitrocarbonitrate, or a nitrate that yields oxygen readily to stimulate the combustion of organic matter. Oxygen Deficiency An atmosphere having less than the normal percentage of oxygen found in normal air. Normal air contains approximately 21% oxygen at sea level. PEL See Permissible Exposure Limit. Permissible Exposure Limit An exposure limit that is published and enforced by OSHA as a legal standard. PEL may be either a time-weighted-average (TWA) exposure limit (8 hour), a 15-minute short term exposure limit (STEL), or a ceiling (C). The PELs are found in Tables Z-1, Z-2, or Z-3 of 29 CFR 1910.100. This level of exposure is deemed to be the maximum safe concentration and is generally the same value as the threshold limit value (TLV). Personal Protective Equipment Any devices or clothing worn by the worker to protect against hazards in the environment. Examples are respirators, gloves, and chemical splash goggles. Physical Hazard A substance which is a compressed gas, explosive, flammable, organic peroxide, oxidizer, pyrophoric, unstable or water reactive. Polymerization A chemical reaction in which two or more small molecules combine to form larger molecules that contain repeating structural units of the original molecules. A hazardous polymerization is the above reaction with an uncontrolled release of energy. Reactivity A substance's susceptibility to undergoing a chemical reaction or change that may result in dangerous side effects, such as explosion, burning, and corrosive or toxic emissions. The conditions that cause the reaction, such as heat, other chemicals, and dropping, will usually be specified as "Conditions to Avoid" when a chemical's reactivity is discussed on a MSDS. Respirator A device which is designed to protect the wearer from inhaling harmful contaminants. Respiratory Hazard A particular concentration of an airborne contaminant that, when it enters the body by way of the respiratory system or by being breathed into the lungs, results in some bodily function impairment. Sensitizer A substance that may cause no reaction in a person during initial exposures, but afterwards, further exposures will cause an allergic response to the substance. Sharps Hypodermic needles, syringes, (with or without the attached needle), pasteur pipettes, scalpel blades, suture needles, blood vials, needles with attached tubing, and culture dishes (regardless of presence of infectious agents). Also included are other types of broken or unbroken glassware that were in contact with infectious agents, such as used slides and cover slips. Short Term Exposure Limit Represented as STEL or TLV-STEL, this is the maximum concentration to which workers can be exposed for a short period of time (15 minutes) for only four times throughout the day with at least one hour between exposures. "SKIN" This designation sometimes appears alongside a TLV or PEL. It refers to the possibility of absorption of the particular chemical through the skin and eyes. Thus, protection of large surface areas of skin should be considered to prevent skin absorption so that the TLV is not invalidated. STEL See Short Term Exposure Limit Synonym Another name by which the same chemical may be known. Systemic Spread throughout the body; affecting many or all body systems or organs; not localized in one spot or area. Teratogen An agent or substance that may cause physical defects in the developing embryo or fetus when a pregnant female is exposed to that substance. Threshold Limit Value Airborne concentrations of substances devised by the ACGIH that represents conditions under which it is believed that nearly all workers may be exposed day after day with no adverse effect. TLVs are advisory exposure guidelines, not legal standards, that are based on evidence from industrial experience, animal studies, or human studies when they exist. There are three different types of TLV's: Time Weighted Average (TLV-TWA), Short Term Exposure Limit (TLV-STEL) and Ceiling (TLV-C). (See also PEL.) Time Weighted Average (TLV-TWA, Threshold Limit Value-Time Weighted Average) The time weighted average airborne chemical concentration for a normal eight hour work day and a 40 hour work week to which nearly all workers may be repeatedly exposed, day after day, without adverse effect. TLV See Threshold Limit Value. Toxic Substances such as carcinogens, irritants, or poisonous gases, liquids, and solids which are irritating to or affect the health of humans. Toxicity The potential of a substance to exert a harmful effect on humans or animals and a description of the effect and the conditions or concentrations under which the effect takes place. Trade Name The commercial name or trademark by which a chemical is known. One chemical may have a variety of trade names depending on the manufacturers or distributors involved. TWA See Time Weighted Average. UEL See Upper Explosive Limit. UFL See Upper Explosive Limit. Unstable Liquid A liquid that, in its pure state or as commercially produced, will react vigorously in some hazardous way under shock conditions (i.e., dropping), certain temperatures, or pressures. Upper Explosive Limit Also known as Upper Flammable Limit. Is the highest concentration (expressed in percent of vapor or gas in the air by volume) of a substance that will burn or explode when an ignition source is present. Theoretically above this limit the mixture is said to be too "rich" to support combustion. The difference between the LEL and the UEL constitutes the flammable range or explosive range of a substance. (See also LEL.) Vapour The gaseous form of substances which are normally in the liquid or solid state (at normal room temperature and pressure). Water Reactive Substances that react violently when in contact with water. They can be either be flammable solids or corrosives.