Somebody is after Procter and Gamble and it is hard to know why. Years ago there was the allegation that the company’s corporate logo hid a picture of the devil, then sodium lauryl sulfate, a common ingredient in detergents was acclaimed to be the chemical from hell by rapidly circulating e-mails, and Procter and Gamble’s deodorizer Febreze was accused of killing pets because it contained “toxic” zinc chloride. This is all nonsense. Now comes a new scare. This time the target of the hate mail is the “Swiffer WetJet,” a rather nifty product. It’s a device that allows a pre-moistened cloth to be attached to a mop and affords an easy way to clean stains on floors. The circulating e-mail claims that the solvent used on the cloth is dangerous to pets and tells of a dog and two cats that perished just by walking on a freshly mopped floor.
I’m going to come to the aid of Procter and Gamble. Not because I’m a great supporter of giant corporations but because I’m a great supporter of good science. And the allegations against the Swiffer WetJet are just plain bad science. The e-mail does not document where the supposed death of the dog occurred, so it is not possible to check out the story. But even if a dog somewhere did die after walking on a mopped floor, one cannot legitimately conclude that chemicals left on the floor were responsible. The events may have been totally unrelated. According to the story, an autopsy was performed on the dead animal and liver failure was diagnosed. Then the author points a finger at the solvent, propylene glycol n-propyl ether, used in the Swiffer product. He suggests that this is “one molecule away from antifreeze” which is known to be deadly to animals.
First of all the antifreeze that really is dangerous to dogs is ethylene glycol. Indeed, dogs have been poisoned by licking up spills when their masters were changing the antifreeze in their cars’ radiator. Ethylene glycol, though, causes kidney and not liver failure. But that isn’t even the point. The statement of propylene glycol n-propyl ether being one molecule away from antifreeze is absurd. This is where a little learning becomes a truly dangerous thing. Propylene glycol, which is also used as antifreeze is close in structure to ethylene glycol. It isn’t one molecule away, it just has an extra carbon and three hydrogens. That difference actually makes it into a safer product! Propylene glycol has replaced ethylene glycol in many products where toxicity is an issue. But we are still not done. Swiffer doesn’t contain propylene glycol, it contains propylene glycol n-propyl ether, a completely different substance with very low toxicity. Furthermore, the solvent on the mop is mostly water with the propylene glycol n-propyl ether being present to a maximum of four percent. And finally, the solvent is reabsorbed into the mop, so essentially nothing is left on the floor. The only thing left after using a Swiffer WetJet is the Internet nonsense that is going around. I wish we could Swiff that away as easily as the Swiffer Jet swiffs away stains on floors.