November 15, 1996


Preserved cats or frogs, anatomists, pathologists and new rugs all smell like formaldehyde.

The worst part about formaldehyde is that if you walk into a room that has a lot of it in the air, the odor will almost knock you over; your eyes will burn and water, your nose will run and you will get out of there quickly. That, as I will explain, is also the best part about formaldehyde.

Unlike things like x-rays, that can do you a lot of damage without your being aware of it, when formaldehyde is around you know it.

When I was starting an ultra-clean mouse colony, which was to be started with germfree mice, I had to sterilize a whole room. There were several substances available to me: ethylene oxide, which is a deadly odorless and colorless gas; peracetic acid, a liquid which sterilizes whatever it touches and then degrades to acetic acid (vinegar); and formaldehyde gas. I chose the formaldehyde because not only was it cheap, but I could be sure that when it was gone, it was really gone. If there was formaldehyde in a room, my nose or my eyes would detect it immediately.

Formaldehyde is a very useful chemical. It is used to fix dyes(make them permanent) in textiles and carpet. When I go into a fabric store my eyes start to water. That's because of the formaldehyde. Some of the problems that people have when they get new carpets also relate to formaldehyde. Give it some time to air out and it goes away. The gas is very active chemically and it soon clears out of the atmosphere by combining with things in much the same way as free hydrogen or chlorine does.

It is used by anatomists and pathologists to "fix" tissue. It essentially pickles cells by combining with the protein. If you put some egg white in a water solution of formaldehyde, it will turn white and solid as if it had been boiled -but it would taste awful.

The Ames test for carcinogenicity (the ability to cause cancer) tests whether a chemical will cause genes to mutate in bacteria. Most mutagens(mutation causer) have also turned out to be a carcinogens. When formaldehyde was tested, it turned out to be a mutagen. We would therefore expect that people who were exposed to formaldehyde over a long period of time should have a higher incidence of cancer. So epidemiologists looked at groups of people who virtually live in a formaldehyde-filled atmosphere. They found absolutely nothing; no increase in cancer. Animals were kept in an atmosphere with lots of formaldehyde, which failed to produce cancer. Finally, one scientist managed to produce cancer of the urinary bladder in rats by injecting formaldehyde directly into the bladder. I asked him why formaldehyde didn't cause cancer in man. He replied that he thought that no human being could tolerate enough formaldehyde to produce a cancer.

Formaldehyde is a unique substance that is a mutagen and carcinogen, that doesn't cause cancer in man because it's such nasty stuff. Because of its chemical behavior, it usually doesn't get into the inside of cells because it will react with proteins before it has a chance to penetrate a cell.

The carcinogens that are the the most dangerous are those which we aren't aware of. That's what makes X-ray and other forms of ionizing radiation so dangerous. Things that you can see, feel or smell are easy to avoid.

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