You probably know this one. Think back to grade ten biology class. That poor frog floating in a jar filled with. . . that’s right, formaldehyde. It is often used to keep frogs and other slimy things in jars because it is an excellent preservative. It is also commonly found in nail polish and hair straightening products. Most recently the US federal Occupational Safety and Health Administration (OSHA) investigated the use of formaldehyde in these poplar hair products.
Formaldehyde is a known human carcinogen; irritant to the skin and eyes, as well as lungs, kidney, stomach, and liver. It is also extremely toxic to the environment. . . I am sure our little amphibian friends can attest to that!
When formaldehyde-containing products are applied onto the skin and nails it can cause damage through absorption, however a more severe concern is the off-gassing that can occur particularly when the product is heated (e.g. hair straightening). According to the David Suzuki Foundation, most of the cancer research focuses on the risk caused by formaldehyde inhalation.
Warning: If you check product ingredient lists and do not see the presence of formaldehyde, you may also want to look for these other formaldehyde-releaseing preservatives:
Methylene glycol, Formalin, Methylene oxide, Paraform, Formic aldehyde, Methanal, Oxomethane, Oxymethylene, Timonacic acid, Thiazolidinecarboxylic acid