Formaldehyde is a naturally occurring chemical. It can be found in our bodies as well as in many of the products that we use everyday. In the early days of food mass production, formaldehyde was used as a preservative. Because is is a preservative, formaldehyde is also used in embalming.
It can now be found in glues and ink that is used to print books, magazines and money. Formaldehyde is used to make different kinds of plastic. Some of these plastics are used to make prosthetic limbs, pacemakers and artificial heart valves.
Formaldehyde-based materials are also used to produce engine and transmission parts and paint. If you own a pair of slacks or a dress shirt that was advertised as being "wrinkle-free", then the fabric used to make that garment was most likely treated with formaldehyde. The formaldehyde helps the dyes in the clothes resist bleeding and enables the material to resist wrinkling.
Because of its antimicrobial qualities, formaldehyde is used to create a number of vaccines for humans. These vaccines help prevent a number of illnesses like Polio, Influenza, Hepatitis A, Hepatitis B and Anthrax, just to name a few.