Used as a preservative in cosmetics, especially shampoos, creams, lotions, rinses, bat products and eye make-up, as it inhibits bacteria, fungi and yeasts. It can form nitrosamine - which has been determined to form cancer in lab animals and also break down into formaldehyde. The Consumer Dictionary of Cosmetic Ingredients advises, if a product lists an ingredient with bronopol and another compound ending with -amine or -amide, don't purchase it.

Used in emollient creams, preshave lotions, after shave lotions and skin fresheners and perfumes as a preservative and to give a cool feeling to the skin. Local irritant which may cause contact dermatitis and is a central nervous system stimulant. It is readily absorbed through body tissues and can irritate eyes, nose, and throat can prompt dizziness, confusion nausea. Avoid inhaling vapors. On the Health Canada Cosmetic Ingredient Hot List.

Coal tar appears in many hair dyes and strong dandruff and psoriasis shampoos, but the FDA failed to ban it even though studies have linked it to cancer. Coal-tar chemicals are found in many "FD&C" or "D&C" colours used in makeup and hair dye. FD&C Blue 1 and FD&C Green 3 are possible carcinogenic, and impurities in other colours -- D&C Red 33, FD&C Yellow 5 and FD&C Yellow 6 -- have been shown to cause cancer when applied to the skin. Coal tar derivatives are used as a dye base for dark hair colouring. Coal tar is a known human carcinogen and some substances derived from it that are used in hair colouring have been linked to bladder cancer and non-Hodgkin's' lymphoma.

DEA is a strongly suspected as being a human carcinogen. These chemicals are also known to combine with nitrates to form cancer-causing nitrosamines - compounds shown to cause cancer in laboratory animals. If a product contains nitrites (used as a preservative or present as a contaminant not listed on labels) a chemical reaction can occur either during manufacturing or after a product is made. There is no way to know which products contain nitrosamines because government does not require manufacturers to disclose this information on the label. A 1997 study by the U.S. National Toxicology Program found that these compounds themselves might also be carcinogenic. Repeated skin application of DEA was found to cause liver and kidney damage in animals. The study also discovered that when absorbed through the skin, DEA accumulated in organs.