Hair straightening products with formaldehyde are harmful
The Federal Institute for Risk Assessment (BfR) advises against the use of hair straightening products which contain formaldehyde in partly high concentrations. Products containing free formaldehyde in concentrations of 1.7 to 1.8 percent had attracted the attention of the surveillance authorities in Baden-Württemberg. "These concentrations can be harmful", said BfR President Professor Dr. Dr. Andreas Hensel. Formaldehyde has a strong irritating effect on the eyes, the skin and the mucous membranes. Moreover, the substance can cause allergies and has been classified by BfR as a human carcinogen. Within the EU formaldehyde is not approved for use in hair straightening products. However, consumers and hairdressers appear to source foreign products by direct import or via the Internet, without knowing that they can be harmful.
Formaldehyde can cause cancer in the nasopharynx. Recently science has also discussed a possible link between formaldehyde and the occurrence of myeloid leukaemia. Formaldehyde is known for causing allergic reactions of the respiratory tract and the skin up to a life-threatening anaphylactic shock. Moreover, it has a strong irritating effect on the eyes, the skin and the mucous membranes. For formaldehyde in indoor air, BfR has derived a safe threshold value of 0.1 ppm.
Within the EU formaldehyde is only approved as an active ingredient in nail hardeners in concentrations of up to 5 percent and as a preservative agent in cosmetics only up to a concentration of 0.2 percent; from 0.05 percent labelling is prescribed. In hair straightening products examined by the surveillance authorities in Baden-Württemberg, 1.7 to 1.8 percent of formaldehyde were detected. The use of hair straightening products with these concentrations involves a health risk for users.
BfR recommends to the competent authorities of the federal Laender to take corresponding measures and inspect, for instance, hairdressing salons in view of formaldehyde-containing hair straightening products. BfR urgently advises consumers not to use such products at home. They appear to be available via Internet mail order.
Hair straightening products are used to permanently straighten naturally frizzy hair. The product is applied on to the hair, and after a reaction time of 30 minutes, the hair is straightened using a 230 °C hot styling iron. If the hair straightening product contains formaldehyde, the latter is inhaled together with the developing vapours by the hairdresser and the customer or private user. The release of formaldehyde from the examined products is so high that irritations of the skin, mucous membrane, eyes and respiratory tract, allergic reactions of the skin and other damage to health are possible.
Formaldehyde in hair straightening products serves for the new cross-linking of the keratins in the hair broken by the heat. A curly hair structure is straightened in this way.