The use of formaldehyde and methylene glycol in hair straightening products involving heat is unsafe, the Cosmetic Ingredient Review Expert Panel determined after an intense discussion of the issue during its June 28 meeting in Washington D.C.

The National Toxicology Program has included formaldehyde on its list of known human carcinogens, potentially adding to the controversy surrounding the safety of the ingredient and its use in hair-straightening products.

Women’s Voices for the Earth continues to call attention to cosmetic ingredients’ potential health impacts on users including salon workers, while pushing the Cosmetic Ingredient Review to consider a wider variety of safety information in its assessment work.