23 citations,
June 2014 in “International Journal of Cosmetic Science” Glyoxylic acid is a safer alternative to formaldehyde for hair straightening and effectively changes hair structure.
15 citations,
July 2002 in “Australasian Journal of Dermatology” Two plywood factory workers developed contact dermatitis from phenol-formaldehyde resin, a known allergen.
40 citations,
June 2013 in “Journal of cosmetic dermatology” Brazilian keratin treatments can straighten hair but may contain harmful formaldehyde.
13 citations,
March 2017 in “Skin Research and Technology” Formaldehyde damages curly hair more than glyoxylic acid.
2 citations,
January 2019 in “Applied clinical research, clinical trials and regulatory affairs” Different countries have regulations to ensure the safety of hair care products, with some recalling hair straighteners due to high formaldehyde.