DMDM hydantoin is an
antimicrobial formaldehyde releaser preservative with the trade name Glydant. DMDM hydantoin is an
organic compound belonging to a class of compounds known as
hydantoins. It is used in the
cosmetics industry and found in products like
shampoos,
hair conditioners, hair gels and skin care products.
[1][2]
DMDM hydantoin works as a preservative because the released
formaldehyde makes the environment less favorable to the
microorganisms.
A study found "An increase in the use of DMDM hydantoin in cosmetic products will also inevitably increase the risk of cosmetic dermatitis in consumers allergic to formaldehyde."
[3] DMDM hydantoin may cause allergic contact dermatitis to the product itself, cross-react with other formaldehyde releasing compounds or due to the formaldehyde released.