preservative
DMDM Hydantoin
Watch if sensitive·Strong evidence
A preservative that works by slowly releasing small amounts of formaldehyde to control microbial growth. This makes it an effective preservative, but people with a known formaldehyde or fragrance-type sensitivity may develop irritation or an allergic reaction, especially with prolonged use of leave-on products.
Worth knowing
- Known contact sensitizer for some
- Can irritate, especially left on
- Restricted in the EU
EU rules cap free formaldehyde release and require a "contains formaldehyde" warning on the label once free formaldehyde exceeds 0.05%.
Gentler alternatives
Products with DMDM Hydantoin
References
Cosmetic information for general education, not medical advice. Concern is graded on cited evidence, never on hazard-score lists. See how we score.