High concernPreservative
Diazolidinyl Urea
Formaldehyde releaserKnown carcinogenAllergen
What it is
A urea-derived heterocyclic preservative that decomposes to release formaldehyde.
What it does
Broad-spectrum antimicrobial for water-based cosmetics, often combined with parabens or phenoxyethanol.
Why it’s a concern
Among the most common formaldehyde releasers associated with allergic contact dermatitis in North American Contact Dermatitis Group patch-test data. The release of formaldehyde, a Group 1 carcinogen, is the core concern even if concentrations stay within regulatory limits.
Also known as
germall II
CAS numbers
78491-02-8
Commonly found in
lotionshampoomakeupbaby wipes
Safer alternatives
- sodium benzoate
- potassium sorbate
- phenoxyethanol at low levels
Related chemical families
Sources
- NACDG Patch Test Data 2019-2020