Diazolidinyl Urea
يوريا ديازوليدينيل
Preservative (Annex V) · INCI: Diazolidinyl Urea · CAS: 78491-02-8
Permitted, but it releases formaldehyde - worth knowing if your skin reacts.
Why this verdict
Annex V #46 permitted preservative: max 0.5%.. Permitted within limits; formaldehyde-releaser/contact-allergen concern → caution.
What It Is
A formaldehyde-releasing preservative.
A formaldehyde RELEASER: it works by slowly releasing small amounts of formaldehyde. Formaldehyde itself is EU-banned (Annex II), but releasers stay permitted within limits. The EU just tightened the 'releases formaldehyde' warning threshold to 0.001% (from 0.05%, effective 15 Jul 2026). Relevant if you're formaldehyde-sensitive.
Evidence & Status
IARC Carcinogen Group
Not classified
EU Status
Annex V #46 permitted preservative - max 0.5%.
US · FDA Status
Preservative; CIR/SCCS-reviewed
Cosmetic Safety
EU concentration limit
Annex V #46: max 0.5%.
EU Annex status
Annex V (preservative)
Function
preservative
Halal Status: Halal
Synthetic; halal/vegan.
Worth Knowing
Primary Source
Evidence, not medical advice. You decide.
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