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formaldehyde-releasing preservative

1,3-Bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione

CAS 6440-58-0
42

Safety score · 0–100

Moderate

Derived from EU CosIng regulatory status, PubChem hazard data and published research. How we score.

DMDM hydantoin is a formaldehyde-releasing preservative authorised in EU cosmetics up to 0.6%. It is effective but sensitises some users, hence the cautious orange rating.

Skin benefits

  • Broad-spectrum cosmetic preservative effective at low levels
  • EU Annex V approved up to 0.6% in finished cosmetics
  • Helps prevent microbial spoilage in water-containing products

Known concerns

  • Formaldehyde-releasing preservative; releases formaldehyde over time
  • Known contact allergen, especially in formaldehyde-sensitive users
  • Can cause skin irritation and serious eye irritation (H315, H319)
  • Restricted or banned by some retailers and brand free-from lists

References

EU

EU CosIng database

European Commission cosmetic ingredient registry: regulatory status, restrictions, authorised functions.

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This profile is for educational purposes and does not constitute medical advice. Regulatory status and scientific understanding evolve, so always read the physical product label and consult a healthcare professional for personal concerns.