N,N''-Methylenebis[N'-[3-(hydroxymethyl)-2,5-dioxoimidazolidin-4-yl]urea]

About N,N''-Methylenebis[N'-[3-(hydroxymethyl)-2,5-dioxoimidazolidin-4-yl]urea]

A formaldehyde-releasing preservative effective against bacteria and yeast, permitted in cosmetics up to 0.6% but associated with contact allergy and sensitisation reactions.

Detailed Analysis

Commonly known as diazolidinyl urea, this compound releases formaldehyde on degradation and carries EU hazard statements H317 (skin sensitisation), H315 (skin irritation), and H319 (eye irritation). The EU Cosmetics Regulation permits its use as a preservative with a maximum concentration of 0.6% in ready-to-use preparations, and it must be declared in the ingredient list when present above threshold. Consumers with formaldehyde sensitivity should exercise caution with products containing this preservative.

Skin Benefits

• ✓ Effective broad-spectrum antimicrobial preservative extending product shelf life
• ✓ Provides protection against bacterial and fungal contamination in water-based formulations

Known Concerns

• ⚠ Formaldehyde releaser — risk of contact allergy and sensitisation (H317)
• ⚠ Skin and eye irritant (H315, H319)
• ⚠ Not suitable for consumers with known formaldehyde sensitivity
• ⚠ Can cause reactions in sensitised individuals even at permitted concentrations

References