7 Final Report on the Safety Assessment of Diazolidinyl Urea

Abstract

Diazolidinyl Urea is a heterocyclic-substituted urea used as a preservative in a variety of cosmetic products at a normal product use concentration of 0.2 to 0.4%, up to a maximum of 1.0%. Diazolidinyl Urea was slightly toxic to rats in acute oral studies but was relatively non-toxic in subchronic studies. At 5%, Diazolidinyl Urea was not an ocular or skin irritant in rabbits. In three studies using a maximization procedure, Diazolidinyl Urea was a mild sensitizer in guinea pigs, but was not a sensitizer in a fourth study in which a nonmaximization procedure was used. Diazolidinyl Urea was nonmutagenic when tested in the Ames test, or in the micronucleus assay. At concentrations up to 0.4%, Diazolidinyl Urea was a mild cumulative skin irritant in humans. In was not a sensitizer in an RIPT study on nonpatient volunteers. Fifty-seven of 2385 patients had allergic reactions to 1.0% Diazolidinyl Urea. It was not a photosensitizer at 0.25%. This report notes that Diazolidinyl Urea is a formaldehyde releaser. It has been previously concluded that the use of formaldehyde in cosmetic products is safe to the great majority of consumers. There is no indication that the use of Diazolidinyl Urea as used in cosmetic products would release formaldehyde at concentrations which would exceed the limits recommended for formaldehyde. The report concludes that Diazolidinyl Urea may be safely used in cosmetic products at the minimum effective concentration, not to exceed 0.5%.