Final Report on the Safety Assessment of Phenyl Methyl Pyrazolone

Phenyl Methyl Pyrazolone (PMP) is a heterocyclic amine that is used in hair colorants. The phenylhydrazine content in PMP is below the limit of detection. Phenyl Methyl Pyrazolone was slightly toxic to rats, with an oral LD 50 of 3.5 g/kg. Feeding rats and mice with PMP-treated feed for 7 weeks was uneventful. A compound containing 500 mg/kg of PMP was, at most, a mild ocular irritant. Phenyl Methyl Pyrazolone was slightly irritating to rabbit skin when tested under occlusive patches. It did not produce a sensitization reaction in guinea pigs. Phenyl Methyl Pyrazolone was nonmutagenic in two assays and noncarcinogenic in oral feeding studies. On the basis of the available data presented in this report, it is concluded that Phenyl Methyl Pyrazolone is safe for use as a cosmetic ingredient in the present practices of use and concentration.