Abstract
N,N-Bis(Hydroxyethyl-p-Phenylenediamine Sulfate is used in cosmetic hair dye and color formulations at concentrations ≥ 5%.
The oral LD50 of N,N-Bis(Hydroxyethyl-p-Phenylenediamine Sulfate for rats was 264 mg/kg. Rats fed NNPD at ≥ 0.30% for 13 weeks had decreased body weights, feed consumption, serum iron concentrations, and reduced pituitary weights. The results from subchronic dermal studies at 1.0% were unremarkable.
In sensitization studies using guinea pigs, 3% NNPD induced delayed hypersensitivity. A 2% solution produced a strong contact allergic, but not a photoallergenic, response. A repeated insulted patch test in 104 humans produced definite sensitization in one subject and possible sensitization in another.
Neither teratogenic nor embryotoxic effects were produced in rats by dermal administration of 1.0% NNPD or by administration of 0.3% NNPD in the diet. When assayed in rats, NNPD was neither hepatocarcinogenic nor a promoter of liver cancer.
On the basis of the data presented in this report, and the placement of precautionary labeling on cosmetic hair dye products containing coal tar ingredients, it is concluded that N,N-Bis(Hydroxyethyl)-p-Phenylenediamine Sulfate is safe as a cosmetic ingredient in the present practices of use and concentration.