5: Final Report on the Safety Assessment of 2-Methylresorcinol and Resorcinol

Abstract

2-Methylresorcinol and Resorcinol are most frequently used in cosmetic hair dye formulations at concentrations between 1 and 5%. The results of cutaneous and oral feeding studies have indicated that both 2-Methylresorcinol and resorcinol are readily absorbed by rodents and are rapidly eliminated. Acute oral toxicity studies indicate that 2-Methylresorcinol is moderately toxic and Resorcinol is slightly to moderately toxic. Subchronic feeding and dermal studies of bothingredients produced no significant effects. A chronic dermal study was uneventful. Significant skin effects were observed in mice, but not in rabbits, following dermal application of Resorcinol at 5%. A 10% Resorcinol solution was not irritating to guinea pigs. A 2.5% 2-Methylresorcinol solution was classified as a primary irritant in rabbits, but 10% 2-Methylresorcinol was not irritating to guinea pigs. 2-Methylresorcinol was not an ocular irritant at 2.5%, but irritation was produced at 5% concentration in unwashed rabbit eyes. Neither 2-Methylresorcinol at 5% nor Resorcinol at 3% produced sensitization in guinea pigs. 2-Methylresorcinol was not photoallergenic to guinea pigs but was a sensitizer at 10%. Resorcinol was not photoallergenic to guinea pigs but was a sensitizer at 10%. Resorcinol and 2-Methylresorcinol were nonmutagenic in microbial and tissue culture assays for mutagenicity. Topically applied hair dyes containing 2-Methylresorcinol and Resorcinol were negative for carcinogenicity. Resorcinol showed no cocarcinogenic potential when tested on mice and rats. 2-Methylresorcinol at 3% concentration produced no evidence of irritation or sensitization in human subjects. Resorcinol was a mild skin irritant and rare sensitizer in clinical testing, but not when tested on nonclinical groups. On the basis of the available animal and clinical data, it is concluded that 2-Methylresorcinol and Resorcinol are safe as cosmeticingredients in the present practices of use and concentrations.

Freezing Weakens the Barrier Function of Reconstructed Human Epidermis as Evidenced by Raman Spectroscopy and Percutaneous Permeation

“…As a permeant we used resorcinol, a common ingredient in cosmetic products. In hair dyes it is used as a coupler to primary intermediates such as p-phenylenediamine to produce the final hair color [44,45], often in concentrations of 1 to 5% [46]. In skin care, it is an ingredient of anti-acne formulations and peels [47].…”