Hair dyes are mutagenic: identification of a variety of mutagenic ingredients

Abstract

Previously, a sensitive bacterial test for detecting carcinogens as mutagens has been described. It was shown that 89% (150/169) of commercial oxidative type (hydrogen peroxide) hair dye formulations are mutagenic in this test. Of the 18 components of these hair dyes, nine show various degrees of mutagenicity: 2,4 diaminoanisole, 4 nitro o phenylenediamine, 2 nitro p phenylenediamine, 2,5 diaminoanisole, 2 amino 5 nitrophenol, m phenylenediamine, o phenylenediamine, 2 amino 4 nitrophenol, and 2,5 diaminotoluene. Three hair dye components (p phenylenediamine, 2,5 diaminotoluene, and 2,5 diaminoanisole) become strongly mutagenic after oxidation by H2O2; the mutagenic product of p phenylenediamine is identified as the known trimer, Bandrowski's base. 2,4 Diaminotoluene, a hair dye component until recently, is also shown to be mutagenic: this compound has been shown to be a carcinogen in rats, and is used in large amounts in the polyurethane foam industry. About 20,000,000 people (mostly women) dye their hair in the U.S. and the hazard could be considerable if these chemicals are actually mutagenic and carcinogenic in humans.