Expert Panel for Cosmetic Ingredient Safety:
The safety of 4-chlororesorcinol has been assessed by the Expert Panel for Cosmetic Ingredient Safety. The Expert Panel evaluated the scientific data and concluded that 4-chlororesorcinol was safe in hair dye formulations. In 2011, as part of the scheduled re-evaluation of ingredients, the Expert Panel considered available new data on 4-chlororesorcinol and reaffirmed the above conclusion.
The Expert Panel concluded that the scientific data suggested that 4-chlororesorcinol can be safely used in hair dye products. Sub chronic dermal exposure to a hair dye product containing 2% 4-chlororesorcinol produced no evidence of compound-induced toxicity. At the same concentration, no development effects, no evidence of reproductive toxicity, and no carcinogenic effects were seen following dermal exposure. Likewise, 4-chlororesorcinol was not mutagenic in either a micronucleus or in bacteria, nor did it induce aneuploidy in fungus cells. A 2.5% solution was not a dermal irritant or an ocular irritant.
More information about the safety of hair dyes.
4-Chlororesorcinol is permitted for use in oxidative hair dyes in the European Union at a maximum concentration of 2.5%. See Annex III for more information about the use of this ingredient in hair dyes in Europe.