Expert Panel for Cosmetic Ingredient Safety:
The Food and Drug Administration (FDA) permits resorcinol to be used in topical acne Over-The-Counter (OTC) drug products at concentrations of up to 2% when used in combination with sulfur at levels of 3-8%. Resorcinol is also permitted as active an ingredient in OTC topical analgesics and anorectal drugs. The safety of 2-methylresorcinol and resorcinol has been assessed by the Expert Panel for Cosmetic Ingredient Safety.
The Expert Panel evaluated the scientific data and concluded that 2-methylresorcinol and resorcinol were safe as cosmetic ingredients. In 2006, the Expert Panel considered available new data on 2-methylresorcinol and resorcinol and reaffirmed the above conclusion.
The Expert Panel reviewed data that showed no effects following long term dermal exposure to resorcinol and 2-methylresorcinol. Data indicated that resorcinol and 2-methylresorcinol were mild skin irritants and rare sensitizers. However, at the concentrations used in cosmetics and personal care products, these ingredients were not irritating, sensitizing, or photosensitizing when tested on human volunteers. Tests of these ingredients for mutagenicity and carcinogenicity were negative.
FDA: Link to Code of Federal Regulations and Federal Register for Resorcinol
More information about the safety of hair dyes.
Resorcinol is listed in Annex III (substance which cosmetic products must not contain except subject to the restrictions and conditions laid down) and may be used as an oxidizing coloring agent for hair dyeing at maximum concentrations of 1.25%, and in hair lotions and shampoos at a maximum concentration of 0.5%. Products containing resorcinol must be labeled “Contains resorcinol”. 2-methylresorcinol is also listed in Annex III of the Cosmetics Directive of the European Union and may be used in oxidizing and non-oxidizing hair dye products at a maximum concentration of 1.8%.
The Joint FAO/WHO Expert Committee on Food Additives concluded that there is no safety concern at current levels of intake of resorcinol when used as a flavoring agent.