Glyceryl thioglycolate is the essential ingredient in “acid” permanent hair waving solution, mainly used in hairdressing salons. It is also used in depilatories (hair removers) and in hair straighteners.
Glyceryl thioglycolate can be avoided by not using permanent hair-waving solutions that contain this chemical. These solutions are found only in salons in the United States and usually referred to as acid or hot permanents. These permanents can be identified because packages usually contain three bottles or containers. There is no cross-reactivity with ammonium thioglycolate, the active ingredients in alkaline permanents. Alkaline permanent wave preparations contain only two bottles or containers.
Salon labeling, which is voluntarily being introduced in the United States, should help hairdressers and clients to avoid Glyceryl thioglycolate. Hair that has been permed with substance may have persistence of allergen for at least three months. This can cause long-lasting dermatitis in clients or beauticians. Glyceryl thioglycolate easily penetrates through many rubber and vinyl gloves, which makes it difficult to impossible for beauticians to continue permanent hair waving with this allergen.