Calcium thioglycolate (inci)

Calcium thioglycolate, the calcium salt of thioglycolic acid, is a substance used in cosmetic products as depilatory agent. Furthermore, the substance acts as a reducing agent and thus changes the chemical nature of a product.

According to the German Cosmetic Decree, depilatories may contain up to 5% thioglycolic acid. Thioglycolic acid causes the desired depilation effect.

The Federal Institute for Risk Assessment (BfR) concludes that the widespread application of thioglycolic acid or its salts (thioglycolates) on the skin may cause undesirable side effects (ADR). Slight to moderate skin irritations may occur. Allergic skin reactions may also occur.

According to the BfR, there is no risk of irritation of the respiratory tract through inhalation of thioglycolic acid.

Consumers should only use the products in accordance with these instructions, i.e. they should not be applied to large areas and mucous membrane contact should be avoided. In depilatories the calcium, potassium and sodium salts of thioglycolic acid as well as the thioglycolic acid itself are used; according to the findings of the Cosmetics Commission at the BfR in Germany mainly calcium thioglycolates seem to be used. Thioglycolates act by reducing the cysteine disulfide compounds in the keratin of the hair cortex. This destroys the hair structure.

Health assessment of thioglycolic acid and its salts in depilatories(BfR statement 027/2011 of 31 May 2011)

Burnett CL et al (2009) Cosmetic Ingredient Review Expert Panel, Andersen FA. (2009) Final amended report on the safety assessment of Ammonium Thioglycolates, Butyl Thioglycolates, Calcium Thioglycolates, Ethanolamine Thioglycolates, Ethyl Thioglycolates, Glyceryl Thioglycolates, Isooctyl Thioglycolates, Isopropyl Thioglycolates, Magnesium Thioglycolates, Methyl Thioglycolates, Potassium Thioglycolates, Sodium Thioglycolates, and Thioglycolic Acid. Int J Toxicol 28 (4 Suppl):68-133.