What common ingredient can cause reactions in chemical depilatories?

Calcium thioglycolate is commonly used in chemical depilatories due to its effectiveness in breaking down the protein structure of hair, which allows for its removal. However, it can also lead to chemical irritation or allergic reactions in some individuals, particularly if used improperly or on sensitive skin.

This reactivity is due to its alkaline properties and the presence of sulfhydryl groups, which can disrupt the natural acidity and protective barrier of the skin. Therefore, users are advised to perform a patch test prior to full application to ensure they do not have a sensitivity or adverse reaction to the ingredient.

In contrast, while other ingredients listed may have their own specific uses or benefits, they are not as commonly associated with skin reactions in the context of chemical depilatories as calcium thioglycolate is.