Which type of hair color requires a patch test before use?

Semi-permanent and permanent hair color require a patch test before use because they contain ingredients that can cause allergic reactions in some individuals. Conducting a patch test helps identify any potential sensitivities or allergies to the chemicals in these formulations. This test is typically performed by applying a small amount of the hair color product to an inconspicuous area of skin, usually behind the ear or on the inner elbow, and observing for any adverse reactions over 24 to 48 hours.

Temporary hair color, on the other hand, generally uses less potent chemicals and does not require a patch test for safety reasons since it is less likely to cause a severe allergic reaction. Natural hair color products, which may use plant-based dyes, also tend to be gentler on the skin. While some individuals may still experience reactions to any hair color product, the more significant concern lies with the semi-permanent and permanent options due to their stronger chemical compositions.