New Hampshire Cosmetology Practice Exam

The requirement for a patch test is particularly associated with permanent hair color formulations. A patch test is essential because permanent hair dyes contain stronger chemicals, including ammonia and peroxide, which can cause allergic reactions in some individuals. By conducting a patch test, a small amount of the dye is applied to the skin, usually behind the ear or on the inside of the elbow, to observe any adverse reactions before applying it to the entire head. This helps ensure the safety of the client and avoid potential skin irritations or allergic responses.

While semi-permanent and temporary colors are generally considered safer options with fewer harsh chemicals, they may still cause reactions in some users. However, the regulations often do not mandate a patch test for these types of color formulations. It's important for cosmetologists to prioritize client safety, making the patch test a critical step specifically for permanent color applications.