New Hampshire Cosmetology Practice Exam 2026 - Free Cosmetology Practice Questions and Study Guide

A cosmetologist should recommend a patch test before any chemical service because this procedure is essential for ensuring client safety and preventing adverse skin reactions. Chemical services often involve strong substances that can lead to allergic reactions or sensitivity. By conducting a patch test, typically involving the application of a small amount of the product to a discreet area of skin, the cosmetologist can observe any negative reactions before applying the product on a larger scale.

Choosing to perform a patch test solely for dyeing services, as suggested by one of the options, would limit safety checks to only one type of chemical service. This does not account for other possible chemical treatments, such as perms or relaxers, that might also induce allergic reactions in some clients.

Similarly, while it's important to ensure that clients are not allergic to new grooming tools, the focus of a patch test primarily relates to chemical reactions, making the patch test less relevant in such scenarios. The key point is that a patch test is a precautionary measure that should be utilized broadly for any service that involves chemicals to maximize client safety.