What must a cosmetologist do before performing a chemical service?

Before performing a chemical service, it is essential for a cosmetologist to conduct a consultation and patch test. This step is crucial for several reasons. First, the consultation allows the cosmetologist to gather important information about the client's hair history, current condition, and any potential allergies or sensitivities the client may have. This information is vital for selecting the appropriate products and techniques for the service while ensuring the safety and satisfaction of the client.

A patch test, which involves applying a small amount of the chemical product to a discreet area of the skin (often behind the ear or on the inner elbow), is conducted to check for any adverse reactions. This precaution helps identify any allergy or sensitivity a client may have to the chemicals in the product, thereby preventing potential irritation or harm during the actual service.

In contrast, administering a scalp treatment, applying a leave-in conditioner, or evaluating hair length and thickness may be important components of a comprehensive hair care strategy, but they do not assess the client's skin sensitivity or overall readiness for a chemical service. These actions might be relevant post-consultation, but they are not prerequisites prior to starting a chemical procedure.