What essential step should be taken before applying a chemical treatment to ensure safety?

Performing a patch test is an essential step before applying a chemical treatment to ensure safety. This procedure involves applying a small amount of the chemical product to the skin, usually behind the ear or on the inside of the elbow, and observing for any adverse reactions such as itching, redness, or swelling. Conducting a patch test is crucial because it helps identify potential allergies or sensitivities that a client may have to the ingredients in the chemical treatment.

This preventative measure protects both the client and the barber, as allergic reactions can lead to discomfort, serious health issues, or negative outcomes regarding the chemical service being performed. Ensuring that a client can tolerate the product before a full application is a standard practice that underlines the importance of safety in cosmetology and barbering.