What is a primary function of a patch test in hair coloring?

A primary function of a patch test in hair coloring is to check for allergies. This procedure helps to identify any potential allergic reactions that a client may have to the chemicals found in hair dye. By applying a small amount of the dye on a discreet area of skin, typically behind the ear or on the inner arm, a stylist can monitor for any adverse reactions like redness, itching, or swelling over a specified period. This is crucial for client safety, as allergic reactions can lead to serious skin conditions if the product is applied to the hair without prior testing.

Determining hair texture, deciding on a color choice, or assessing hair condition are all important aspects of hair coloring but they do not specifically relate to the safety check that a patch test provides regarding allergies.