Pennsylvania Cosmetology Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

The purpose of a patch test before coloring hair is to check for allergies to hair dye. This test is crucial because hair dye contains a variety of chemicals, some of which can cause allergic reactions in sensitive individuals. By applying a small amount of the dye to a discreet area of the skin, typically behind the ear or on the forearm, a stylist can monitor the area for any adverse reactions such as redness, itching, or swelling over a 24 to 48-hour period. If no reaction occurs, it is generally safe to proceed with the hair coloring process.

The other options, while they relate to hair care in different ways, do not accurately describe the primary purpose of a patch test. Determining hair texture, assessing hair damage, and evaluating color choice are important aspects of hair treatment and care but are not specifically related to the allergy-checking function of a patch test. The risk of an allergic reaction makes patch testing a critical step in ensuring clients' safety when using chemical hair products.