Which type of color application necessitates a patch test?

Chemical hair color requires a patch test due to the potential for allergic reactions. These products can contain stronger, more permanent ingredients that penetrate the hair shaft and have a greater likelihood of causing irritation or an allergic response on the scalp or skin. A patch test, typically conducted 24 to 48 hours before application, involves applying a small amount of the dye to a discreet area of skin to observe any adverse reactions. This precaution ensures the safety of the client, as allergic reactions can range from mild irritation to severe skin reactions.

Temporary hair color, shampoo color, and hair gloss are typically formulated to be milder and non-permanent, which usually do not necessitate a patch test. These types of colors are designed for quick application and often wash out easily, reducing the risk of a significant allergic reaction. However, it is always advisable to do a patch test if the client is unsure about their skin's sensitivity or their previous experiences with hair color to ensure maximum safety.