What type of reaction can occur from a chemical hair treatment?

Chemical hair treatments involve various substances that can alter the hair’s structure, which can lead to significant changes in its texture, color, and overall health. The correct choice highlights that allergic reactions or chemical burns may occur as a result of these treatments. This is particularly important because many chemical processes—such as perming, relaxing, or coloring—use potent chemicals that can irritate the skin or cause allergic responses in some individuals.

When a client undergoes a chemical treatment, the formulations applied may contain ingredients that are allergens or may induce sensitivity in some people. If a patch test is not done prior to the treatment, it can lead to unforeseen adverse reactions, such as rashes or burns on the scalp or skin. Consequently, it's crucial for cosmetologists to adhere to safety protocols, such as conducting patch tests and following application guidelines, to minimize these risks.

The other options describe potential issues that can arise with hair but are not direct reactions to the chemicals used in treatments. For example, color fading is often a natural occurrence over time and not specifically an immediate reaction to a chemical treatment. Similarly, split ends and frizz can result from a variety of factors, including hair damage or environmental conditions, rather than being direct consequences of chemical application.