Empire Beauty School Chemical Texturizing Practice Test

Sodium hydroxide is recognized as a strong alkaline ingredient commonly used in relaxers due to its effective ability to break down the disulfide bonds in curly or textured hair. This strong alkalinity enables it to penetrate the hair shaft and alter the hair structure, resulting in straightened hair when used as part of a chemical relaxer.

The choice of sodium hydroxide is also linked to its potency, which allows stylists to achieve desired straightening results effectively. It's important to note that because of its strength, the application of sodium hydroxide-based relaxers requires careful handling to avoid potential damage or irritation to the scalp and hair.

In contrast, other options, while related to chemistry or hair care, do not serve the same primary purpose in relaxers. For instance, ammonium thioglycolate is often associated with softer waves or curls rather than strong straightening, sodium bicarbonate is a mild alkaline and often used for different purposes, and calcium carbonate is more commonly used as a buffering agent and does not have the strong alkaline properties needed for effective hair relaxing.