NOCTI Cosmetology Practice Exam 2025 - Free Cosmetology Practice Questions and Study Guide

The primary chemical component found in the solution that processes a chemical permanent wave is ammonium thioglycolate. This substance serves as a reducing agent that breaks down the disulfide bonds in the hair's keratin structure, allowing it to be reshaped and set into curls or waves. Because of its ability to soften the hair and alter its protein structure, ammonium thioglycolate is widely used in products specifically designed for perming hair.

Other chemicals mentioned, such as ammonium sulfite, sodium hydroxide, and calcium carbonate, have distinct roles in hair treatments but are not the primary agents in creating permanent waves. Ammonium sulfite is mostly used in certain formulations of perms but does not possess the same effectiveness as thioglycolate for long-lasting results. Sodium hydroxide is more commonly associated with chemical relaxers, as it straightens hair rather than creating curls. Calcium carbonate is not typically used in hair processing solutions, focusing instead on a range of other applications.