Arizona Cosmetology Practice Exam

Which chemical is commonly used in the process of permanent waving?

1. Hydrogen peroxide

2. Ammonium thioglycolate

3. Sodium hydroxide

4. Glyceryl monothioglycolate

The correct answer is: Ammonium thioglycolate

The process of permanent waving involves the use of chemicals that alter the structure of the hair to create curls or waves. Ammonium thioglycolate is the most commonly used chemical for this purpose because it effectively breaks down the disulfide bonds in the hair. These bonds are responsible for the hair's straightness and are reformed in a new shape once the hair is wrapped around a rod or another curling device. By utilizing ammonium thioglycolate, stylists can achieve lasting curls that hold their shape until new hair growth occurs. The effectiveness of this chemical is rooted in its ability to penetrate the hair shaft and create a lasting alteration in the hair's physical structure during the waving process. Other chemicals mentioned do serve significant roles in hair treatment, but they are not primarily used for permanent waving in the same capacity. For instance, hydrogen peroxide is typically used as a bleaching agent, sodium hydroxide serves as a strong relaxer for straightening hair, and glyceryl monothioglycolate is more commonly associated with softer waving processes or as a gentle alternative in some perm formulas. Understanding these differences is crucial for effective and safe hair treatments in cosmetology.