New Jersey Cosmetology and Hairstyling Practice Exam

What type of chemical is typically used in a hair relaxer?

1. Hydrogen peroxide

2. Glycolic acid

3. Sodium hydroxide or ammonium thioglycolate

4. Calcium hydroxide

The correct answer is: Sodium hydroxide or ammonium thioglycolate

Hair relaxers are specifically designed to alter the structure of curly or textured hair, making it straighter and more manageable. The two primary chemicals used in hair relaxers are sodium hydroxide and ammonium thioglycolate. Sodium hydroxide is a strong alkali that works by breaking the disulfide bonds in the hair’s protein structure. This allows the hair to be reshaped and straightened. Ammonium thioglycolate, on the other hand, is a milder alternative that also breaks disulfide bonds but does so in a way that is less harsh on the hair. Understanding the function of these chemicals is crucial for cosmetologists, as they need to apply these products safely and effectively. They must also take precautions to protect the scalp and skin from potential irritation caused by these potent ingredients. Other chemical options, such as hydrogen peroxide, glycolic acid, or calcium hydroxide, do not serve the same purpose in hair straightening and are not used in relaxers for this specific function.