Idaho Barber Licensure Practice Exam

What is the primary ingredient in most hair relaxers?

1. Calcium carbonate

2. Glycerin

3. Sodium hydroxide

4. Ammonium thioglycolate

The correct answer is: Sodium hydroxide

The primary ingredient in most hair relaxers is sodium hydroxide. This chemical compound is classified as a strong alkaline substance that works by breaking down the disulfide bonds in the hair's structure, effectively allowing the hair to be reshaped. When applied to the hair, it raises the pH level, which softens the hair and makes it more malleable, facilitating the straightening process. Sodium hydroxide is particularly popular in chemical relaxers designed for textured or curly hair as it provides a lasting straightening effect. It is important for practitioners to understand the implications of working with sodium hydroxide, including the need for proper application techniques and aftercare to mitigate potential damage to the hair and scalp. While other ingredients mentioned may also be present in various formulations, they serve different functions. For example, ammonium thioglycolate is commonly used in perm solutions and some hair straighteners but is not the primary ingredient in traditional relaxers. Glycerin serves as a humectant, helping to retain moisture, and calcium carbonate might be used for various other applications but not as a primary relaxer ingredient. Understanding these components helps barbers provide effective treatments while ensuring client safety and satisfaction.