National Occupational Competency Testing Institute (NOCTI) Cosmetology Practice Exam

What are the two general classifications of hair relaxers?

1. Ammonium thioglycolate and calcium

2. Ammonium thioglycolate and sodium hydroxide

3. Hydrogen peroxide and sodium hydroxide

4. Glyceryl and calcium hydroxide

The correct answer is: Ammonium thioglycolate and sodium hydroxide

The correct choice identifies the two main types of hair relaxers as ammonium thioglycolate and sodium hydroxide. Ammonium thioglycolate is a type of relaxer that works through a chemical reaction to break down the disulfide bonds in the hair, effectively loosening its structure and making it more manageable for styling. This relaxer is generally milder and is often suitable for finer hair types or for those seeking a softer wave or curl. Sodium hydroxide, commonly known as lye, is another type of hair relaxer that is more potent and often used for coarser hair textures. It effectively straightens and relaxes hair by also breaking down disulfide bonds, but with a stronger chemical process. Given its strength, sodium hydroxide requires careful application and often comes with specific guidelines to minimize potential damage to the hair and scalp. Understanding the differences between these two relaxers is crucial for cosmetologists in order to choose the appropriate product based on the client’s hair type and desired outcome. Ammonium thioglycolate is typically used in "no-lye" relaxers, making it a preferred choice for those who may be sensitive to lye products, while sodium hydroxide remains a traditional choice