Arizona Cosmetology Practice Exam

What ingredient in hair coloring products is known for its lightening properties?

1. Ammonia

2. Hydrogen peroxide

3. Alcohol

4. Glycerin

The correct answer is: Hydrogen peroxide

Hydrogen peroxide is recognized for its lightening properties in hair coloring products. It acts as an oxidizing agent, which is essential in the bleaching process. When applied to the hair, hydrogen peroxide penetrates the hair shaft and breaks down the natural melanin pigments responsible for hair color, effectively lightening it. This reaction is what allows for a range of lighter shades to be achieved in hair coloring applications. The role of ammonia in hair coloring is primarily to open up the hair cuticle, allowing the color to penetrate and thus facilitating the overall coloring process, but it does not have lightening properties on its own. Alcohol is typically used in hair products for its solvent properties or as a preservative, rather than for any lightening capability. Glycerin is often included for its moisturizing properties and does not contribute to the lightening effect in hair color. Therefore, hydrogen peroxide stands out as the key ingredient that directly enables the lightening of hair.