Nevada State Board of Cosmetology Practice Exam

What is the principal ingredient in most hair color formulas?

1. Hydrogen peroxide

2. Ammonia

3. Alcohol

4. Aloe vera

The correct answer is: Ammonia

The principal ingredient in most hair color formulas is ammonia. Ammonia acts as an alkaline agent that opens the hair cuticle, allowing the hair dye to penetrate the hair shaft effectively. This process is essential for both permanent and semi-permanent hair colors, as it ensures that the pigment can adhere properly and provide long-lasting color. Ammonia's ability to raise the pH level of the hair is crucial because the cuticle, which is the protective outer layer of the hair, remains tightly closed under acidic conditions. By increasing the pH, ammonia facilitates better absorption of color molecules, leading to more vibrant and enduring results. The other ingredients mentioned, although important in their own contexts, do not serve as the primary agents for color application. Hydrogen peroxide, for example, is commonly used as a developer in the hair coloring process, where it helps to oxidize the color and activate it but is not the primary component responsible for color itself. Alcohol is primarily a solvent or preservative in formulations and does not play a central role in the coloring process. Aloe vera is known for its soothing and moisturizing properties but does not contribute to the dyeing action of hair color formulas.