North Dakota Cosmetology Practice Exam

What is the primary effect of hydrogen peroxide in hair dye?

1. To condition the hair

2. To activate the dye and assist in the lightening process

3. To add fragrance to the dye

4. To prevent allergic reactions

The correct answer is: To activate the dye and assist in the lightening process

Hydrogen peroxide plays a crucial role in the hair dyeing process primarily as an oxidizing agent. Its primary effect is to activate the dye and assist in the lightening or bleaching process. When applied to hair, hydrogen peroxide breaks down the natural pigments present in the hair shaft, allowing for the introduction of artificial colors. This oxidation process lightens the hair by removing the existing melanin, which is the natural pigment in hair, thereby enabling the chosen hair dye to deposit its color more effectively. Additionally, hydrogen peroxide allows for the development of the dye molecules, facilitating a chemical reaction that leads to the desired hair color. This is essential for permanent hair color applications, where both the dye and the developer, which often contains hydrogen peroxide, work together to achieve the desired shade. Other functions such as conditioning, adding fragrance, or preventing allergic reactions, while important in the overall formulation of hair dyes, are not the primary roles of hydrogen peroxide. The conditioning agents are separate components designed to maintain hair health, fragrance may come from other additives, and there are specific formulations that address allergic reactions but are not related to the action of hydrogen peroxide itself.