Milady Cosmetology Practice Exam

What characteristic of hair would affect how well a chemical treatment can penetrate the strands?

1. Density

2. Elasticity

3. Porosity

4. Texture

The correct answer is: Porosity

Porosity is a critical characteristic of hair that directly impacts how effectively a chemical treatment can penetrate the strands. Hair porosity refers to the hair's ability to absorb and retain moisture and other products, including chemical solutions. When hair is classified as high porosity, it has raised cuticle layers that allow for easier penetration of chemicals. This means that products can quickly enter the hair shaft, making such hair types more receptive to chemical treatments. Conversely, low porosity hair has tightly closed cuticle layers that resist moisture and product absorption, which can make it more challenging for chemical treatments to penetrate effectively. On the other hand, while density refers to the number of hair strands on a given area of the scalp, elasticity measures how well hair can stretch and return to its original length. Texture refers to the width and feel of the hair strands. Although these characteristics influence overall hair health and behavior, they do not directly determine the ability of chemicals to penetrate the hair like porosity does. In summary, understanding the porosity of hair is essential for successful chemical treatments, as it directly affects how well these solutions can be absorbed and ultimately the effectiveness of the treatment.