Wisconsin Cosmetology Practice Exam

The pH range of healthy hair is indeed between 4.5 to 5.5. This slightly acidic pH helps maintain the integrity and health of the hair cuticles, which protects against damage and keeps the hair smooth and shiny. Maintaining this pH balance is important because it supports the hair's natural moisture levels and minimizes issues like frizz and dryness.

When the hair's pH falls outside of this range, it can lead to various problems. A lower pH (such as 3.0 to 4.0) can make hair overly acidic, stressing the hair structure, while a higher pH (like 6.5 to 7.5) tends to make hair more alkaline. If hair is too alkaline, it can swell and open the cuticles, leading to potential damage and an increase in frizz and tangles. Therefore, the range of 4.5 to 5.5 is optimal for preserving hair health, making it the correct choice.