Montana Barber Practice Exam 2025 - Free Barber License Practice Questions and Study Guide

The ideal pH range for shampoos is between 4.5 and 5.5. This slightly acidic range is important for maintaining the health of both the hair and the scalp. Hair's natural pH is around 4.5 to 5.0, which helps keep the cuticle layer flat and intact. When hair products, such as shampoos, are formulated within this pH range, they are less likely to disrupt the natural acid mantle of the scalp and hair. This can help prevent issues like dryness and irritation while also contributing to overall hair shine and manageability.

Shampoos that fall outside this range, such as those with a pH lower than 4.5 or higher than 5.5, may strip the hair of its natural oils or cause the hair cuticle to lift. A higher pH (like that found in the 6.5 to 7.5 range) can lead to frizz and damage by opening up the hair cuticles excessively, while a lower pH (like in the 3.0 to 4.0 range) can lead to a tighter, more compact cuticle that might be too harsh for regular use. Hence, sticking to the 4.