Colorado Cosmetology Written Practice Exam 2026 - Free Cosmetology Practice Questions and Study Guide

The pH level of hair, skin, and nails typically falls within the range of 4.5 to 5.5. This slightly acidic level is important for maintaining the health and integrity of these tissues. The acidity helps to protect against harmful bacteria and fungi, supports the natural barrier function of the skin, and aids in the preservation of moisture.

Understanding the pH level is crucial when selecting hair and skin care products, as using products with a pH that diverges significantly from this range can disrupt the natural balance. Products that are overly alkaline can strip the moisture, leading to dryness and irritation, while those that are too acidic can cause irritation and sensitivity.

In contrast, the other given ranges do not accurately reflect the natural pH levels of hair, skin, and nails. The ranges that are either too low or too high can have detrimental effects on the health of these tissues. Therefore, acknowledging that the correct pH range is 4.5 to 5.5 is essential for proper skincare and haircare practices.