Pennsylvania Barber Licensure Practice Exam

What is the correct pH level for most hair products?

1. Between 2.5 and 3.5

2. Between 4.5 and 5.5

3. Between 6 and 7.5

4. Between 8 and 9.5

The correct answer is: Between 4.5 and 5.5

The correct pH level for most hair products, which is between 4.5 and 5.5, is essential because this range closely reflects the natural acidity of healthy hair and scalp. Hair has a slightly acidic pH, and keeping products within this range helps maintain the hair's cuticle integrity, allowing it to lie flat and remain smooth. Products with an appropriate pH prevent damage, frizz, and breakage while supporting the overall health of the hair and scalp. Using products outside this range can disrupt the hair's natural balance. For example, products with a significantly higher pH can cause the hair cuticle to lift, making the hair more porous and susceptible to damage. Meanwhile, excessively acidic products could lead to dryness or irritation of the scalp. Thus, the optimal pH range of 4.5 to 5.5 ensures the effectiveness of hair care products while promoting hair health.