Most alkaline permanent waves have a pH between?

• A. 9.0 and 9.6
• B. 5.5 and 6.5
• C. 7.0 and 7.5
• D. 11.0 and 12.0

Answer: (A)

Alkaline permanent waves rely on a strong alkaline environment to open the hair cuticle and allow the reducing agent to penetrate and break disulfide bonds. The typical pH range for these formulas is about 9.0 to 9.6. This level of alkalinity swells the hair enough for effective processing, while still being controllable with proper timing to balance safety and results. If the pH were closer to neutral or acidic, the cuticle wouldn’t swell sufficiently and the reshaping would be inefficient. If it were much higher, the process could be harsher on the hair, increasing risk of damage, which is why formulations aim for the 9.0–9.6 range. After shaping, a neutralizer then re-oxidizes and reforms the bonds in a more acidic environment, helping to reclose the cuticle and set the new wave.