What is the pH range of an acid wave?

The pH range of an acid wave is particularly important in the context of hair perming, as it influences the hair’s structure and bonding properties. Acid waves generally have a pH range of approximately 4.5 to 7. This range is slightly acidic to neutral, which allows for softer waves and is less damaging to the hair's overall structure compared to alkaline waves.

The reason the pH needs to be in this specific range is that lower pH levels can allow for better control of the perming process and reduce the swelling of the hair cuticle, leading to a smoother and more manageable finish. The balance of the pH within this range helps in effectively breaking down the disulfide bonds in the hair without overly damaging the hair shaft.

Ranking the alternatives based on their pH values, the other ranges would either be too acidic or too alkaline for the characteristics of an acid wave. Hence, when performing perming, it's essential to stick to the right pH level to achieve optimal results while minimizing hair damage.