Colorado Cosmetology Written Practice Exam

What is the pH range of an acid wave?

1. 3.5-4.0

2. 4.5-5.5

3. 6.3-6.7

4. 6.9-7.2

The correct answer is: 3.5-4.0

The correct pH range for an acid wave typically falls between 3.5 and 4.0. Acid waves, which are also known as cold waves, primarily utilize thioglycolic acid as their waving agent. This lower pH is advantageous because it helps to create a more robust curl, making the hair more manageable and easier to style without the use of excessive heat. In the context of perming solutions, maintaining a pH in this acidic range is critical, as it allows for proper hair structure alteration—breaking the disulfide bonds in the hair to create curls. By keeping the pH low, the hair cuticle remains smoother, which can improve the overall appearance of the finished style and reduce frizz. The other ranges provided typically correspond to different types of waving solutions. The pH levels above 4.0 indicate alkaline solutions, which have different chemical properties and effects on hair compared to acid waves. Understanding this is important for professionals in the field, as selecting the appropriate solution based on hair type and desired style is essential for achieving the best results in hair treatments.