Ace the Vermont Barbers and Cosmetologists Exam 2025 – Snip and Style Your Way to Success!

Ammonium thioglycolate is the key chemical commonly found in permanent wave solutions. This compound serves as a reducing agent that breaks down the disulfide bonds in hair, allowing the hair to be reshaped into curls or waves. When applied to the hair, ammonium thioglycolate transforms the natural structure of the hair fibers, making them more pliable and capable of holding a new shape once they're set with the curling method.

Other chemicals listed, such as hydrogen peroxide, are often used in the context of hair lightening or as an oxidizing agent in combination with different hair processes and treatments but do not serve the primary function of creating curls in permanent waves. Formaldehyde is associated with certain types of straightening treatments rather than perming, and glycolic acid is primarily used for exfoliating skin rather than altering hair structure. Thus, ammonium thioglycolate stands out as the essential ingredient for the process of creating permanent waves in the hair.