California Barber Written ExamHair Care ServicesHard
A client with extremely coarse, resistant hair desires a permanent wave. To ensure sufficient curl formation, the barber might choose a perm solution with a higher concentration of which active ingredient?
- AAmmonium thioglycolate
- BGlyceryl monothioglycolate
- CHydrogen peroxide
- DSodium bromate
Show answer & explanationAnswer & explanation
Correct answer: A. Ammonium thioglycolate
Ammonium thioglycolate is the primary reducing agent in alkaline (cold) perms, which have a high pH and are strong enough to effectively break the strong disulfide bonds in coarse, resistant hair, leading to significant curl formation.
Why the other options are wrong
- B. Glyceryl monothioglycolate is the active ingredient in acid-balanced perms, which are gentler and less effective on resistant hair.
- C. Hydrogen peroxide is the active ingredient in neutralizers, which reform the disulfide bonds, not break them for curl formation.
- D. Sodium bromate is also a neutralizer (oxidizing agent), not a waving solution ingredient.
Ammonium Thioglycolate
The active ingredient and reducing agent in alkaline (cold) permanent waving solutions, known for its ability to effectively break strong disulfide bonds in resistant hair.
- Primary reducing agent in alkaline perms
- High pH (9.0-9.6)
- Strong action on coarse, resistant hair
Memory trick: Thio breaks, Peroxide sets, Acid is gentle, Alkaline is strong.