California Barber Written ExamHair Care ServicesHard
A barber is applying an ammonium thioglycolate (thio) permanent wave solution to a client's hair. What is the primary chemical action of the ammonium thioglycolate in the waving process?
- AIt deposits artificial pigment into the hair.
- BIt breaks the disulfide bonds.
- CIt hardens the hair's protein structure.
- DIt neutralizes the disulfide bonds.
Show answer & explanationAnswer & explanation
Correct answer: B. It breaks the disulfide bonds.
Ammonium thioglycolate is the reducing agent in alkaline (cold) perms. Its primary chemical action is to break the disulfide (sulfur) bonds within the hair's keratin structure, allowing the hair to be reshaped around perm rods.
Why the other options are wrong
- A. Depositing artificial pigment is the function of hair color, not perm solution.
- C. Hardening the protein structure is not the action of a perm solution; it would prevent reshaping.
- D. Neutralizers (oxidizing agents) reform or re-harden the disulfide bonds, they don't break them.
Ammonium Thioglycolate
The active ingredient (reducing agent) in alkaline (cold) permanent waving solutions, responsible for chemically breaking the disulfide bonds within the hair structure.
- Alkaline pH (9.0-9.6).
- Penetrates hair quickly, works without heat.
- Breaks disulfide bonds, allowing hair to be reshaped.
Memory trick: Thio's Target: Breaking the Bond Barrier