NIC Barber Written (Theory) ExamScientific ConceptsMedium
A barber is performing a chemical hair relaxing service. The product label states it contains ammonium thioglycolate. What type of chemical reaction is primarily responsible for breaking the hair's disulfide bonds?
- AReduction
- BHydrolysis
- COxidation
- DNeutralization
Show answer & explanationAnswer & explanation
Correct answer: A. Reduction
Ammonium thioglycolate relaxers work by a process of reduction, where hydrogen atoms are added to the sulfur atoms in the disulfide bonds, breaking them and allowing the hair to be reshaped.
Why the other options are wrong
- B. Hydrolysis is the chemical breakdown of a compound due to reaction with water, not the primary mechanism for breaking disulfide bonds in thioglycolate relaxers.
- C. Oxidation is the process of removing hydrogen or adding oxygen, typically seen in the neutralizing step of perms or relaxers to reform bonds.
- D. Neutralization is a separate step that re-hardens the hair by reforming the disulfide bonds, often through oxidation.
Reduction (Hair Chemistry)
A chemical reaction in hair services where hydrogen atoms are added to disulfide bonds, breaking them apart to allow for restructuring of the hair.
- Primary action of thioglycolate-based perms and relaxers.
- Softens and expands the hair cortex.
- Must be followed by oxidation to reform bonds.
Memory trick: To 'reduce' curls, you 'reduce' the bonds!