NIC Barber Written (Theory) ExamScientific ConceptsMedium
A barber is performing a chemical relaxing service. To break the disulfide bonds in the hair, which chemical process is primarily responsible?
- AReduction
- BOxidation
- CHydrolysis
- DNeutralization
Show answer & explanationAnswer & explanation
Correct answer: A. Reduction
In chemical relaxing, the reduction process uses a reducing agent (like ammonium thioglycolate or sodium hydroxide) to break the strong disulfide bonds in the hair's cortex, allowing the hair to be reshaped.
Why the other options are wrong
- B. Oxidation is typically used to reform bonds (as in permanent waving neutralizers) or in hair coloring, not to break them for relaxing.
- C. Hydrolysis is a chemical reaction involving water that breaks a compound; while water is involved, reduction is the primary process for disulfide bond breakage in relaxing.
- D. Neutralization is the process of stopping the chemical action and reforming the bonds in their new shape, not breaking them.
Reduction (Hair Chemistry)
The chemical process in hair services, such as permanent waving and chemical relaxing, where disulfide bonds in the hair are broken.
- Breaks disulfide bonds.
- Involves the addition of hydrogen atoms.
- Allows hair to be reshaped.
- Reducing agents are used (e.g., thioglycolates, hydroxides).
Memory trick: Reducing bonds is like cutting a chain to reform it later.