California Barber Written ExamHair Care ServicesHard
A barber is performing a chemical relaxer service on a client with extremely coarse, resistant hair. To ensure proper straightening, the barber must select a relaxer with a higher concentration of active ingredient. Which type of chemical relaxer is generally considered the strongest and most effective for such hair types?
- ASodium hydroxide (lye) relaxer
- BThio (ammonium thioglycolate) relaxer
- CGuanidine hydroxide (no-lye) relaxer
- DAmmonium sulfite relaxer
Show answer & explanationAnswer & explanation
Correct answer: A. Sodium hydroxide (lye) relaxer
Sodium hydroxide (lye) relaxers are known for being the strongest and most effective chemical relaxers, particularly for extremely coarse, resistant hair. Their high alkalinity (pH 12.5-13.5) allows for significant breakage of disulfide bonds, resulting in maximum straightening.
Why the other options are wrong
- B. Thio relaxers are gentler than lye relaxers and are typically used for wavy to curly hair, not 'extremely coarse, resistant' hair requiring maximum strength.
- C. Guanidine hydroxide (no-lye) relaxers are considered less irritating than lye relaxers but are also less potent and often require more frequent reapplication.
- D. Ammonium sulfite relaxers are very mild, suitable for fine or color-treated hair, and would not be effective on coarse, resistant hair.
Sodium Hydroxide Relaxers
Sodium hydroxide relaxers, or lye relaxers, are highly alkaline chemical hair straighteners (pH 12.5-13.5) that are the strongest and most effective for straightening extremely coarse, resistant, or tightly coiled hair.
- Highest pH (12.5-13.5).
- Maximum straightening power.
- Requires careful application and neutralization.
- Not compatible with thio relaxers/perms.
Memory trick: Lye 'locks-up' the strongest straightening power.