California Barber Written ExamHair Care ServicesMedium

A barber is preparing to perform a chemical relaxing service on a client with tightly coiled, resistant hair. Which of the following active ingredients is most commonly used and effective for this hair type?

  1. AAmmonium thioglycolate
  2. BSodium hydroxide
  3. CGlyceryl monothioglycolate
  4. DHydrogen peroxide
Show answer & explanation

Correct answer: B. Sodium hydroxide

Sodium hydroxide relaxers, also known as lye relaxers, are highly effective for clients with tightly coiled, resistant hair due to their strong alkaline pH and ability to break a significant number of disulfide bonds.

Why the other options are wrong

  • A. Ammonium thioglycolate is a milder relaxer, often used for permanent waving or less resistant hair.
  • C. Glyceryl monothioglycolate is a 'no-lye' perm/relaxer ingredient, milder than sodium hydroxide.
  • D. Hydrogen peroxide is an oxidizer, primarily used in coloring or to neutralize thioglycolate relaxers.

Sodium Hydroxide Relaxers

A strong alkaline chemical relaxer used to permanently straighten tightly coiled or resistant hair by breaking disulfide bonds.

  • Also known as lye relaxers.
  • High pH (10-14).
  • Not compatible with thioglycolate products.

Memory trick: Strong hair needs strong lye to lie down straight.

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