Florida Cosmetology Licensing ExamHair ServicesMedium

A client with thick, coarse, and resistant hair wants to achieve a significant curl reduction and straighten their hair. Which type of chemical relaxer would be most effective and appropriate for this hair type?

  1. AAmmonium bisulfite relaxers
  2. BThioglycolate relaxers
  3. CHydroxide relaxers
  4. DSulfite relaxers
Show answer & explanation

Correct answer: C. Hydroxide relaxers

Hydroxide relaxers, particularly lye-based (sodium hydroxide) or no-lye (calcium hydroxide) formulas, are highly effective for straightening thick, coarse, and resistant hair due to their strong alkaline nature.

Why the other options are wrong

  • A. Ammonium bisulfite relaxers are mild, low-pH relaxers typically used for sensitive scalps or to create soft waves, not strong straightening.
  • B. Thioglycolate relaxers are generally milder and used for less resistant hair or softer curl patterns, not significant straightening of coarse hair.
  • D. Sulfite relaxers are very mild and primarily used for body waves or soft curls, not significant curl reduction in resistant hair.

Hydroxide Relaxers

A strong alkaline chemical relaxer, typically containing lye (sodium hydroxide) or no-lye (calcium hydroxide), used to permanently straighten very curly, coarse, or resistant hair.

  • Highly alkaline (pH 10.0-14.0)
  • Breaks disulfide bonds permanently
  • Not compatible with thio relaxers
  • Requires careful application due to strength

Memory trick: Hydroxide for hard hair, Thio for softer transformations.

More Hair Services questions