Texas Class A Barber Written ExamChemical ServicesHard

A client with extremely curly, resistant hair desires a permanent chemical straightening service. The barber selects a guanidine hydroxide relaxer. What is a key characteristic of guanidine hydroxide relaxers compared to sodium hydroxide relaxers?

  1. AThey break fewer disulfide bonds.
  2. BThey are typically mixed with a neutralizing shampoo.
  3. CThey have a higher pH level.
  4. DThey are considered 'no-lye' relaxers.
Show answer & explanation

Correct answer: D. They are considered 'no-lye' relaxers.

Guanidine hydroxide relaxers are a type of 'no-lye' relaxer, meaning they do not contain sodium hydroxide (lye) as their active ingredient. Instead, they are a two-component system that forms guanidine hydroxide when mixed, offering a less irritating alternative.

Why the other options are wrong

  • A. Both guanidine and sodium hydroxide relaxers are designed to break a significant number of disulfide bonds to permanently straighten hair.
  • B. All chemical relaxers, including guanidine hydroxide, require a neutralizing shampoo to stop the chemical action and restore pH, so this isn't a distinguishing characteristic.
  • C. Guanidine hydroxide relaxers generally have a lower pH than sodium hydroxide relaxers, making them less caustic.

Guanidine Hydroxide Relaxers

A 'no-lye' chemical relaxer that is a two-component mixture, typically containing calcium hydroxide and guanidine carbonate, which combine to form guanidine hydroxide. They are less irritating to the scalp than lye relaxers.

  • Active ingredient: Guanidine Hydroxide (formed on mixing)
  • Classified as 'no-lye' relaxers
  • Less irritating to scalp than sodium hydroxide
  • Can be more drying to hair, requires good conditioning

Memory trick: Lye is for strong, GUANIDINE is 'NO-LYE' strong.

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