California Barber Written ExamHair Care ServicesMedium

A barber is preparing for a permanent waving service on a client with fine, fragile hair that has been previously colored. Which type of perm solution would be the most appropriate choice to minimize damage while still achieving a noticeable curl?

  1. AThioglycolate-free perm
  2. BExothermic perm
  3. CAlkaline (cold) perm
  4. DAcid-balanced perm
Show answer & explanation

Correct answer: D. Acid-balanced perm

Acid-balanced perms (also known as true acid or acid-balanced waves) have a lower pH (4.5-7.0) and are gentler on the hair, making them ideal for fine, fragile, or color-treated hair. They minimize damage compared to alkaline perms, which have a much higher pH.

Why the other options are wrong

  • A. Thioglycolate-free perms (often based on sulfites) are sometimes used for sensitive clients, but 'acid-balanced' directly refers to the pH that makes it gentle for damaged hair.
  • B. Exothermic perms are a type of perm that creates its own heat, but their chemical composition can be alkaline or acid, so it's not the primary factor for gentleness.
  • C. Alkaline perms have a high pH (9.0-9.6) and are too strong for fine, fragile, or color-treated hair, leading to potential damage.

Acid-Balanced Perms

Acid-balanced permanent waves have a lower pH (4.5-7.0) than alkaline perms, making them gentler and suitable for fragile, fine, or previously colored hair to minimize damage.

  • pH range of 4.5 to 7.0.
  • Requires heat to process (usually from a dryer).
  • Gentler on hair, less swelling.
  • Ideal for fragile, fine, or color-treated hair.

Memory trick: Acid for delicate, alkaline for tough.

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