California Cosmetology Written ExamChemical Texture ServicesMedium
A stylist is performing a cold (alkaline) permanent wave using ammonium thioglycolate on resistant, coarse hair. What pH range is typical for alkaline waving solutions?
- A9.0 to 9.6
- B11.5 to 12.5
- C3.5 to 5.0
- D6.5 to 7.5
Show answer & explanationAnswer & explanation
Correct answer: A. 9.0 to 9.6
Alkaline (cold) waves typically have a pH between 9.0 and 9.6, which causes the hair to swell and soften, allowing faster processing without heat.
Why the other options are wrong
- B. This pH is too high and would cause excessive damage.
- C. This acidic range is far too low for alkaline waves.
- D. This near-neutral range is typical of true acid waves.
Alkaline (Cold) Wave pH
Alkaline permanent waves use ammonium thioglycolate at a pH of about 9.0–9.6, causing hair to swell and process without added heat.
- Faster processing than acid waves
- No heat required, unlike exothermic/acid waves
- Can be harsher on damaged or fine hair due to higher pH
Memory trick: 'Alkaline is Nine-point-something, No heat needed'