Chemical Services (Coloring, Texture, Relaxing)
This domain tests the chemistry and safety sequence for color, perms, and relaxers. Expect questions on color levels, developer volumes, patch and strand tests, processing, neutralization, and contraindications.
Color rules
- The level system runs from 1 (black) to 10 (lightest blonde). Color does not lift existing color; lightener is required to remove pigment.
- Developer volume controls lift with permanent tint: 10 volume deposits, 20 volume lifts about one level, 30 volume about two, and 40 volume about three.
- A patch test checks allergy; a strand test checks timing and outcome. Virgin tint is generally applied off the scalp first, then to the new growth area last.
Texture and relaxing
- Ammonium thioglycolate perms break disulfide bonds; the neutralizer rebuilds them and stops processing.
- Hydroxide relaxers are highly alkaline and require scalp protection, careful smoothing, thorough rinsing, and neutralizing shampoo.
- Never overlap relaxer onto previously relaxed hair; apply to new growth only.
Worked example
A client at level 4 wants level 7. That is three levels of lift, so 40-volume developer with permanent tint is the starting point. You confirm a patch test, strand-test for timing and porosity, apply off the scalp first, and process visually. Reasoning: three levels is at the upper limit, so you avoid overlapping and check elasticity before proceeding.
Traps that cost marks
- Expecting tint to lift tint.
- Confusing developer volume with processing time.
- Overlapping relaxer and causing chemical burns or breakage.
- Skipping neutralizer after a perm.
- Applying chemicals over irritated scalp or broken skin.