Chemical Services: Permanent Waving, Relaxing, Coloring
What the exam tests
Know the chemistry. Permanent waves and relaxers both break disulfide bonds; thio-based waves and sodium hydroxide or guanidine relaxers differ in pH and strength. Neutralizers rebuild bonds (oxidize), while relaxers require no neutralizer but need thorough rinsing and a stabilizing shampoo. Coloring: temporary (coating), semipermanent (direct dye, no lift), permanent (oxidative, lifts and deposits). Understand the color wheel, level (lightness) versus tone (warmth/coolness), developer volumes, and the patch test and strand test.
Traps to watch
Lift vs deposit is the classic trap: permanent color with low-volume developer deposits more than it lifts. Hydrogen peroxide is the developer, not the dye. A relaxer is not a neutralizer, and a wave is not a relaxer. Overlapping relaxer on previously relaxed hair causes breakage. Metallic salts and henna can react badly with oxidative color. Also watch for questions about porosity and elasticity-porous hair absorbs fast and can grab color unevenly.
Worked example
A client at level 6 wants level 9. Rule of thumb: each level of lift generally requires about one volume step of developer, and underlying pigment is exposed as you lift (red-orange at mid levels, yellow at level 9). If the target is cool, you may need to tone after lifting. If the question says "one process," check whether the requested lift exceeds what a single application can safely achieve.
Rule of thumb
Always patch test 24–48 hours before oxidative color, and strand test whenever the formula or the client's history is uncertain.