Chemical Texture Services and Relaxing
Chemical Texture Services and Relaxing
This domain tests relaxers, neutralization, sectioning, processing, and scalp protection. The exam focuses on safety and on matching chemistry to hair condition.
Core rules
- Sodium hydroxide relaxers are strong, high-pH lye relaxers. Ammonium thioglycolate relaxers are thio relaxers. Both change disulfide bonds; hydroxide forms lanthionine bonds, while thio reduces and then re-forms disulfide bonds during neutralization.
- Do not apply relaxer to scalp, open lesions, or irritated skin. Apply protective base cream and keep relaxer off previously relaxed hair.
- Strand test for processing time and strength. Consider porosity, elasticity, and previous chemical services.
- Smooth, do not vigorously scrub or comb through while processing. Rinse thoroughly, then neutralize and shampoo as directed. Neutralizer lowers pH and removes residue; it is not optional.
- Condition after neutralizing and assess for breakage before styling.
Worked example
A client with coarse, resistant new growth and prior relaxer wants a retouch. Choose a hydroxide relaxer for the new growth only, base the scalp, section carefully, and process by the strand test. Reason: applying product through the previously relaxed ends would overlap and cause breakage. Rinsing and neutralizing follow immediately after processing; skipping neutralization leaves alkaline residue that continues to weaken hair.
Traps
- Treating neutralizing shampoo as ordinary shampoo.
- Overlapping relaxer onto previously relaxed hair.
- Combing or scratching the scalp during processing.
- Relying on clock time without a strand test.