Chemical Services: Permanent Waving, Relaxing, and Color
The chemistry
Chemical texture services and color both depend on pH, processing time, and the hair's condition. Permanent waving uses a reducing agent (thioglycolate or similar) to break disulfide bonds, then a neutralizer (oxidizer) to rebuild them in the new shape. Relaxers use a strong alkaline agent to break bonds and straighten; they require a base cream to protect the scalp.
Color
- Temporary color coats the cuticle.
- Semipermanent deposits color without lifting.
- Permanent uses developer to lift the cuticle and deposit color; the developer volume determines lift.
- Patch test is required 24–48 hours before color or lightener.
Key safety rules
- Do not apply chemical services over irritated scalp, open lesions, or hair with poor elasticity.
- Strand test before any chemical service.
- Follow manufacturer timing; never exceed it.
- Relaxer vs. wave: never apply a relaxer over a fresh wave or vice versa without proper waiting and analysis.
Traps
- Confusing the reducing agent (wave) with the oxidizing neutralizer.
- Skipping the patch test - a classic exam trap.
- Assuming higher developer volume always means better results - it risks damage.
- Forgetting base cream on scalp for relaxers.
Rule of thumb
Test, time, and protect. Strand test, patch test, base cream, and clock.
Worked example
A client with a scalp abrasion requests a relaxer. Correct action: postpone the service until the scalp heals; a relaxer over broken skin risks chemical burn.