7.4 Perming Special Cases: Color-Treated, Damaged, Partial & Previously Treated Hair
Key Takeaways
- Special considerations is a distinct lettered sub-topic under Permanent Waving, covering overprocessed or damaged hair, hair carrying metallic, compound, or mineral-based color, and the test curl.
- A positive 1:20 metallic salt test contraindicates every chemical texture service; the only remedy is to grow out or cut off the affected hair.
- Color-treated and highlighted hair is more porous and processes faster, so it calls for an acid-balanced or true acid wave, a larger rod, reduced processing time, and a preliminary test curl.
- Hydroxide-relaxed hair can never be permed and thio-relaxed hair can only be permed by an experienced practitioner after a successful test curl, because hydroxide and thio chemistry are mutually incompatible.
- Over-processed hair is already too curly at the scalp and too weak at the ends; the correct response is reconstruction and cutting, never a corrective perm.
What "Special Considerations" Means on the Blueprint
Section VII of the Pennsylvania outline ends with "H. Special considerations," broken into three items: overprocessed or damaged hair, hair with metallic-based, compound-based, or mineral-based color, and test curl. Section VIII ends with the same list, substituting the strand test. These are the items that separate a competent perm from a chemical disaster, and they are written into the blueprint precisely because the consequences are irreversible.
Metallic, Compound, and Mineral-Based Color
Why it matters
Metallic dyes — often sold as progressive or gradual color and containing lead, silver, or copper salts — deposit a metal film on the hair shaft. Compound dyes combine metallic salts with a vegetable dye such as henna. When any oxidizing or strongly alkaline professional chemical meets that metal film, the reaction is violent: rapid heat generation, smoke, boiling, foul odor, green or gunmetal discoloration, and disintegration of the hair.
The 1:20 metallic salt test
| Step | Action |
|---|---|
| 1 | Take at least 20 strands of hair from an inconspicuous area, bound at one end |
| 2 | Mix 1 ounce of 20-volume hydrogen peroxide with 20 drops of 28% ammonia in a glass bowl |
| 3 | Immerse the strand bundle for 30 minutes |
| 4 | Remove, dry, and read the result |
| Result | Interpretation |
|---|---|
| Boiling, smoking, foaming, heat, or the strand disintegrating | Lead — metallic salts present. Contraindicated. |
| Strand lightens in under 30 minutes | No metallic salts; the hair may be processed |
| Strand does not lighten at all after 30 minutes | Coated with a metallic or compound dye; contraindicated |
| Strand splits or has a foul odor | Silver — contraindicated |
The only remedy
There is none that a salon can apply. Metallic and compound color must be grown out or cut off. Do not attempt a perm, a relaxer, a lightener, or an oxidative color over it, and do not accept the client's assurance that "it was only a rinse." Document the test, the result, and the refusal on the service record.
Color-Treated, Highlighted, and Lightened Hair
Oxidative color and lightening raise porosity and remove cortical protein before the perm ever begins. Adapt on four axes:
| Variable | Adaptation |
|---|---|
| Formulation | Choose an acid-balanced wave (pH 7.8 to 8.2) or a true acid wave (pH 4.5 to 7.0) rather than an alkaline cold wave. Lower pH means less cuticle swelling and less protein loss. |
| Rod size | Go one size larger than the target curl. Porous hair takes a tighter curl than the rod diameter predicts. |
| Processing | Shorten the time and check the test curl early and often. Never rely on the label time for porous hair. |
| Pre-treatment | Apply a protein filler or porosity equalizer to even out absorption between resistant roots and porous ends. |
Highlighted hair is the hardest case, because the same head carries lightened strands and untouched natural strands with completely different porosities. Test-curl on both. If more than roughly half the hair has been lightened to a pale stage, decline the perm and offer a low-heat setting service instead.
Previously Relaxed and Chemically Straightened Hair
This is the highest-stakes item in the sub-topic.
| Prior service | May the hair be permed? |
|---|---|
| Hydroxide relaxer (sodium, calcium, lithium, potassium, guanidine) | Never. Hydroxide relaxers convert disulfide bonds to lanthionine bonds by permanently removing one sulfur atom. Lanthionine bonds cannot be reduced and re-formed, so there is nothing for a perm to work on — and applying thio chemistry over hydroxide-treated hair melts it. |
| Thio relaxer | Only with great caution: the bonds were reduced and re-oxidized, so they can in principle be reduced again, but the hair is already weakened. Requires a preliminary test curl, a mild formulation, and an experienced practitioner. |
| Keratin smoothing treatment | The disulfide bonds were never broken, but the cuticle carries a heat-sealed polymer film that blocks penetration and produces uneven results. Wait for the treatment to wear off. |
| Japanese thermal straightening | No. The hair has been chemically reduced and thermally reset; a perm over it causes severe breakage. |
When the history is unknown, test. Take a small strand, apply waving lotion, and observe. Hair that softens to mush, dissolves, or slides apart between the fingers has been hydroxide-treated. Stop.
Over-Processed and Damaged Hair
Recognizing over-processing
Over-processed hair presents a characteristic and counter-intuitive picture: it is too curly near the scalp and limp, frizzy, or straight at the ends, because the ends were destroyed while the base continued to process. Additional signs are a gummy feel when wet, no stretch-and-return, and strands that separate under light tension.
The wrong answer and the right answer
The tempting fix — a corrective perm to "even it out" — is always wrong. Reduction chemistry on hair that has already lost its disulfide framework destroys it.
The correct protocol:
- Cut off the destroyed hair. This is not optional; the affected length will not recover.
- Reconstruct with hydrolyzed protein treatments to restore temporary tensile strength, alternated with moisture to prevent protein overload.
- Impose a chemical moratorium — no perms, relaxers, lighteners, or high-lift color until healthy new growth is established.
- Convert the client to non-chemical texture — rollers, flexi-rods, and low-heat thermal styling from Chapter 6.
- Prescribe home care — sulfate-free cleansing, leave-in conditioner, heat protectant, and reduced heat-tool temperature.
Partial and Specialty Perms
A partial perm treats only part of the head — most often the crown for lift, the nape for movement, or the interior for support under a longer perimeter.
Two rules govern every partial perm:
- Blend the transition. Use progressively larger rods at the boundary between permed and unpermed hair so there is no visible line where the texture changes.
- Protect the unpermed hair. Waving lotion running out of the permed panel onto untreated hair produces a hard, unplanned wave. Isolate the untreated sections with cotton and plastic, and rinse the boundary thoroughly.
Other specialty applications from Section 7.3 apply here directly: piggyback (double-rod) wraps for hair too long for a single rod, spiral wraps for an elongated corkscrew curl, and bricklay patterns to prevent visible split partings on fine or thinning hair.
Reading the Preliminary Test Curl
The test curl is the blueprint's own final item, and it appears in two forms.
A preliminary test curl is performed before the full service on questionable hair: wrap two or three rods in different areas, apply lotion, process, and evaluate. It answers three questions — will this hair take the curl, how long will it take, and can the hair survive it.
A processing test curl is performed during the service:
- Unfasten a rod in the area you expect to process slowest, and again in the fastest area.
- Unwind the rod 1.5 turns without pulling or stretching the hair.
- Look for a firm, well-defined S-pattern whose size matches the diameter of the rod.
- If the S is loose or absent, re-fasten and continue processing, checking again at short intervals.
- If the S is tighter than the rod diameter or the hair feels gummy, the hair is over-processed — rinse and neutralize immediately.
Do not comb the strand, stretch it, or unwind the rod completely; each of those distorts the reading and the strand cannot be re-wrapped accurately.
A client's hair has been treated with a sodium hydroxide relaxer. She now wants a permanent wave. What is the correct response and the underlying chemistry?
A strand bundle immersed in a mixture of 1 ounce of 20-volume hydrogen peroxide and 20 drops of 28% ammonia begins to boil and smoke within minutes. What does this indicate and what is the correct action?
A cosmetologist checks a processing test curl and finds an S-pattern noticeably tighter than the diameter of the rod, and the hair feels gummy between the fingers. What has happened and what should be done?