Client-supplied imported colour and a black henna reaction
A salon's new colour line arrives, but the owner has also agreed to let a regular client, Meera, bring her own box of imported permanent colour because she says it is 'the only one that covers my grey'. The carton is printed in a language the staff cannot read; there is no batch number or date, and the shade number does not match any manufacturer chart in the salon. Meera's record shows a reaction two years ago after a 'black henna' eyebrow tint - swelling and itching that lasted four days - though she has had salon colour since with no problem. She refuses a patch test because she is in a hurry and says the salon is 'just covering themselves'. The salon stocks 6%, 9% and 12% developers; the leaflet in her box shows a picture of 12% for grey coverage. Meera wants full-head colour and a blow-dry in 90 minutes.
1. May the salon use Meera's imported colour? Justify your answer.
Read the worked answer
No. The salon cannot safely use a product it cannot read or trace.
- No ingredient list means the staff cannot identify PPD, resorcinol, ammonia or other sensitisers, or check for ingredients that conflict with her history.
- No batch number or expiry date means the product may be degraded or counterfeit, and there is no way to trace it if she reacts.
- No manufacturer instructions means the mixing ratio, developer strength and development time cannot be verified.
- Liability and insurance. Salon policies and insurers normally require professional, traceable products. If a reaction occurs with an untraceable product, the salon still carries the duty of care.
- A patch test on an unknown product is unreliable, because the formulation and concentrations are unknown.
Explain the policy calmly, offer a salon shade matched to her target, and if she declines, do not colour. Record the conversation. A signed waiver does not remove the salon's professional responsibility for a service it chooses to provide.
2. How would you patch test Meera, and how does the black henna reaction change your interpretation?
Read the worked answer
Patch test protocol: 48 hours before the appointment, clean a 2 cm area on the inner elbow or behind the ear. Mix a small quantity of the salon colour with the correct developer, apply a thin film, leave it uncovered and do not wash the area for 48 hours. Record the product, shade, batch, developer and date. Inspect at 48 hours: redness, swelling, itching, blistering or a rash is positive - do not colour and refer her for advice. A negative test reduces but does not eliminate risk, because sensitisation can develop at any time.
Black henna history: black henna often contains very high concentrations of PPD. Her four-day reaction suggests she may be sensitised, which raises the risk of reacting to PPD in permanent colour. The fact that later salon colours were tolerated does not cancel that risk: formulations differ, and a reaction can appear after repeated exposure. Patch test every time, consider a lower-PPD or alternative line, and never proceed if there is any reaction or if she refuses testing.
3. Which developer would you choose for grey coverage with a salon colour, and why is 12% inappropriate here?
Read the worked answer
Choose 6% (20 volume) for a standard permanent colour used for grey coverage on the scalp, following the manufacturer's mixing ratio and timing. Grey hair usually needs good deposit rather than lift, and 20 volume gives enough development without unnecessary scalp irritation.
Why not 12% (40 volume):
- Higher developer strength means greater alkalinity and more scalp irritation, which matters for a client with a possible PPD sensitisation.
- It lifts more than is needed for grey coverage and can give poor, uneven coverage, hot roots and more damage to the hair.
- The leaflet picture is not a substitute for the manufacturer's instructions, especially for a product the salon cannot read.
Never mix brands: the colour and developer must come from the same system. Check expiry dates. With 90 minutes for full-head colour and a blow-dry, plan sectioning and timing carefully; if the service cannot be completed safely, rebook the blow-dry rather than rush the colour.