Checklist

Before your colour appointment: a hair safety checklist

Book the allergy test first

Anaphylaxis UK says an Allergy Alert Test should be done 48 hours before you colour your hair, every time, because an allergy can develop over time and ingredients can change. The test needs the full 48 hours, and it applies whether you colour at home or in a salon. Its hair dye factsheet says your hairdresser will explain the procedure and offer the test before your appointment.

Know the ingredient most likely to cause a reaction

The NHS says many permanent and some semi-permanent hair dyes contain PPD (paraphenylenediamine), a chemical known to irritate skin or cause allergic reactions. Anaphylaxis UK adds that a hair colourant containing PPD, or a related dye, must also be labelled "Contains phenylenediamines".

Mention any past reaction or black henna tattoo

The NHS page on hair dye reactions says you may be more at risk of an allergic reaction if you have had a black henna tattoo, because the paste can contain high levels of PPD. Anaphylaxis UK says that if you have had a reaction to hair dye, however mild, you shouldn't colour your hair again, including eyelashes and eyebrows, without seeing your GP and getting a referral to a specialist.

Don't rely on "PPD free" on its own

Anaphylaxis UK says choosing another shade or brand is not enough, because many use the same ingredients. In 2024 the Office for Product Safety and Standards published a safety report on a lash and brow tint sold as "PPD free" that contained toluene-2,5-diamine, a related dye that may cause a reaction in people allergic to PPD.

Check the label on anything you buy

OPSS guidance on buying and using cosmetics says the packaging must list the ingredients and name a "Responsible Person" with a UK or EU address. It suggests being wary if that information is missing, if it isn't in English, or if the product is marked "professional use only".

Know the warning signs

The NHS says common reactions include stinging, burning, an itchy rash, soreness and blisters, and that symptoms can take up to 72 hours to appear. Call 999 if lips, mouth, throat or tongue suddenly swell, or if breathing becomes difficult. These can be signs of a serious allergic reaction.

Know your rights if a service goes wrong

Citizens Advice's guidance for England says the Consumer Rights Act 2015 requires services, including a haircut, to be provided with reasonable care and skill. If they aren't, you can usually ask for the service to be done again or for a price reduction. Its guide to complaining about poor service explains how.

A note on this guide

This is general information, not medical, legal or professional advice. Rules change, so please check the official sources we link to before you make a decision.