Why A Hair Colour Skin Test Is Needed Before Your Appointment

23 May 2022 | Tincture and Colour

Has your hairdresser just told you that you need a hair colour skin test before your appointment? If this sounds like a pain to you, then keep on reading.

Hair colour skin tests are super important for your health and safety, and here’s why.


What is a hair colour skin test?

A hair colour skin test is a procedure used by our hairdressers before we apply any colour treatments to your hair.

If you know a thing or two about how hair dye works, you’ll know that it does not magically stick to your hair. The hair colouring process is fundamentally a chemical reaction; hair dye itself contains some pretty harsh chemicals, which are needed to make your colour long lasting and flawless.

As hairdressers who put your health and safety first, we always carry out a hair colour skin test before any colour appointments. In fact, patch testing hair colour is a legal requirement under Section 3 of the Health and Safety at Work Act.

So, if you’re feeling a bit bummed about having to pop in for a hair colour skin test, just know we only have your best interest at heart!


Why is a hair colour skin test carried out in hairdressing?

So, why is a hair colour skin test carried out? As mentioned, hair colour contains a variety of chemicals which are used to create your beautiful new hair colours.

Unfortunately, some people are prone to an uncomfortable skin reaction called contact dermatitis. This comes in the form of a red, itchy rash, and can either be caused by direct contact with a chemical substance, or an allergic reaction.

Hair dye isn’t the only cause of this reaction. Sometimes it can be caused by perfumes, jewellery or cosmetics.

Lady having hair coloured after doing a hair colour skin test

PPD in hair colour

A chemical called paraphenylenediamine (PPD) is commonly used in hair dye. It is the primary colouring agent in your dye, which ensures that your colour is permanent. Essentially, it means you can wash your hair without losing your colour.

Often, when reactions occur as a result of hair colour, PPD is the reason. But don’t worry, PPD is an entirely safe ingredient in hair dye and products containing it are strictly regulated.

With that being said, we still need to carry out a skin test, even if your colour does not contain PPD. It’s all simply a precaution to keep you safe and prevent any nasty reactions. 


Why do hair dye skin tests take 48 hours?

We ask that you do a hair colour skin test at least 48 hours before your hair colour appointment.

But why 48 hours? Most skin reactions will occur within 48 hours of your patch test, as we need to give your immune system enough time to respond.

Within or after 48 hours, if you have redness, swelling, irritation or burning sensations in the patch test area, this means that your skin has reacted to the product and we will not be able to go ahead with your colour.

Although a bit of redness might not seem too serious to you, if we were to go ahead with your colour after your skin has reacted, you might experience these more serious hair dye allergy symptoms (according to the NHS):


  • Itchy or raised, red skin rash
  • Swollen eyes, lips, hands or feet
  • Feeling faint or lightheaded
  • Swelling of the mouth, throat or tongue
  • Wheezing
  • Nausea or vomiting


What to expect for your hair colour skin test at the salon

There is no need to worry about getting a hair colour skin test at the salon. It’s a very quick process that you will probably forget about in a matter of minutes.

If it’s your first time booking a colour appointment with us, we will ask you to come in at least 2 days before your appointment. There’s no need to let us know since it will only take a minute, just pop in at a time that suits you.

Our team will be on hand to make sure you are comfortable. Your hair stylist will simply mix up a very small sample of the colour that will be used on your hair, and dab a spot behind your ear. And then you’re free to carry on with your day!

You should keep an eye on the patch to ensure you are not getting any irritation. Be sure to avoid washing the area in the shower for 48 hours, too.

Once the time is up, you can clean the area. You might notice a small amount of residue on the skin, but that’s about it.

Person having a hair colour skin test at the salon


Do you need a skin test if your hair has been coloured before?

If you have had your hair coloured at Tierney Salons before, there is no need to have a patch test before every appointment, so long as we are using the same products. However, if you want to switch things up, requiring us to use different products, then we will ask that you do another skin test.

In terms of having your hair coloured at other salons, we will always ask that you do a hair colour skin test before your appointment with us.

Different products contain different chemicals, so in order to keep you healthy and safe, we have a responsibility to ensure that you do not react to our dyes.


Book your next hair colour at Tierney Salons UK

At Tierney Salons, not only do we look after you, but we love looking after your hair too!

Our team of highly skilled stylists are best at delivering high quality results to give you the dream colour you’ve always wanted. We’ve recently had a fabulous new addition to our team…our super talented stylist, Beth. From blondes to vibrant hues, she’ll nail your colour service. 

Book your appointment here.