At-home PPD allergy test: “recognised by major UK trade associations as an alternative to colour manufacturers’ own guidance”

By Kirsty Doolan

- Last updated on GMT

Consumers test using an arm patch with 65 micrograms of PPD
Consumers test using an arm patch with 65 micrograms of PPD

Related tags hair colouring Hair Allergy Hair care Hair care ingredient

A medically licensed, dermatologists’ test, Colourstart, has been recognised for use by UK hairdressing trade organisations as an alternative to the colour manufacturers’ recommendation of directly applying hair colour to the skin, which is known as the Allergy Alert Test.

The Colourstart test, which was created by UK company TrichoCare Diagnostics in collaboration with UK hair industry bodies. It tests for hair colour molecule para-phenylenediamine – known as PPD – which is present in permanent hair colour formulations and can sometimes cause a contact allergy in users.

It is a licensed medicine, approved for use by the Medicines and Healthcare products Regulatory Agency (MHRA).

PPD is an active sensitiser

As hair colour is more commonly used than ever before, PPD allergy could be an increasing issue, particularly as this allergy is still not well understood by scientists and appears to become more of a problem each time the person is in contact with the chemical.

“Hair dye is an active sensitiser,” explained CEO of TrichoCare Diagnostics, Nick Plunkett. “We don't know exactly how this happens, but we do know this fact because hairdressers are five times more likely to be allergic to it than non-hairdressers. Something happens that means that if you are using hair dye frequently at certain levels for the right amount of time on the right areas of your body, you might develop an allergy.”

“It is one of the most highly investigated products out there and has a lot of scrutiny in terms of safety. It is still considered by scientists to be safe – as long as you're not allergic to it,” he continued.

Perhaps the major issue with PPD is that someone may not know they are allergic to it and it appears to build over time and with repeated frequency of use. This means that someone could colour their hair with no issues for many years before suddenly experiencing noticeable symptoms.

Colourstart’s test can be used by consumers at home before they choose to have their hair coloured in a salon. The testing system reflects the advice of dermatologists and hair colour brands worldwide: that more effort should be made to reduce consumer exposure to hair colour and that anyone with an allergy to PPD should avoid hair colour.

“A positive result to Colourstart is a signpost for clients to seek the advice of a dermatologist,” explained Plunkett.

He said that hair industry trade organisations decided there was a need to create their own system of handling the risk of allergy at the beginning of 2023 after the European cosmetics trade association Cosmetics Europe announced a new safety guidance​ for both at-home-use and professional colour.

Although the guidance was useful, the recommendations weren’t entirely practical for in-salon, professional use of colour – as many clients aren’t able to visit their salon 48 hours before every hair colour treatment to take the screening test.

The SCCS analysed the recommendations and also highlighted that this way of testing was not standardised and therefore there was still a risk of active sensitisation by repeated use of the Allergy Alert Test (AAT).

An alternative to colour manufacturers guidance

The Colourstart test offers consumers less exposure to PPD (which is an active sensitiser) as it only tests once, rather than a salon needing to perform the AAT test each time the client has a colour appointment.

Consumers take the test themselves at home by placing a patch on their arm for the required time. They only need to retest if their health circumstances have changed, which is assessed via a risk-based questionnaire system instead. According to Plunkett this helps to “reduce overall consumer exposure to hair colour.”

As the testing process is placed in the hands of the consumer, Plunkett also highlighted how it reduces the burden of responsibility on the hairdresser to carry out the testing process. And from a consumer perspective it also “takes away the need for countless unnecessary and often inconvenient salon visits.”

He explained that “Colourstart is recognised by major UK trade associations as an alternative to colour manufacturers’ own guidance,” but said that this system also offers hair colour manufacturers: “a highly effective alternative to their own method of testing.”
The test itself costs the consumer £15. It uses 65 micrograms of PPD and is manufactured to pharmaceutical standards.

Meanwhile, the AAT standard test usually involves dabbing a small amount of colour behind the ear of the client and there is no assurance of how long the colour will remain on the skin or how many micrograms of PPD are used when performing this test.  

With Colourstart’s test, consumers use the test themselves and own their own testing record, which is shown on an app on their mobile phone.

“They share their record with the salon and the salon management system is integrated with Colourstart passport, so the salon can instantly see if the person has tested negative for a PPD allergy,” explained Plunkett.  

He continued: “By taking the test, people are self-certifying that they didn't have a positive reaction to it. It involves taking a picture of the test patch on your arm and then taking a picture of the space afterwards to show that there's no positive reaction.”

Colourstart launched the test into the UK hair industry in 2021 and now works with around 3,500 salons in the UK, from big-name chains to independents.

But the process to license the test as a medicine started in back in 2007. “We got our prescription-only medicine license in 2012 and then the general sales license – which is what is necessary for it to be used in the salon – in 2019, but were slowed down by the Covid pandemic,” he explained.

Plunkett also highlighted that this was “the first ever medicine to go to be reclassified direct from a prescription-only to a general sales list, because the hair profession needed something that it could use to screen allergy to hair colour.”

From his perspective, responsible colour testing is a measure of the quality of a hairdresser or salon, and he hopes to see more salons using this standardised option.  

“Testing is a professional obligation and if they’re not testing, the colour service is very unlikely to be insured and should be avoided,” he concluded.

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