Black henna tattoos and hair colouring - what you need to know

The topic of black henna tattoos might not be top of your list when talking to clients, but any client who has had a black henna tattoo could pose a higher risk to having an allergic reaction. Black henna is illegal in the UK, the reason being because it contains a chemical called p-Phenylenediamine (PPD) which is also found in dark hair dyes. PPD is completely legal in hair dye, but only to a certain level and it is strictly regulated. Consultant toxicologist David Basketter is one of the UK’s leading voices of authority in toxicology and explains more. “In the UK we still follow EU Legislation which states that the maximum concentration of p-Phenylenediamine (PPD) in hair colour must not exceed 2 %. Our levels of are safe and approved for its intended purpose,” he says. However, there are major concerns about black henna tattoos and the exceptionally high levels of PPD they contain. Firstly, in the UK they are illegal, and outside the UK there’s confusion about what legislation they fall under. Strictly speaking they are not cosmetics, which begs the question what legislation do they fall under? Secondly, the excessively high levels of PPD in black henna is dangerous. Often, they are applied on the street or beach, and you will have no idea of the levels of PPD being used. “As with all toxicology, the higher the concentration, the greater the risk. As hairdressers are well aware, there is a strong link between over-exposing the body to PPD and allergic reactions. Most people who have these black henna tattoos will have no idea of the PPD levels they’ve encountered,” says David. Whilst some people may have a reaction immediately, or after a few days or weeks, others can be much longer, and this is where the concern truly lies as the link is less obvious. “Black henna tattoos are designed to last a few weeks or months, but your client might not have a reaction for 10 years or more. They could have a black henna tattoo done and not notice an inflammation, but years later when you are colouring their hair, they’ll still be allergic to PPD and could have a reaction, ” he says. If your client has been over exposed to PPD, the only way to know and to avoid a severe reaction is to do a patch test before having hair colour. So what are the options? Adam Haste is the Associate Director for Sentio Insurance Brokers explains the options. “One option is to follow manufacturers’ instructions, which usually requires a client to visit the salon 48 hours before each and every treatment for a patch test,” he says. It’s worth noting that from an insurance perspective, this only covers you for use the specific colours that have been tested. Colourstart professional allergy screening is another option. It is the first clinically proven test for allergy to hair colour to be licensed by the Medicines and Healthcare products Regulatory Agency (MHRA). “This is a universal patch test for use across all colour brands. It allows for complete colour freedom as it tests against PPD, not just one specific colour,” says Adam. The beauty of Colourstart is that it can be ordered online and the test is carried out at home, is left for 2 days and any reaction is recorded 2 days after removal. It comes with its own Colourstart Vendors Extension insurance, which means you are completely covered should a reaction occur. Another option, Adam explains, is to follow your colour house's protocols. “This is different to the manufacturer’s guidelines as often the colour house is simply the brand selling the colour, and not the manufacturer.” Colour house guidelines differ; some require a patch test every 6-12 months, but some have no protocol. The advice here is to check. “Alternatively, there’s The Patch Test Kit. The hairdresser loads syringes with the exact colour they will be using and posts it to clients to test on themselves.” Adam advises if this is your method, that you inform your insurer and colour supplier first.