Dubai Health Authority has issued a warning over the harmful effects of outlawed black henna, as members of the public prepare to try their hand at the popular Eid tradition. The authority reiterated that black henna - which has been banned in the UAE for several years - is a major health hazard and urged customers only to use approved products. The variation of the natural dye used to decorate women's hands and feet contains chemicals which can cause severe allergic reactions. Health experts said its use of dye para-phenylenediamine (PPD), which adds a black tint to the henna tattoo, can cause blistering, open sores, scarring and can even have fatal consequences if someone has an allergic reaction to it. “Black henna is a dangerous product especially when used on children. Artists drawing henna at homes use a product from an unknown source and one that is hard to trace and control,” stated Dubai Health Authority in a post on its official Twitter account. Salons and beauty centres found to be using the illegal product face fines of Dh2,000 and can be shut down if they continue to flout the law. Black henna has proven popular - despite its side-effects - because it is a darker than natural henna and lasts longer. Customers often fail to distinguish natural from black henna in its powder form, said beautician Ahlam Al Awamleh, of Golden Scissors beauty salon in Fujairah. She advised women to wait for an hour after the henna has been mixed to check its colour. “We don’t use it at all because we know its harmful and certainly not natural. Chemicals added to it give it a darker colour and long lasting results, which unfortunately women seek despite its widely reported side effects,” said Ms Ahlam. The beauty expert recommended that to get the darker colour results they desire, people can easily mix black tea or coffee with the natural henna and for a darker red colour they can add hibiscus. “The majority of beauty centres do not use black henna but the problem is caused by those who freelance and provide henna services at home, who use black henna often.”