Black henna used for making tattoos can cause allergic skin reactions and even permanent scars and should not be used, the Health Ministry warned on Wednesday.The ministry said it had recently received numerous reports of swelling, redness, blisters and other symptoms from reactions to the henna dye.Henna is a natural plant dye with a reddish-brown color widely used for cosmetic purposes in the Middle East and the Far East. Pure henna is considered safe, with skin reactions rare. But when used for tattoos, a chemical dye called PPD is added to make it black. PPD is known to be an industrial allergen.If the chemical is added to henna to produce “black henna,” it has a significant risk of causing allergic reactions. Its use is thus prohibited for making tattoos on the skin – but despite a warning to that effect on the product packaging, the law is not widely enforced.Black henna is also widely used in Israel to make temporary tattoos at fairs and stands.According to reports in Israel and abroad, they can cause scars. If an allergic reaction results from such tattoos, the ministry counsels that immediate medical attention should be sought.