Trading standards chief Graham Hebblethwaite is warning of dangerous black henna adulterated with a chemical which can burn skin and leave scars.

Mr Hebblethwaite’s team have found PPD, a phenol compound, being used to dye Henna – also known as mehndi – black.

Henna is naturally red or brown and is “perfectly safe to use” if it has not been adulterated with dye. It is often used to decorate hands and arms and dye hair during the Muslim celebration of Eid.

Mr Hebblethwaite said: “The project we are undertaking will ensure the public can continue to use henna with full confidence.”