How do I do a sensitivity test?
Clean (with surgical spirit) 1 cm2 behind the ear and apply to it, using a cotton bud, a little of the colourant product from the tube or small bottle. Re-apply 2 or 3 times allowing it to dry between each application. Carefully reseal the container. Leave for 48 hours without washing. If during this period you notice itching or reddening do not apply this product.