Skin sensitivity tests: how should they be done?
1- Choose an small area (1 cm2) behind the ear
2- Clean the area you will be using for the test with surgical spirit
3- Using a cotton bud, apply a small amount of hair colouring product on the cleaned area
4- Allow the product to dry
5- Reapply 2 or 3 times
6- Carefully re-seal the hair colouring container
7- Leave the hair colouring product on the skin for 48 hours, without washing
If you notice a itching or reddening on the test area, do not use the hair colouring product and consult a dermatologist.