When using hair lightener/bleach
• Apply a small amount of the hair dye onto clean skin, either the inner area of your elbow or behind your ear, cover with a sticking plaster and leave for 48 hours
• If any irritation or swelling occurs during this time, remove product immediately with cool water and do not continue
• If at the end of the period you have experienced no adverse reaction, wash off with cool water & proceed with Test 2