We advise, and it is stated on the product instructions, everyone should perform a strand test before dyeing their hair, even if they have used the product before, as that ensures they will achieve the right result. SAFETY INSTRUCTIONS. IMPORTANT: THIS PRODUCT CONTAINS PERSULFATES. IT CAN CAUSE AN ALLERGIC REACTION WHICH IS CERTAIN RARE CASES MAY BE SEVERE. IT IS ESSENTIAL TO FOLLOW THE PRECAUTIONS BELOW: ? DO NOT USE IF: - You are sensitive to persulfates or have previously experienced a reaction to a bleaching product. - You have previously experienced any reaction after colouring your hair. - You have a lot of grey hair. - You have a sensitive, irritated or damaged scalp. ? For all questions related to your personal sensitivity, consult a doctor. ? The bleaching mixture contains hydrogen peroxide, persulfates, and ammonia. Rinse hair thoroughly after applying. ? DO NOT INHALE OR INGEST. ? In case of ingestion, do not induce vomiting, see a doctor immediately. ? WEAR SUITABLE GLOVES SUPPLIED IN THE CARTON. ? Avoid contact of the product with skin and eyes. Do not use to bleach the eyelashes or eyebrows or any usage other than bleaching the hair. Failure to comply with this instruction may cause blindness. ? Rinse eyes immediately and thoroughly if product comes into contact with them. ? If you wear contact lenses, take them out before rinsing the eyes. ? Do not exceed the maximum advised development time. Rinse hair very carefully with lukewarm water. ? In case of intense stinging, swelling or a burning sensation on the scalp or respiratory problems, rinse immediately with lukewarm water and stop use. Before doing another bleaching, consult a doctor. ? Do not use on hair that is very fine and fragile, sensitised, straightened or just after a permanent wave. ? If your hair has had a perm, wait at least 2 weeks before applying the bleaching product. ? Do not use if the hair has been coloured with henna or a progressive hair colourant. ? Never keep any mixture after application. ? Keep out of reach of children. ? Do not use on children. ? Before use, read the notices provided with the lightening creme, lightening powder and the developer creme. ? The lightening powder sachet is unterable and must be cut with a pair of scissors by following the dotted line. ? Keep the applicator away from face while opening. FOLLOW THE INSTRUCTION LEAFLET