Mix a small amount of hair colour ratio 1 : 1 1/2 of cream developer and place on the inner crease of your elbow. Wait 24 hours. If any burning itching or irritation occurs do not apply the mixture. Directions: in a non-metallic bowl mix until smooth. Caution for external use only. Contains hydrogen peroxide. In case of contact with eyes wash them immediately with water. Do not apply on eyebrows or eyelashes. Wait 24 hours between applications. Do not apply if there is an abrasion on the scalp.