How do I perform a skin sensitivity test?

Skin Sensitivity:

Any cosmetic product can cause an unexpected allergic reaction. For this reason, a skin sensitivity test must be carried out before each, and every use 48 hours before coloring your hair, even if you are a regular user of hair dyes. If your scalp is irritated or you have damaged or broken skin, do not complete the skin sensitivity test and do not color your hair until your scalp is fully healed. Be aware that even if a sensitivity test has been carried out, you may still experience an allergic reaction when you color your hair. The sensitivity test is an important precaution, but it is not guaranteed to avoid future allergic reactions.

How to perform a skin test:  

1. Remove any earrings. Cleanse a small area (1-2 cm) of skin behind your ear or on your inner elbow and dry gently.
2. Put on the gloves provided and carefully unscrew the caps from the Colorant (A) and the Color Developer (B) bottles.
3. In a plastic or glass bowl, using plastic utensils, mix a small amount (in equal measures) of the Colorant (A) and the Color Developer (B) until totally blended. Do not use a metal or ceramic bowl or metal or ceramic utensils. Reseal both bottles immediately to preserve the contents for a full application 48 hours later.
4. Using a cotton swab, apply the mixture to the cleansed area behind your ear or your inner elbow and allow it to dry.
5. Repeat the application two more times, allowing the area to dry between applications.
6. Leave the test mixture on the skin for 48 hours without washing, covering, or touching the test area.
7. If you experience any signs of a reaction, such as swelling, redness, blistering, rash, or itching, in or around the test area, you are sensitive to one or more of the ingredients within the formula - RINSE IMMEDIATELY AND DO NOT USE THIS PRODUCT ON YOUR HAIR.  We recommend you follow up with a medical professional to determine what you may be allergic to.

Also, see:

How do I perform a color strand test?

Hair Color Warnings & Specific Cautions!