1. Wash a small portion of the skin in the area chosen for the test (for example, the inner part of the forearm or behind the ear), with soap and water and pat dry.
2. Mix in a plastic or glass bowl equal parts of small quantities of the Herbatint Haircolor Gel and the glycol developer. Close bottles tightly.
3. Apply a few drops of the mixture to the test area.
4. Let dry and wait 48 hours without washing the portion of the skin tested.
5. At the end of the 48 hours, if you have no allergic reaction, you may apply the Herbatint Haircolor Gel. Should you experience redness or irritation, itching or burning in the test area, rinse area thoroughly with cold water and DO NOT color your hair with the Herbatint Haircolor Gel.