Will developer burn the hair

A developer (peroxide) will not burn your hair or scalp on its own. However, once a developer is combined with hair bleach, it can burn the hair and scalp if not used properly. When mixed with powder bleach, the formula should only be used off the scalp and watched so it doesn't over-process the hair.

You are not in danger of burning your hair or scalp when mixing any strength developer with a hair color.

To avoid problems, it is always important to read the directions on the product box and follow them precisely. When in doubt, call the toll free number that is listed on the product packaging. It is my experience that the advice you receive from these professionals, is invariably very high quality. The chemicals in hair products will react differently from one individual to the next. It is always a good idea to do the test patch that manufacturers suggest.