Metallic dyes also called progressive because applications must be repeated until the desired shade is achieved, are manufactured from metallic salts containing either silver, lead, or copper. They form a metallic coating on the hair shaft and render the hair unsatisfactory for permanent waving, tinting or bleaching until you removed the metallic dye from the hair shaft, if you do you could get breakage!!!.
Metallic dyes tend to fade into peculiar colors – lead turns purple, silver turns green, and cooper turns red.
TEST-
A test for metallic salt is: Cut a strand of hair, place it in a solution of 1oz. hydrogen peroxide to 20 drops of 28% ammonia for 30 mins. remove & check back after 24 hours and look for the following reaction:
LEAD: the strand will lighten as soon as it is placed into the solution, the strand will not break after 24 hrs.
SILVER: no change in color because the solution can’t penetrate the coating, no breakage after 24hrs.
COPPER: the strand and solution will become very HOT within a few mins.and will stink to high heaven and the strand will break after 24hrs.
An example of these would be GRECIAN FORMULA made from lead Acetate, another example is Henna as some -(but not all, most are vegetable)- are made with these dyes.
