Until the early 1900s, hair coloring was made from a wide range of herbal and natural dyes. Flying in the face of other chemists who found the development of hair coloring trivial and unworthy of their time, French chemist Eugene Schuller created the first safe commercial hair coloring in 1909. His invention was based on a new chemical, paraphenylenediamine, and provided the foundation of his company, the French Harmless Hair Dye Company. A year later, the name was changed to one that is more familiar today -- L'Oreal. L'Oreal, one of the hair product giants, has grown steadily over the years; the company credits advanced and applied research of new product development and expansion into markets around the world with its global success.
The two main chemical ingredients involved in any coloring process that lasts longer than 12 shampoos are:
Hydrogen peroxide (also known as the developer or oxidizing agent) -- This ingredient, in varying forms and strengths, helps initiate the color-forming process and creates longer-lasting color. The larger the volume of the developer, the greater the amount of sulfur is removed from the hair. Loss of sulfur causes hair to harden and lose weight. This is why, for the majority of hair coloring, the developer is maintained at 30% volume or less.
Ammonia -- This alkaline allows for lightening by acting as a catalyst when the permanent hair color comes together with the peroxide. Like all alkalines, ammonia tends to separate the cuticle and allow the hair color to penetrate the cortex of the hair.
In addition, various types of alcohols, which can also dry the hair, are present in most hair color.