The majority of permanent and semi-permanent hair dyes available in stores and used in salons contain para-phenylenediamine PPD. PPD, a coal-tar derivative dye, was first used as a commercial fur dye until consumers quickly realized that they could use it on their own hair [1].
PPD-based hair dyes entered the market at the turn of the 20 th century. Oxidative hair dyes could be made in a range of colors. The products were easy to use and worked quickly. The color result was relatively permanent. These features made PPD dyes very attractive. Oscar Wilde was one of the first public figures believed to be sensitized to PPD. This can happen to anyone. As with other allergens, a person can be born allergic to PPD, or that person can develop a sensitivity after exposure.
Only about 1. The rest are sensitized through exposure. Although sensitization rates vary depending on demographics, country, and gender, conservative estimates say around the numbers are around 6.
Prior to , there was no restriction on the concentration of para-phenylenediamine allowed in beauty products. It was even in eyelash tints, which led to corneal ulcerations and conjunctivitis [4]. Although doctors, manufacturers, and some consumers were aware of the dangers of PPD hair dyes from the very beginning, they continue to be sold in the United States.
PPD sensitization rates have risen. This means that fewer people will be able to use oxidative hair dyes and other products containing PPD; hair dye companies will see a loss in their customer base. These companies will also see increased reports of injury, and increasing numbers of lawsuits.
