Also known as paraphenylenediamine, 1,4-diaminobenzene or 1,4-phenylenediamine, PPD is an aromatic amine used as a component of polymers , hair dyes, rubber chemicals, fibers, textile dyes, and pigments.PPD is used in almost every hair dye on the market, regardless of brand; the darker the color, usually, the higher the concentrations. Even some of the so-called "natural" and "herbal" hair colors, while ammonia-free, contain PPD. Some products sold as henna have PPD added, particularly "black henna."
Unfortunately PPD is known to cause allergic reactions; and as a result its use in hair dyes is controversial.
• The Harvard School of Public Health's epidemiology department discovered that women who use hair coloring five times or more annually are twice as likely to develop ovarian cancer as women who never use hair dye.
• According to a study published by The American Journal of Epidemiology, hair stylists who worked with hair dyes for five years or more had tripled their risk of developing breast cancer.
• According to the American Cancer Society, people who used dark hair dye for two decades or more had a four times greater risk of dying from cancers of the immune system.
However, due to the inconsistency of the findings, the EPA has yet to classify PPD as a potential carcinogen and no warning labels are required on hair dye packages.
