Hair dyes are widely used nowadays for fashion or to cover gray hair. While these have been deemed safe for use they raise some potential safety concerns, especially the oxidative dyes. Hair dyes safety concerns are discussed here.
Main safety concerns
The primary toxicological concerns of hair dyes, are with contact dermatitis (irritation) and long-term “potential” systemic effects (affects the whole body). Of all hair products, the most sensitizing are the paradiamine oxidation dyes and the most sensitizing ingredients of these products are p-phenylenediamine (PPD) , p-toluenediamine sulfate, and o-chloro-p-phenylenediamine.
PPD is in the spotlight because it is the primary component of oxidation hair dyes. Though PPD is a known allergen, the sensitization reactions are usually mild because the PPD is in contact with the skin only for a short time before being oxidized to a dye. Inhaling the vapors has however been said to cause lung irritations.
The sensitization symptoms from oxidation dyes are usually a discrete dermatitis at the periphery of the scalp and on the edges of the ears and itching scalp. Occasionally, eruptions occur on the face, especially around the eyelids. Those symptoms appear several hours after the dyeing process which is why it is always recommended to do the skin patch test at home before dying your whole head.
Treatment of this allergic reaction consists of oxidation of residual paradiamine with peroxide in saline solution and application of corticoid creams or lotions.
While there are concerns for hair dyes as being potential carcinogens, there is no conclusive data to relate the use of hair dyes directly to cancer occurrences.
Cancer.org quotes the following:
Researchers have been studying a possible link between hair dye use and cancer for many years. Studies have looked most closely at the risks of blood cancers (leukemias and lymphomas) and bladder cancer. While some studies have suggested possible links, others have not.
Additionally there are bigger concerns for people who work with hair dyes on a regular basis (higher exposure). Another study suggested a link because bladder cancer in stylists and hair dyes. However, these findings could not be repeated.
While we need to acknowledge the potential risks for carcinogenic activity from hair dyes, the risks have been deemed minimal to adult users by the International Agency for Research on Cancer (IARC) and agencies such as the National Toxicology Program (NTP).
However, as far as pregnant women are concerned, it is different story. To date there is no conclusive data to ensure that the fetus is safe from those chemicals. For that reason, many doctors will advise pregnant women to avoid using permanent/oxidative hair dyes at least during the first trimester.