In recent years, there has been an increasing amount of warnings and argument over the use of hair dyes.
Depending on the source you encounter, either all hair dye is harmful and should be avoided at all costs, or the problem has been
dealt with and hair dyes are completely safe when used as directed. As with most contested issues, the reality lies somewhere in the
middle of the extremes. There have been problems encountered and reported to the FDA concerning the use of Coal Tar dyes in many cosmetic
products, namely in hair coloring products.
In 1938, the FDA passed the Food, Drug and Cosmetics Act which would allow for the banning of
products deemed harmful to the public, but lobbying by the haircolor industry resulted in hair dyes using Coal Tar being exempted when
the act was passed. While the exemption prevents the prohibition of the hair dyes with Coal Tar-based ingredients, the FDA does require
that warning labels acknowledging the potential for allergic reactions be placed on these products, as well as instructions for patch
testing to determine potential sensitivity.
This requirement is motivated by concern over allergic sensitivity to Coal Tar ingredients in hair
dyes. It should also be noted that all cosmetic products containing ingredients whose safety for use on humans has not been substantiated
must carry the warnings and instruction for patch testing. Even so, this requirement is largely voluntary and the FDA can do little
unless the product is determined to be harmful under conditions of customary use. (This last caveat has many groups up in arms as what
they deem the ineffectiveness of the FDA in this area of promoting public safety.)
The most recent studies on Coal Tar-based hair colors state that “women using permanent hair dye at
least once a month for a period more than one year more than double their risk of bladder cancer” (USC School of Medicine, Gago-Dominguez
et al. 2001). It also stated that women who are genetically vulnerable to bladder cancer (so-called “slow acetylators” who are exposed to
some carcinogens for longer periods of time) using permanent hair dye at least once a month for a period of 10 years or more had more
than 4 times more risk for bladder cancer. The study does not state the base line “risk” for bladder cancer development, which would
be imminently useful in understanding the amount of risk being purported.
It should also be noted that salon professionals had much greater increase of risk of bladder cancer
due to hair dye exposure than the “non-professionals” referred to above.
The substance called Coal Tar is created as a by-product of the process of converting bituminous
coal into coke (a hot-burning fuel used in smelting iron). The development of the Coal Tar products industry was the result of an
accident during an attempt to make an artificial form of quinine in 1856. William Perkins’ failed experimentation resulted in producing a
purplish powder which he later discovered was useful as a textile dye. In continued experimentation more “Coal Tar Dyes” were created
in new colors. Their popularity and thus profitability came from their ability to create brighter and more lasting colors than other organic vegetable dyes.
Concern over Coal Tar-ingredients has resulted in many manufacturers removing known offenders from
their ingredients and replacing them with other compounds. The safety of these compounds has been questioned by some scientists because
hey have similar chemical structures to the ingredients they replaced.
If you are concerned about the existence of Coal Tar ingredients in your hair products, the following
is a list of some of the substances to look for in the ingredients list of your haircolor when you shop. These ingredients have been
found to penetrate the skin of humans and animals in testing, and are reported to cause cancer in at least one animal species: