Coal Tar Hair Dyes

Hair color warning
Hair Care Cautions
In recent years, there has been an increasing number of warnings and arguments over the use of hair dye. Depending on the source you encounter, either all hair dye is harmful and should be avoided at all costs, or the problem has been addressed 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 issues encountered and reported to the FDA concerning the use of Coal Tar dyes in many cosmetic products, specifically in hair coloring products.
In 1938, the FDA passed the Food, Drug, and Cosmetic Act, which allowed for the banning of products deemed harmful to the public. However, lobbying by the hair color industry resulted in hair dyes using Coal Tar being exempted when the act was passed. While the exemption prevents the prohibition of 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 sensitivities 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 warnings and instructions 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 over what they deem to be the ineffectiveness of the FDA in 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 of 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 four times more risk for bladder cancer. The study does not state the baseline "risk" for bladder cancer development, which would be immensely useful in understanding the amount of risk being purported.
It should also be noted that salon professionals had much greater 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 byproduct 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 dye for textiles. 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 long-lasting colors than other organic vegetable dyes.
Concern over Coal Tar-containing 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 they have similar chemical structures to the ingredients they replaced.
Use at own risk sign
Photo: Erik Mclean/Pexels
If you are concerned about the presence 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 hair color 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:
•   4-methoxy-m-phenylenediamine
•   2,4-diaminoanisole
•   4-chloro-m-phenylenediamine
•   2,4-toluenediamine
•   2-nitro-p-phenylenediamine
•   4-amino-2-nitrophenol
In April 1993, the FDA Consumer released recommendations for those people concerned about the reported cancer risks of Coal Tar hair dyes. They state that consumers might also want to consider using henna, which is largely plant-derived, or hair dyes that are lead acetate-based. These colorings do not fall into the coal-tar dye category and therefore any additive ingredients they contain have been tested for safety before marketing, in accordance with FDA requirements.
Henna products on the market can give a range of colors, from dark brown through various reddish-brown and lighter red to reddish-blond shades. They cannot, however, lighten hair. Lead acetate dyes gradually darken hair and are commonly used in progressive type hair colorings, such as those advertised as being for men. None of these colors may be used on eyelashes or eyebrows. They also listed the following precautions for people who choose to dye their hair with Coal Tar dyes:
•   Don't leave the dye on your head any longer than necessary.
•   Rinse your scalp thoroughly with water after use.
•   Wear gloves when applying hair dye.
•   Carefully follow the instructions in the hair dye package.
•   Never mix different hair dye products, because you can potentially cause harmful reactions (if not an unappealing hair color).
This last precaution is especially true of those tempted to mix hair color processes by using some traditional hair color over hair that has been colored with metallic dyes such as the lead-acetate dyes mentioned previously. The end result could be that you leave all of your hair in the sink due to the interaction between the ingredients in traditional hair dye (namely peroxide) and the metallic salts in the gradual hair dyes.
It should also be noted that in January 2002, the FDA established a "safe conditions of use" regulation for hair colors using lead acetate and has required the following warning to be carried on all products containing lead acetate:
Caution: Contains lead acetate. For external use only. Keep this product out of children's reach. Do not use on cut or abraded scalp. If skin irritation develops, discontinue use. Do not use to color mustaches, eyelashes, eyebrows or hair on parts of the body other than the scalp. Do not get in eyes. Follow instructions carefully and wash hands thoroughly after use.
This was a result of concerns of potential "lead poisoning" due to absorption through the skin of the lead in the product.
As a professional stylist, I am concerned about potential hazards in the products I use, both for my own safety and the safety of my clients. I would encourage those individuals who choose to use hair color products at home to exercise caution in selecting the products they use. Take the time to read the labels and look for ingredients like those listed above. If you are concerned about potential cancer risks, look for products without these ingredients, or for statements declaring the absence of coal tar dyes.
However, I urge you not to accept anything you read (even from me) at face value. One of the greatest assets we have in our modern age is the ability to access information to make truly informed decisions. Choose sources you trust that provide references for the sources of the information they provide. When you encounter information that seems adamant on one viewpoint, consider the source. In other words, don’t expect to get accurate, balanced information on the potential hazards of permanent hair color from a website that advocates or markets vegetable hair dyes. Stay informed, stay smart, and make good choices.