Health Risks of Chemical Hair Dyes

Skin and other allergic reactions pose the biggest risk to hair dye users. It's difficult to say how many hair dye users suffer from allergic reactions, as most do not seek medical attention. However, there are many cases where allergic reactions to hair dyes have been severe or even fatal.

Signs of a mild reaction may only be irritation of the upper eyelids or rims of the ears, but in more severe reactions, the whole head or body may be involved.

A severe form of allergic reaction is anaphylactic shock. When this occurs, the mouth and tongue swell and the airways constrict. Anaphylaxis can be rapidly fatal, and there have been isolated cases of hair dyes causing anaphylactic shock.

Skin reactions can occur on a person's first exposure to hair dye, or can suddenly occur in a person who has been using them long-term. A patch test before every dyeing is important to help detect skin allergies, but very time dye is applied to the skin, the immune system may become sensitized, increasing the risk of future allergic reaction.

Working as a hairstylist is associated with an increased risk of skin allergies. One review found that 17-80% of stylists suffered from allergic reactions on contact with hair dye (Khumalo et al, 2006).

Hair stylists are at risk of developing occupational asthma, both from the persulfates used in bleaches and PPD from hair dyes. Long term exposure sensitizes the airways, leading to asthma attacks on exposure to the chemicals.

A number of studies have confirmed that hair stylists have higher levels of asthma than the general population.

Cancers develop due to a combination of many factors damaging the DNA of a cell in the body. While there is proof that hair dye chemicals do cause cancer in laboratory animals at high doses, it is still debated whether the low doses from hair dyes are sufficient to cause cancer in humans.

Many studies have been conducted to try to determine whether long-term hair dye use causes cancer, and it is still a controversial subject. Most studies have focused on a possible increased risk of bladder cancer. Some studies have found that women who had consistently used hair dye long term had higher levels, and other studies did not. Many official bodies have determined that the evidence so far is inconclusive.

However, new studies have linked hair dye use to development of a specific type of cancer, non-Hodgkin's lymphoma (Zhang et al, 2008). This study looked at groups of women suffering from this disease, and a control group. It was found that women who started using hair dye, particularly darker colors, before 1980 had an increased risk of developing the disease.

The strongest evidence that hair dyes can cause cancer in humans comes from studies of cancer rates in hairstylists. One study found that if a hairstylist had used hair dyes at work for 5 years or more, she had a three times higher risk of developing breast cancer. Other studies have consistently found that hair colorists have an increased risk of non-Hodgkin's lymphoma, multiple myeloma and leukemia.

Buy at AllPosters.com

If hair has been dyed many times, it becomes 'over-processed', which leads to brittle, dry hair that lack shine. Since hair only grows slowly (about 1.5cm/half an inch a month) longer hair can end up receiving multiple dye treatments. If other chemicals such as hair relaxers are used, the damage can be even worse, and over-processed hair easily breaks and splits.

Unfortunately, there is really no solution to hair damage from dyeing, other than to stop dyeing. If you do not want to stop, using a deep conditioner and products specifically for dyed hair can help reduce the damage and also maintain your color. Try to dye only your roots, to reduce the number of times the length of your hair is dyed.

P-Phenylenediamine (PPD) is present in over 2/3 of chemical hair dyes, and is known to be toxic to the immune system, skin, nervous system, respiratory system, liver and kidneys. It is the most toxic chemical in hair dyes. The European Union classifies it as a toxin and irritant that is dangerous in the environment. In Canada, its use in cosmetics is restricted and it was banned in France, Germany and Sweden.

Allergic and Skin Reactions
PPD is a skin sensitizer, meaning that it can stimulate the immune system to cause a variety of allergic reactions. The skin may become red, blister, itch and burn on exposure of PPD. Allergic reactions may also cause breathing difficulties and can even be fatal.

Cancer
Laboratory experiments have shown that PPD damages the DNA of human cells. Accumulated DNA damage leads to cancer. However, it is not conclusive whether the exposure to PPD from hair dyes is enough to cause cancer in women who dye their hair, although hair stylists who color hair at work do have higher cancer levels (see below).

Asthma
Breathing in PPD fumes can cause the airways to narrow, making breathing difficult. This can be a transient reaction, or can cause long-term asthma.

Severe effects from drinking PPD
Severe lung problems and deaths have been reported after accidental ingestion of PPD. Hair dyes should always be kept out children's reach to prevent accidents.

Resorcinol
Resorcinol receives a rating of 8 (out of 10) for hazard at the Cosmetics Safety Database. It is classified by the European Union as harmful, irritant to eyes and skin and dangerous for the environment.

It has been shown to disrupt hormonal function in rats, causing hypothyroidism (thyroid hormone deficiency), but the levels necessary were far higher than those in hair dyes (Welsch, 2008). However, autism may be caused by babies experiencing hypothyroidism while still in the womb (Roman, 2007), and there have been cases of pregnant women losing their babies after taking resorcinol by mouth (Duran et al, 2004). Resorcinol is also a skin sensitiser (Basketter et al, 2007), although it is much less potent than PPD.

Ammonia
Ammonia is irritant to the skin, eyes and respiratory system, and can cause asthma and breathing difficulties. However, it is much less toxic than PPD, and only receives a rating of 3 out of 10 for toxicity at the Cosmetics Safety Database.

Persulfates
Sodium, potassium and ammonium sulfates are present in hair dyes and bleaches, and are used in concentrations of up to 60%. However, concentrations of only 17.5% have been shown to irritate skin, and persulfates are also toxic when the fumes are inhaled, causing asthma and lung damage (Pang and Fiume, 2001). However, the Cosmetic Ingredient Review Expert Panel has concluded that they are safe for occasional use, provided that the skin is rinsed well after.

Hydrogen Peroxide
Hydrogen peroxide is used in hair bleaches. It is corrosive, and has been banned from cosmetic use in Japan and restricted in Canada. Animal studies have shown it has toxic effects on the nervous system, respiratory and digestive systems at low doses (1974). Other studies on animals have also shown that hydrogen peroxide can damage DNA, possibly leading to cancer.

Lead acetate
This is present in some hair coloring products used for gradual darkening, and is another potentially toxic chemical.Lead has well-known damaging effects on the brain and nervous system.

4-ABP
This has been linked to development of cancer.

Boxed, chemical hair dyes marketed as 'natural' typically do not contain resorcinol, ammonia or peroxide. However, they still contain at least some PPD, just a lower level. Lower levels are obviously better, but using these dyes does not completely remove the risk of suffering an allergic reaction or other side effect. 'Natural' hair dye manufacturers include Naturtint and Herbatint. Always look at the ingredients of any 'natural' hair dye to check out just how 'natural' it is, and check for the presence of the chemicals listed above.

If you are unsure how safe a dye is, the

Hair dye chemicals have been shown to cause harmful effects in laboratory experiments, but what are the real risks to women from using hair dyes? Many of these experiments used high levels of the chemicals - only about 0.5% of the hair dye applied to the head penetrates the skin, and many other studies have shown that for this level of exposure, the data is inconclusive about how much women will be harmed.

Real risks
Skin reactions are a real risk. They commonly occur after exposure to hair dyes in real-life situations, and can be life-threatening. They are something that could happen to any woman using hair dyes.

Damage to your hair is another genuine risk. If you dye your hair long-term you should always take steps to minimize damage, such as using deep conditioners, as your hair is likely to become brittle and damaged without good care.

Severe allergic reactions, causing swelling, breathing problems and skin reactions, are another real risk. This can happen even at your first exposure to hair dyes, or if you have been dyeing your hair for a while already.

Unlikely effects
While there is a chance that you may get cancer if you use hair dyes long term, it's unlikely. For cancer to occur, there need to be multiple changes in a cell's DNA, and it's unlikely that hair dyes alone would cause cancer in a real-life (not experimental) situation. However, it is possible, and although the risk is low, some studies have found that there is a higher risk of non-Hogkin's lymphoma if you use hair dyes long-term, particularly if you started before 1980.

Real risks for hair stylists
If you are a hair stylist, you will have a much higher exposure to hair dyes than someone who just dyes their hair at home. Studies have shown that hair stylists have higher rates of skin allergies, asthma and breast cancer, so the risks for stylists are real.

So, on balance, it is every woman's choice whether or not to accept these risks and dye their hair - the chemicals are known to be toxic, but the majority of women will not suffer serious side effects. However, if you are a hair stylist, there is a real risk that you will suffer some kind of health problem due to hair dye exposure.

There are several ways to color hair without using chemical dyes. None of these natural alternative have been shown to cause cancer or other harmful effects.

Henna for Red Hair
Henna is the powdered leaves of the plant Lawsonia inermis, and produces a red-orange dye. Henna is permanent, so only use it if you are sure you want red hair! The color that you will obtain will depend on the exact color of your hair to start off with, so it's important to always strand test. The henna color will oxidise, becoming less orange and brassy, over the first few days after coloring. Make sure that the henna you obtain is 100% (body art quality), as some henna blends can contain metals. These may cause your hair to turn green if it already has chemical dye on it! Henna powder if mixed with water or lemon juice and applied to the hair for several hours, then rinsed out.

Henna and Indigo for Black Hair
Dyeing your hair with henna, and then with indigo can be used to dye even blonde hair black, without using chemical dyes. Indigo produces a blue dye (it was used to dye jeans), but it colors hair black. It is a green powder like henna, and has been called black henna. However, it is not henna, and there is no such thing as black henna - henna will only dye your hair red. Indigo is used in the same way as henna, and using henna first helps darken the hair.

Honey to Lighten Blonde Hair
Honey can be used to lighten blonde hair, as it produces a weak peroxide when mixed with water. However, it does not damage hair, as its other constituents moisturize and protect the hair. Mix honey with water in a 1:4 ratio and apply to hair for an hour.

Why dye your hair at all? Natural, 'hair-color' hair is beautiful, and gray hair is beautiful too. Hair that is well cared for and styled will always look good, regardless of color.

Gray streaks add individuality and like any sign of aging, can be thought of as trophies of survival, rather than a negative. Embracing gray hair is a sign of self-acceptance and self-confidence. Special 'blue' shampoos can be used to keep gray hair bright and combat any brassy or yellow tints in gray hair.