My friend D is a dark-haired beauty who dyes her raven (and currently straightened) locks to cover up the odd gray hair. She uses a permanent hair color called Naturtint ($17.99) and she asked me to check out the ingredients. Since a 2001 study by the International Journal of Cancer found that people who use permanent hair dye (either black or very dark dyes) are twice as likely to develop bladder cancer as those who go au naturel, I was more than happy to take a look to see if Naturtint (dark chestnut brown) is safe.
I'll cut straight to the car-chase. Naturtint's ingredients (despite the fact it makes a big deal about using vegetable ingredients) are positively hair-raising. Like many dark hair dyes, Naturtint uses p-Phenylenediamine. This is in widespread use and here is what the Environmental Protection Agency has to say about it: "p-Phenylenediamine is primarily used as a dye intermediate and as a dye. Acute (short-term) exposure to high levels of p-phenylenediamine may cause severe dermatitis, eye irritation and tearing, asthma, gastritis, renal failure, vertigo, tremors, convulsions, and coma in humans. Eczematoid contact dermatitis may result from chronic (long-term) exposure in humans. In rats and mice chronically exposed to p-phenylenediamine in their diet, depressed body weights, but no other clinical signs of toxicity, were observed in several studies."
p-Phenylenediamine gets a perfect score from the Environmental Working Group. Make no mistake, that is not something to brag about.
This was reason enough for me to shoot an email to my friend and urge her to look for an alternative to Naturtint (one of our reviewers liked Surya Henna). However, I'm not going to let Naturtint off the hook for the other nasties in this hair dye. PEG-2 Oleamine is often used as a thickener in food. Like all PEGs, it may contain contaminants and shouldn't be used on broken skin. Ethanolamine is also known as acetamide MEA and the European Union classifies it as corrosive and harmful if in contact with the skin. However, the industry body, Cosmetic Ingredient Review, proclaims it is safe in concentrations up to 7.5%.
There isn't much information on 4-amino-2-hydroxytolueno.p-aminophenol other than a 2004 paper in the International Journal of Toxicology saying that it there was insufficient data to support its safety. The European Union says it can cause allergic reactions. Another common component of hair colorants is 2-Methyl-Resorcinol. A 1980s study found that this was moderately toxic, but also concluded that it was safe for cosmetic use. 4-Chloro Resorcinol is usually used at concentrations of less than 1% and hair dyes that include it usually carry a sensitivity warning. It can be an eye irritant and emits toxic fumes if heated (source) and EWG rates it a moderate hazard. Oxyquinoline Sulfate is considered safe for rinse off products, but there is insufficient data to pronounce it safe for leave on products, according to the CIR.
To be fair to Naturtint, the hair dye ingredient, m-Aminophenol, has been deemed safe by the EU.
Ingredients in Naturtint: PEG-2 Oleamine, Aqua (Water), Cocamide DEA, Alcohol Denat (Alcohol), Propylene Glycol, Ethanolamine, Oleic Acid, Hydrolized Vegetable Protein (Triticum Vulgare, Soy, Corn, Avena Sativa), Sodium Sulfite, Sodium Ascorbate, Tetrasodium EDTA, Parfum (Fragrance). (+/-) p-Phenylenediamine, 4-Amino-2-Hydroxytolueno.p-Aminophenol, 2-Methyl-Resorcinol, m-Aminophenol, 4-Chloro Resorcinol, N,N-Bis (Hydroxyethyl)-p-Phenylenediamine Sulfate, 2-Amino-4-Hydroxy-Ethylaminoanisole Sulfate
Ingredients in ColorFix: Aqua (Water), Hydrogen Peroxide, Cetearyl Alcohol, Laureth-3, Ceteareth-20, Cetyl Alcohol, Oxyquinoline Sulfate
Editor's Note 2017: Naturtint has since revised the ingredient list and the latest is published on the right