Hair Colourants - why we colour, how we colour and what we daub on our heads

Changing our hair colour is one of the most radical changes we can make to our appearance and probably the only fundamental one. Plastic surgery and masquerade aside, there is precious little we can do about the size of our nose or the shape of our face. Yet, our hair gives us an element of creative freedom and allows us to shape ourselves in the image of someone else – at least temporarily. The reasons why an ever increasing number of women and men turn to chemistry for help are varied. There is, first of all, the prevalent misconception that different equals better. Secondly, constantly changing or rather constantly manipulated trends demand an almost seasonal change of hair style and colour, with those who oblige more often than not falling prey to the equally fallible equation that being à la mode means remaining young. And this leads directly to the biggest bugbear of them all, which drives many of us to the bottle: ageing. It almost seems that the fear of dying has been superseded by the fear of ageing and many a woman would no doubt rather be seen dead than with grizzled tresses. What feeds this fear seems quite often not the actual perception of oneself as old or unattractive but the fear of being treated as such by others. One could therefore conclude that fear of ageing is effectively tantamount to fear of others.
Yet whatever the motivation, hardly anyone knows what exactly they are pasting on their heads. Nor are people generally aware that their beautification efforts can backfire in the long run and severely affect their health and lifespan due to the numerous harmful chemicals, which are contained in virtually all conventional hair colourants and can either by themselves or in reaction with other ingredients cause allergies, neurological malfunctions and even cancer.

Your natural hair colour is determined by your hair’s own colour pigments, the so-called melanin pigments, of which there are two types: phaeomelanins, which are red, and eumelanins, which are black. The individual shade of your hair depends on the proportion of these two pigment types. Eumelanins determine the darkness of your hair, so a low concentration of this pigment gives you blonde hair, whilst a higher concentration results in darker shades, ranging from brown to black. A lack of melanin pigments results in grey or rather white hair – the perception of hair as grey is but an optical illusion, produced by the juxtaposition of coloured and white hairs. Melanin pigments are produced and stored in cells called melanocytes and hair greying is caused by a failure of the melanocyte stem cells to maintain the production of these melanocytes. Grey hair is not necessarily a sign of age though; it can already occur in teenagers and people in their twenties, its onset largely depending on the individual’s genetic make-up.
The pigmentation of your hair can, however, also be affected by other factors such as genetic defects (for example, albinism), hormones, climate, pollutants, toxins and exposure to chemicals. And the latter is voluntarily practised by millions of male and female hair dye users around the globe, who either don’t know about the dangers or tend to ignore them and hope for the best.

Hair colourants are divided into three different types: temporary, semi-permanent and permanent. As the name suggests, temporary colourants only change the hair colour temporarily and are easily washed out. They usually come as ready-to-use applications in a single container and colour the hair by covering its surface rather than penetrating the hair shaft as semi-permanent and permanent colours do. The degree of penetration does, however, vary. Whilst semi-permanent dyes only settle on and within the scales of the outer hair layer (the so-called cuticle) without altering the hair’s integral melanin, permanent colourants enter deep into the hair shaft and modify the hair’s natural pigments. That explains why semi-permanent colours fade after about half a dozen washes, while permanent dyes give a longer lasting colour and need to grow out.
Permanent hair colourants are mostly so-called oxidation hair dyes, which consist of two separate components that require mixing prior to the application: There is the colour precursor with an alkaline agent (which often comes in a tube) and the developer or oxidising agent (which comes in a bottle). The alkaline agent, usually ammonia, opens up the cuticle to facilitate the penetration process and reacts with the oxidising agent, usually hydrogen peroxide, to realease oxygen. The released oxygen triggers the actual colour-modifying reaction and lightens the hair’s natural melanin pigments so that the new colour can substitute the old one. The colour precursor is usually a chemical called phenylenediamine, which turns into a hair dye under the influence of ammonia and hydrogen peroxide and develops the new colour.

However, the above-mentioned chemical ingredients do not only penetrate the hair, they can also permeate the skin and seep into the body and that’s where the real problems start. Frequent and long-term use of semi-permanent and permanent hair dyes presents a clear health risk and can cause anything from hair breakage and hair loss to irritation of the eyes, skin and mucous membranes and more serious diseases like Hodgkin’s and non-Hodgkin’s lymphoma and other cancers. Highly alkaline hair products are potential irritants, as are phenylenediamines, which may produce eczema, bronchial asthma, gastritis, skin rashes and cancer. A study by New York University researchers suggests that women who have used hair dyes for a period of ten years or longer face an increased risk of developing breast cancer. Especially at risk are frequent users of darker hair colourants (black, brown/brunette).
Yet even users of temporary hair colourants are not safe from harm since many wash-out colours contain chemicals like Acid Orange 87, Solvent Brown 44, Acid Blue 168 and Acid Violet 73, which have shown evidence of carcinogenicity. In addition, many hair dyes contain resorcinol – an allergen and irritant to eyes and skin, which can also interfere with the hormone balance. Another widely used suspect cosmetic ingredient is polyethylene glycol (in its various PEG compounds), which increases the skin’s permeability and allows toxins to enter the body (see “Overview: Unsafe and Suspect Cosmetic Ingredients” on http://livelearnchange.blogspot.com/ for more details).

The good news is that there are alternative options. The first and most obvious one is to discontinue using hair dyes altogether and to accept your natural shade. Take a closer look and you’ll find that the colour you were given by nature is actually well-chosen and fits into your overall “colour-scheme”, complementing your eyebrows, eyes and complexion. After all, what use is a seductive Monroesque mane when it makes your face look like a pink marshmallow with eyebrows seemingly on loan from Ernie’s pal Bert? If you are already greying, you could take a defiant stance, make grey hair look cool and turn it into the latest must-have look. However, if vanity rules and the lure of the grass on the other side is too strong, you can always explore some of the alternative products available and take a few precautionary measures when colouring your hair:

• Avoid synthetic hair colourants which contain m-, o- or p-phenylenediamines or phenylenediamine-based ingredients.
• Try natural colouring products but check the label carefully because many so-called natural alternatives still contain the same ingredients as their conventional synthetic counterparts, albeit at lower levels – or so the manufacturers claim. Since labelling laws do not demand an indication of the exact percentage of each ingredient, buying alternatives can still be a bit of a lottery, unless you choose something purely plant-based, which consists exclusively of botanical materials such as chamomile, walnut, henna or logwood and is free from any chemical ingredients (one brand to try is Logona).
• Don’t use products which have explicit warnings or disclaimers, e. g. “may cause skin irritation”, “may cause blindness”.
• Use lighter shades as they are safer than dark colours.
• Colour your hair less frequently.
• Defer using hair dyes as long as possible; according to some experts women who start colouring their hair at forty face less of a risk than one third of those who start at thirty, whereas the risk for women who start aged twenty is twice as great.
• Don’t leave hair dyes on your scalp for longer than necessary.
• Use gloves during the application, so the chemicals don’t come into contact with the skin on your hands.
• Try techniques which reduce skin contact to a minimum, for example highlighting, streaking and frosting. The old-fashioned way of using perforated plastic caps and pulling strands of hair through the holes is actually one of the best ways of avoiding skin contact.
  
  Scientific research on the link between hair dyes and cancer is not entirely conclusive; while some studies have demonstrated a clear association, others haven’t. If the research is not conducted by an independent body, the outcome might possibly also be influenced by the interests of those who carry out the tests. Yet, for the consumer even the slightest evidence of potentially serious health risks should be reason enough to treat such substances with caution or best forego them altogether. You wouldn’t take your chances with Russian roulette either, would you?
  

Sources:
- A Consumer’s Dictionary of Cosmetic Ingredients: Complete Information About the Harmful and Desirable Ingredients Found in Cosmetics and Cosmeceuticals, Ruth Winter, (Three Rivers Press, New York, 2005)
- Canadian Cancer Society: www.cancer.ca/css/internet/standard/0,3182,3172_30513490_507522061_langId-en,00.html
- Everyday Mysteries, The Library of Congress: http://www.loc.gov/rr/sictech/mysteries/grayhair.html
- CTPA: www.ctpa.org.uk/download.asp?d1=1389
- How Stuff Works: http://science.howstuffworks.com/hair-coloring.htm
- PubMed (A Service of the National Library of Medicine & the National Institutes of Health): www.pubmed.gov, http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve/db=pubmed&doptAbstract&list_uids=15618488
- The Safe Shopper’s Bible: A Consumer’s Guide to Nontoxic Household Products, Cosmetics and Food, David Steinman & Samuel S. Epstein, (Wiley Publishing Inc, 1995)

© Manuela Hübner, 2007