PPD in hair dye and elsewhere

Michelle Berriedale-Johnson searches the web for useful information on PPD allergy in hair dye. 

Reports of fatal or near-fatal reactions to hair dye, nearly always to the PPD (para-phenylenediamine) in hair dye, appear regularly in the popular press yet there appears to be relatively little information easily available for those concerned.

This, of itself, is worrying as, for those who want a permanent hair dye, especially in a relatively dark colour, effective alternatives really do not exist.

And worse, PPD is closely related to a number of other chemicals which are extremely widely used in almost every area of modern life so, sensitisation to PPD, even if it does not have any immediate near fatal consequences, can develop into a sensitivity to the chemicals used in everything from ballpoint pens and and diesel fuel to sunscreens, drugs and foods.


So, what is PPD?
Para-Phenylenediamine, or PPD, is an ‘aromatic amine’ which is widely used in the cosmetic and other industries because of its stability, its ability to withstand high temperatures and its low toxicity levels. So apart from hair dyes and cosmetics (it is increasingly used in ‘black henna’ tattoos — see below) it is also used in printing, photocopying and photographic printing, oil, gas, grease and rubber products. It is particularly popular for hair dyes as it creates very natural colours which do not fade with washing.

PPD is a clear liquid which needs to be oxidized to develop its colour. It is during the oxidisation stage (achieved by mixing the PPD with the oxidising substance, usually hydrogen peroxide — the hair dye usually comes in two bottles to be mixed before application) that the substance can cause allergic reactions.

Once it is fully oxidised, PPD does not usually cause allergic reactions so that those who are sensitive can wear PPD-coloured wigs or fake furs without problems.

PPD is not banned anywhere in the world although the EU does have a 2% maximum level for use in hair dyes.


How many people are sensitive to PPD?
The industry claims that the percentage of users who suffer allergic reactions to PPD is tiny but there seem to be few reliable figures. And even if it is tiny, given that hair dye is used, in the UK alone, over 100 million times a year, that could still be a significant number of sufferers.


What are the symptoms?
The most usual symptoms are local irritation in the areas which come into contact with the dye — around the scalp, the ears, forehead, neck and eyelids — which will calm down relatively quickly as the dye fully oxidises.

In some cases this irritation can be quite severe and can morph into allergic contact dermatitis (eczema), hives, urticaria (reddening and swelling of the effected areas) and general unwellness. On rare occasions (most of which have made it into the popular press) the reaction has become systemic and has turned into a full, and sometimes fatal, anaphylactic attack.

If you feel that your symptoms could be more than just local and irritating, the advice is to take antihistamines and get yourself to A&E (Accident and Emergency) as quickly as possible.

In acute cases of PPD dermatitis DermNet NZ advise that you ‘wash the hair and scalp thoroughly with a mild soap or soapless shampoo to remove the excess dye. Apply a 2% hydrogen peroxide solution or compresses of potassium permanganate in a 1:5000 dilution to completely oxidise the PPD. To soothe, soften the crust and alleviate the tight feeling of the scalp, a wet dressing of cold olive oil and lime may be used. Further treatment with a topical application of an emulsion of water and water-miscible corticosteroid cream, or oral corticosteroids may be indicated.’


To guard against reactions, all hair dye manufacturers recommend that you patch test their products on your skin before using them. But while this is certainly advisable it is far from foolproof as it can take up to a week to react and patch tests can produce many false negatives. Even worse, the patch testing can itself sensitise you to the allergen, in this case the PPD.

Nor can previous safe usage be relied upon. As with other allergens, your sensitivity can ramp up quite unexpectedly so that an allergen (such as PPD) which had never before caused more than minor irritation can suddenly cause a major reaction.(An interesting article by the Guardian Weekend’s beauty columnist Sali Hughes in 2011 describes just such an event.)

However, assuming that you do not react and you go ahead and use the dye, always use gloves to apply the dye, do your best not to get it on your skin and do not leave it on longer than the recommended time. If you are using for highlights, always use a cap.

Also, beware of ‘natural’ and/or ‘organic’ products as anything which claims to be permanent, even if it is plant based, will probably include some variant of PPD. (For all the various names under which it can appear, see the bottom of the page on the DermNet NZ site.)


Black henna
While PPD is normally used for hair dye, it can also be used for temporary henna tattoos (although this use is theoretically banned in the US) to make them darker and dry quicker.

This is more dangerous than its use in hair dye both because it is used in a significantly higher concentrations and because it is applied directly to the skin while the PPD is in its oxidisation (and therefore most reactive) phase.


Sensitisation to PPD and related chemicals
Once a person has become sensitised to PPD (has suffered a significant reaction) that sensitisation is likely to remain with them for life. Moreover, they may also have become sensitised to other PPD related chemicals, of which there are, unfortunately, a large number including:

* Azo dyes — used in foods, medication, other hair dyes, ballpoint pen inks and diesel oil
* Para-aminobenzoic acid (PABA) — used in over-the-counter sunscreens
* Benzocaine, procaine, sulfonamides, sulfones, sulfa and para-aminosalicylic acid — all widely used in anaesthetics and drugs.
* Parabens

The sufferer could then develop a wide range of sensitivities which make everyday living very difficult.


Alternatives to PPD
Well, that really is the problem — there just aren’t any. Well, not any that are as effective as PPD anyhow.

A study reported in Medscape Today found that over 50% of 35 patients who were allergic to PPD could tolerate hair dyes made with one relatively effective alternative, para-toluenediamine sulfate (PTDS).

Para-aminodiphenylamine (PADA), paratoluene diamine (PTDA) and 3-nitro-p-hydroxyethylaminophenol have also been used in hair dyes but although less allergenic than PPD, they can still cause sensitivity problems and are not as effective.

Two more common alternatives, Toluene-2,5-diamine (TD) and Toluene-2,5-diamine sulphate (TDS), both of which also need to be mixed with hydrogen peroxide to achieve oxidisation, are more effective but only marginally less allergenic than PPD itself — although it is possible to be allergic to PPD and not to TD or TDS — and vice versa.

Some suggest using dilute bleach as an alternative if you want to go blonde.


The bottom line…
However, the general consensus would seem to be that if you really want to be safe, just do not try to dye your hair permanently.

If may be a bore to have to tint with genuinely ‘natural’ or vegetable dyes each time you wash but it is really the only way you can be virtually sure to be safe. You may find the totally natural plant powder colouring agents by It’s Pure work well for you (use SM10 for 10% off), and there’s an interesting article on their site — Allergic to Hair Dye? — which might help further.


Other resources
See our article on PPD-free and other natural hair dyes here.

DermNet NZ have a very helpful page of PPD, which includes as useful list of the alternative names under which you might find it and a list of cross reacting chemicals.

Allergy UK offers a useful factsheet on reactions to hair dye which you can download from their site here.