Many people avoid artificial colours in their foods, but don't check out the colours in cosmetics and personal care products. It is only in recent years that cosmetics have started to carry a full list of ingredients on their packaging.

Making sense of the ingredients can be difficult for the lay person. This is particularly true for colourings, which often go under the guise of numbers rather than names.

In many countries colours in cosmetics are listed as colour index numbers. C.I. numbers are allocated by the Society of Dyers and Colourists. The scheme covers colours used in food, personal care products, cosmetics, household products and fabric dyeing. So, for example you will not normally see 'tartrazine' listed in your lipstick ingredients, but it may be there listed as C.I. 19140. Erythrosine will be listed as C.I. 45430, and so on.

The USA uses a different system: the FD & C colors have been categorised by the American Food & Drink Administration for use in foods, drugs and cosmetics. So in this system tartrazine is FD & C yellow 5, and amaranth is FD & C red 2.

The 'E Number' system is used by the European Community (EC). This is a system of giving code numbers to food additives, some of which are also used in cosmetics and personal care products. This system is also used in some other countries but without the E prefix, so E102 becomes simply colour '102'.

All this confusion for the average consumer would not be important, but for the fact that some of these colours are known to cause problems in susceptible individuals. For example, tartrazine (also known as FD & C Yellow 5, CI 1914 and EI02) can cause migraines, itching, rhinitis and agitation in susceptible individuals. Many individuals avoid its use in food, but do not realise how extensively it is used in cosmetics, such as lipstick, and personal care products.

The big worries in terms of colours in cosmetics and personal care products are lipstick, coloured lip balms, lip gloss and lip pencils, because anyone who uses these regularly 'eats' a fair quantity over their life time, but these colours also appear in skin cream, foundation, mascara and so on too. (Remember also that these colours can also be in 'natural' cosmetics and skin care products.)

Another worry is that even the 'experts' cannot agree on an international 'safe' list of colours, so that a colour may be allowed in one country, but banned elsewhere. For example, quinoline yellow is allowed within the European Community and in some other countries, but is banned in Japan, Norway and the United States.

As ever, the advice is: keep yourself informed and read the label. Here is a list of the different names and numbers that common colourings go under:

Tartrazine: E102 or FD & C Yellow 5 or C.I. 19140 Quinoline yellow or E104 or C.I. 47005 Sunset yellow or E110 or FD & C Yellow 6 or C.I. 15985 Amaranth or E123 or FD & C Red 2 or C.I. 16185 Ponceau 4R or E124 or C.I. 16255 Erythrosine or E127 or FD & C Red 3 or C.I. 45430 Red 2G or E128 or C.I. 18050 Allura red AC or E129 or FD & C Red 40 or C.I. 16035 Patent blue V or E131 or C.I. 42051 Indigo carmine or E132 or FD & C Blue 2 or C.I. 73015 Brilliant blue FCF or FD & C Blue 1 or C.I. 42090 Fast green FCF or FD & C Green 3 or C.I. 42053 Green S or E142 or C.I. 44090