REACTION TO ARTIFICIAL COLOURING MATERIALS 223 DR. J. J. MAUSNER I WaS interested that you observed dermatitis to colouring material in lipsticks, face creams, powders, rouges, and other toilet preparations. The colouring materials used in these various cosmetics represent a very wide spec- trum of chemical composition. I would like to know whether you have been able to observe a common trend related to perhaps one particular colouring material through- out this range of products if not, could you state whether you were able to pinpoint the offending ingredient in powders? The main colouring materials used in powders are iron oxides as opposed to purely organic colours used in lipsticks and similar products. THE LECTURER: I have not noticed any special trend in these colouring agents in various preparations, except possibly with our textile dye work we think that the yellow dyes seem to be rather more dermatitic than others, for instance, in nylon stockings, hair nets and similar articles. I agree with you completely regarding powders. Most powders, where the colouring is usually from oxides, are not dermatitic at all. It is only occasionally when other organic compounds, lakes and so on are used that dermatitis is traceable to them.

J. Soc. Cosmetic Chemists 18 225-244 (1967) ¸ 1967 Society of Cosmetic Chemists of Great Britain The chemistry ß in cosmetics of synthetic dyes used J. c. BROWN* Presented at the Symposium on "Colour", organised by the Society of Cosmetic Chemists of Great Britain in Eastbourne, Sussex, on 27th April 1966. Synopsis--The recent literature on dyes for application to human hair is reviewed, including the use of oxidation bases and textile dyes. The chemistry of recently developed metal complex dyes for textile fibres, and their essential properties, are also discussed as many of these dyes are potentially valuable in hair dyeing. INTRODUCTION One of the most important and, technically most difficult, usage of dyes in the cosmetics field concerns the dyeing of living hair to aesthetically satisfying shades and there is an ever present demand for better techniques and new dyes in this field. The general literature on this subject appears to be somewhat limited (1) and the following comments are an attempt to survey some recent patent literature which has reflected an increased interest in hair dyeing by cosmetic manufacturers. The search for new dyes specifically designed for hair dyeing is being pursued mainly by firms other than the large textile dye manufacturers who tend to regard the quantities involved as insufficient to justify a research programme. At the same time, a number of new ranges of textile dyes have recently appeared which may well contain individual dyes of value in the dyeing of hair and in the colouring of cosmetics. An attempt will be made to describe some of these dyes, although commercial considerations unfortun- ately prevent a full discussion of their chemical structures. HAIR DYEING WITH OXIDATION BASES Oxidation bases are used extensively in the dyeing of furs in the leather trade where they are usually dyed with the assistance of a metal mordant •Ciba Clayton, Ltd., Manchester, 11. 225