326 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Category C.-Ext. (i) Chlorinated phenols in concentrations of about 0-25% are said to be effective, but there is doubt about their safety. (ii) Formaldehyde in concentrations up to 0.05% is effective and accept- able. Some other compounds, e.g. paraformaldehyde and 1-hydroxymethyl- 5-5'-dimethylhydantoin which liberate formaldehyde might also be con- sidered. The permitted content for each compound must be controlled so that the amount of free formaldehyde evolved does not exceed 0.05%. Category C.-W.R. Phenylmercuric salts are tolerated only in shampoos within certain concentration limits, and the label should include instructions to rinse carefully. Colours At present the only colours completely acceptable in Category C are the approved food colours, but many others used in lipsticks must be provision- ally accepted. These further colours, which are said to be indispensable to give the range of colours required, should be tested biologically within 5 years. For dental products (including toothpastes) the food colours and, on a provisional basis, Rose Helindone (CI 73360) and Alizarin (CI 58000), only should be allowed. In certain instances, e.g. fluorescein derivatives, limitations must be placed on the use, or on the proportions used. For Categories C.-Ext. and C.-W.R. no positive lists are required and negative lists only are recommended. Manufacturers will thus use on their own responsibility any colours available for these purposes, except the colours designated in the negative list. Surface active agents Surface active agents are long chain amphiphilic derivatives which alter interfacial tension, and include artionic agents used for cleansing and as emulsifiers, non-ionic and amphoteric agents used mainly as emulsifiers in creams and lotions, and cationic agents which are anti-bacterial. Chronic biological tests using both oral administration and skin applica- tion, conducted with the major anionic surfactants, among which are soaps, alkyl sulphates, alkyl benzene sulphonates, alkyl glyceryl ether sulphonates, lauryl trioxyethylene sulphate and alkyl benzene ether sulphonates, have

PREVENTION OF HAZARDS FROM CHRONIC TOXICITY' OF COSMETICS 327 indicated the absence of chronic toxicity including carcinogenic activity in these substances. Similar tests have also been carried out on certain non-ionic surfactants used as emulsifiers. These showed no toxic effects at reasonable dosage levels by mouth, but when applied topically, certain of these substances have been found to promote the formation of turnours in mice and rabbits after the application of a known carcinogenic initiating agent. As similar results have been found with sodium stearate, there is need for a clearer understanding of the significance of these experiments and their extension to include a wider range of surface active agents. The 5th Report of the Joint Expert Committee of FAO/WHO entitled "Evaluation of the Carcino- genic Hazards of Food Additives" states: "It has been demonstrated, under certain experimental situations, that carcinogenesis may be a two-stage process involving an 'initiator' and a 'promotor' which may be separate agents. This aspect of carcinogenesis is so far insufficiently understood or generalised to be considered in the present practical context." The demonstration that a substance has a promoting action should not, in itself, justify its exclusion from cosmetic formulations. For surface active substances, not only the individual toxicity but the effect of surface active substances on absorption by the skin of accompanying substances must be considered. Testing should be directed toward the evaluation of complete products as well as of the individual constituents. The published and unpublished evidence on the toxicology of surface active agents should be reviewed for the purpose of developing a list of substances considered unsuitable for use in cosmetics. Hormones Until more evidence is forthcoming, the female sex hormones should only be permitted for use in cosmetics under Category C.-Ext. if the label bears clear statements on the following points: 1. Official name of hormone and full formula of products. 2. The concentration expressed in International Units and this not to exceed 350 I.U. per g. 3. For use only by women over 30 years of age and never more than 15 g of the preparation per week. 4. Not to be used while handling infants and not to be applied to the skin of children.