720 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Preface In December 1967, the Society of Cosmetic Chemists of Great Britain and the Toilet Preparations Federation set up a Select Committee of three members of each body with the following terms of reference:-- "To investigate and report upon the desirability and/or advisability of recommending legislative control in the interests of public safety, as to the ingredients in and composition of toilet preparations and the uses for which they are promoted and to recommend the form and nature of such control, bearing in mind, in addition, international harmonization of such control." The Committee completed the production of a Code of Good Practice early in 1970. The original text of this forms Appendix A of this monograph. The Select Committee will be publishing an appendix to the Code setting standards for hygiene and microbiological safety, and may amend these from time to time. Readers are urged to obtain a set of these as soon as they are available to use in conjunction with this monograph. As the Select Committee felt it was not appropriate for it to give guidance on methodology, the Society of Cosmetic Chemists of Great Britain are publishing this monograph as an aid to their own members and to any other interested scientists in ensuring adherence to the standards laid down from time to time in the Code of Good Manufacturing Practice.

HYGIENIC MANUFACTURE AND PRESERVATION 721 1. INTRODUCTION 1.1 The problem of manufacturing hygiene Every responsible person concerned with the manufacture of toiletry and cosmetic preparations is aware of the need for clean operating condi- tions. The need to include a preservative in order to prevent microbial spoilage of susceptible products is also universally accepted. Good hygiene and efficient preservation call for detailed consideration of many complex factors. This monograph, prepared by a working party on behalf of the Society of Cosmetic Chemists of Great Britain, has been ratified by the Council of the Society. It is a guide to assist in solving the various problems likely to arise. Fortunately there is little evidence that actual harm has ever been experienced by users in consequence of infection transmitted by a cosmetic or toiletry product. Nevertheless, complacency could be dangerous. Microbial deterioration does not always give rise to obvious changes in a product and identification of the source of skin infections is often difficult. The importance of recognizing and excluding product contamination is underlined by the fact that many species of micro-organisms once believed to be harmless are now known to be capable of assuming a pathogenic role. It is therefore incumbent upon the manufacturer to institute an adequate routine of microbiological quality control. Monitoring the microbiological status of toiletries and cosmetics should preferably be accorded comparable importance to the control of chemical purity. These contentions imply that personnel adequately trained in microbiology should be available to the control laboratory establishment of a toiletries or cosmetics manufacturer. A microbiologist engaged in quality control should have adequate authority to discharge his duty within the provisions of the Code of Good Practice for the toiletry and cosmetic industry. Products under test for microbial contamination may need to be held for several days before release for sale. 1.2 Standards for microbial contamination If it were feasible to apply an unqualified requirement that every product should be sterile, or, in other words, totally devoid of living micro-organisms, the control problem would be relatively simple. Despite the theoretical attractions of this approach, however, it must be recognized that cosmetic preparations are not usually sterile and the achievement of such a standard would result in a great increase in production costs. There is no evidence that this would be justifiable in terms of any real additional