66 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS NATURAL PRESERVATIVES Anthony C. Dweck Research Director, Peter Black Medicare Ltd., White Horse Business Park, Aintree Avenue, Trowbridge, Wiltshire, UK. BA14 OXB INTRODUCTION The subject of natural preservatives is one that probably has more academic interest than practical or economic virtue. However, it does have a marketing angle which may justify the higher raw material costs. LEGAL POSITION No preservative may be used which does not appear in:- Annex VI Part 1 or 2 of the EEC Cosmetic Directive 76/768/EEC - including 19th. amending Commission Directive 94/32/EC. However, there is no legislation for those natural materials, which, when used for their beneficial effect on the skin, may coincidentally have a positive effect on the total preservative requirement of the formulation. Of course, no material appearing in Annex II may be considered. SUGAR High levels of sugar can preserve against spoilage organisms, this may be seen in jams, preserves, certain sweet pickles and marmalades. This is also an important factor in the preservation of boiled sweets and chocolates etc. Increasingly, it will be noticed that many products now have to be kept in the refrigerator of freezer once opened, because sugar has been replaced by artificial sweetener which is cheaper and healthier(?) to eat, but which compromises the self-preservation of the product. HONEY Honey in its undiluted form is also a natural preservative and, indeed, there are many learn6d papers citing honey as a viscous barrier to bacteria and infection. ALCOHOL Not all organisms are bad! The production of alcohol from sugar by yeast is an industry in its own right. A wine carefully produced using sterilised equipment and fermented to 13% by volume will just about resist further infection from external organisms, once the ferment has completed. It is during the time of the fermentation process that the fermenting must is vulnerable to infection. The naturally produced fermentation grade alcohol can be concentrated by distillation and used as a natural preservative in toners, aftershaves and colognes. HEAT Heating, cooking and pasteurisation is another natural form of preservation that will sterilise products, especially where that product is designed as a one-shot use product - for example, a phial or a sachet. Alternatively, once opened, the product can be stored in the fridge of freezer to prevent microbiological degradation. DESICCATION Removing water from a product or making it totally dehydrated will greatly reduce the possibility of spoilage however, it must be recognised that the presence of spore-bearing organisms could become active once that water is reintroduced. ANHYDROUS In a similar vein, one could make products with materials that do not contain any traces of water, i.e. to deliberately design and formulate a totally anhydrous product. However, creams that can be finished by the consumer, by introducing water to the blend of oils, fats and waxes are prone to the same restrictions as the dessicated products.

PREPRINTS OF THE 1997 ANNUAL SCIENTIFIC SEMINAR 67 SALT The use of extreme levels of salt as used by the ancient mariners to preserve their meat is effective and it very likely that the preservation of the Egyptian mummies was, in part, achieved by the 40 day treatment in natron (a concentrated brine solution that osmotically drained the tissues of water). COLD Placing a product in the cold merely 'stops the clock' on microbiological growth and this is perfectly fine, provided the product was sterile when it was placed in the cold and/or had sufficient preservative 'mass' to counter any new organisms subsequently introduced. ACID pH The preservative activity can be boosted by operating at as low a pH as possible. Natural acidity could be obtained from one of the many of the alpha hydroxy acids (AHAs) which are obtained from citrus species, where the major components are citric and malic acids. CHELATING AGENTS In addition to formulating at low pH, chelating agents such as femlic acid extracted from rice bran, could be added to enhance the activity of the natural preservative. ANTIOXIDANTS Antioxidants such as natural tocopherol and ascorbic acid will further aid in preservation, as well as reducing the potential rancidity. GLYCERINE High levels of vegetable glycerine, up to 15-20%, will also have a preservative effect, similar to that effect obtained by the use of high levels of sugar. PLANTS SELF-PRESERVATION Plants in the wild do not go mouldy, and yet they are in an environment that predisposes them to suffer from the infestation of all manner of spoilage organisms. Yeasts, moulds and bacteria abound in the soil. all working to breakdown dead plant material and provide fresh humus for those plants living in the soil. Living plants resist the natural forces of disintegration. The process of protection is achieved through chemical entities present in the plant, which if extracted carefully can be a source of natural preservatives. REFERENCES 1. Dweck, A.C.: Natural preservatives. Part 1. SOFW Journal 1995, 7, 490-495 2. Dweck, A.C.: Natural preservatives. Part 2. SOFW Journal 1995, 9, 673-681 FREQUENCY OF USE OF PRESERVATIVES IN THE UNITED STATES, 1996 By David C. Steinberg Steinberg & Associates, Inc., Plainsboro, NJ 08536 Introduction In the United States, The Food and Drug Administration (FDA), is responsible for the regulations of cosmetics. In general, the industry is serf regulated, as the FDA works on a "negative" list bases. That is, you can use any ingredient in cosmetics, unless the FDA specifically prohibits the use of the ingredient.