198 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS that preservative systems inactivating high dosages of test microbes are adequate under production conditions. ACKNOWLEDGMENT The author gratefully acknowledges the assistance of the following co-workers in the preparation of this paper: Mr. Aaron Efron, Chem- ical Engineer Mr. Carl Fraction, Microbiologist and Miss Barbara Warncoke, Secretary. (Received September 20, 1966) REFERENCES (1) Wedderburn, D. L., Hygiene in manufacturing plant and its effect on the preservation of emulsions, J. Soc. Cosmetic Chemists, 16,395-403 (June, 1965). (2) Foster, E. M., et al., Dairy Microbiology, Prentice-Hall, Inc., New York, 1957, pp. 97. (3) Hollaender, A., Radiation Biology, Vol. II, McGraw-Hill Book Company, New York, 1955, pp. 55. (4) Luckiesh, M., Germicidal, Erythemal and Infra-red Energy, D. Van Nostrand Co., New York, 1946. (5) Koller, L. R., Ultraviolet Radiation, 2nd Edition, John Wiley and Sons, Inc., New York, 1965, pp. 236-256. (6) Cruickshank, O. A., and Braithwaite, D. O., Sterilization of cation exchange resins, sulfonated phenol formaldehyde type, Ind. Eng. Chem., 41,472 (1949).

J. Soc. Cosmetic Chemists, 18, 199-203 (Mar. 4, 1967) Techniques for Evaluating Dermal Irritation ANNE WOLVEN, B.S., and IRVING LEVENSTEIN, Ph.D.* Presented May 10, 1,966, New York City Synopsis--The use of Sulphan Blue (sold as Alphazurinine 2 G) is an aid in visualizing the response of rabbiCs skin to mild irritants. In as short a period as one hour skin changes may be observed. Sulphan Blue can also be used as an aid in the visualization of those materials which induce photosensitivity in the guinea pig. INTRODUCTION In developing a preparation to be applied to the skin the cosmetic manufacturer must take into consideration the factors of public ac- ceptance and safety. In most cases the elegance of the finished product is the deciding influence in its promotion. The possibility of any ir- ritating effects that this product may have on the skin, either because of its final composition or because of one of its many components, is of equal importance. Since the use of these products is widespread and the usage directions are very general, it is of great importance that the introduction of a new preparation shall produce no irritation even in one individual in ten thousand. In order to check the innocuoushess of a new preparation animal test methods are utilized in the laboratory. Patch testing techniques employ the rabbit or guinea pig as the animal of choice. The time of application of the test samples is purposely lengthened to magnify the extent of reaction that may occur. * Lebereo Laboratories, 123 Hawthorne Street, Roselle Park s N.J. 0_7204• 199