PREDICTIVE PATCH TESTING 331 critical level necessary to induce immunologic modification in the mesenchymal cells. Or repeated delivery of antigen to the nodes will be more likely to catch the cells at that point in their cycle of growth and division at which they are most susceptible to this modification by the antigenic substance. Returning to the practical aspects of the problem, perhaps the situa- tion can best be summarized as follows. Results of predictive tests as now constituted serve as guides rather than absolute criteria of sensitization and irritancy. The tests function best when the test substance is used on a comparative basis against control formulations with known be- havior in actual usage. Further study of the basic mechanisms of sensitization is required before the tests can be signi/Scantly improved. Alterations in current test procedures can increase or decrease the num- ber of reactors but do not help in answering the crucial question of the relationship between sensitization results in laboratory tests and in consumer usage. Properly supervised consumer use tests are still re- quired to supplement the laboratory studies. (Received September 21, 1966) REFERENCES (1) Draize, J. H., Woodard, G., and Calvery, H. O., Methods for the study of irritation and toxicity of substances applied topically to the skin and mucous membranes, J. Pharmacol. Exptl. Therap., 82,377-390 (December, 1944). (2) Finkelstein, P., Laden, K., and Mieehowski, W., New methods for evaluating cosmetic irritancy, J. Invest. Dermatol., 40, 11-14 (January, 1963). (3) Schwartz, L., and Peck, S. M., The patch test in contact dermatitis, Public Health Rept., '59, 546-557 (Apr. 28, 1944). (4) Brunncr, M. J., and Smiljanic, A., Procedure for evaluating skin-scnsitizing power of new materials, Arch. Dermatol., 66,703-705 (Dcccmbcr, 1952). (5) Cainan, C. D., Epstein, W. L., and Kligman, A.M., Methods of Evaluating Contact Sensitizers, in Stcrnbcrg, T. H., and Newcomer, F. C., Evaluation of Therapeutic Agents and Cosmetics, McGraw-Hill Book Co., New York, N.Y., 1964, pp. 157-170. (6) Shclanski, H. A., and Shclanski, M. V., A new technique of hmnan'patch tests, Proc. Sci. Sect. Toilet Goods Assoc., 20, 46-49 (1953). (7) Draizc, J. H., Derreal Toxicity, The Association of Food and Drug Officials of the United States, P. O. Box 1494, Topeka, Kan., 1959, p. 52. (8) Traub, E. F., Tusing, T. W., and Spoor, H. J., Evaluation of derreal sensitivity: Animal and human tests comparcd, Arch. Dermatol., 69,399-409 (1954). (9) Voss, J. G., Skin scnsitization by mcrcaptans of low molecular weight, J. Invest. Derma- tol., 31,273-279 (1958).

332 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Midwest Chapter 967 Program May June July, August September October 10 November 14 December No local meeting--National meeting, New York City Ladies Night No meetings No local meeting--Color Seminar, Chicago Dr. Aaron Miller, Kolar Laboratories--"Studies on the Reaction Rates of Hair Strengthening Agents with Hair" Mr. Henry Maso, President's Night. Installation of New Officers No local meeting--National meeting, Ne•v York City