CONDUCTOMETRIC TESTING AND CORROSION STUDY OF HAIR SPRAY 157 merits) neutralized resin using AMPD were tested. No significant difference was found. The same results were obtained with Resyn 28-1310, 70% and 90% neutralized with AMPD. CONCLUSIONS It is evident that it is possible in most formulations to use 95% by wt. ethanol in combination with F-11 in hair sprays, if nitromethane is added as a corrosion inhibitor. The products obtained have the same shelf life as those containing anhydrous ethanol without the nitro- methane. Until the reaction between certain perfume components and nitro- methane in the presence of 95•o by wt ethanol and F-11 is thoroughly explored, it will be necessary to test every product to determine sta- bility. It was found that in some cases certain ingredients in perfumes have practically the same effect as nitromethane. In other instances, however, a reaction probably occurs between a particular perfume com- ponent and nitromethane, which can accelerate corrosion. The known effect on corrosion of the amount of air in the vapor space in a can with anhydrous ethanol (which plays an important r61e in contemporary hair spray products) is substantially minimized if nitro- methane is used. Conductivity, as a method of evaluating corrosion, proved to be very useful because of its numerical expression of results, and also for the ability to evaluate corrosion results of the product in the can, without opening' the can for visual examination. (Received April 18, 1967) REFERENCES (1) Root, M. J., Corrosion o[ aerosol metal containers, Proc. 42nd Ann. Meeting, C.S.M.A., Dec., 1955. (2) Johnson, H. T., McAlpin, A. W., and Schenck, A.M., S•me Aspects o[ Canning Soft Drinks, Food Technol., 12,643 (1955). (3) Root, M. J., and Maury, M. J., Corrosion testing of aerosol products, J. Soc. Cosmetic Chemists, 10,403 (1959). (4) Sanders, P. A., Mechanism o[ the reaction between trichloromonofluoromethane and ethyl alcohol, Proc. 46th Mid-Year Meeting, C.S.M.A., May, 1960. (5) Bower, F. A., and Long, L. J., Stabilization o[ alcohol-based aerosols, Proc. 47th Mid- Year Meeting, C.S.M.A., May, 1961. (6) U.S. Pat. 3,085,116, Stabilized chlorofluoroalkanes, D. E. Kvalnes and C. Ford, assignor to E. I. dupont de Nemours & Co., Inc. Patented Apr. 9, 1963. (7) Hoffmann, B., The question about the utility of nitromethane as stability agent in aerosol [ormulations, Aerosol Rept., 2• 17 (1963).

158 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS (8) Sanders, P. A., Nitromethane in aerosol formulations, Ibid., 2, 178 (1963). (9) Hoffmann, B., Nitromethane in aerosol formulations, Ibid., 2,182 (1963). (10) Hoffmann, B., The use of alcohols in aerosols, Ibid., 4, 71 (1965). (11) Sanders, P. A., Corrosion in aerosols, Soap Chem. Specialties, 43, 74 (July, 1966). (12) Sanders, P. A., Corrosion pitfalls in fornmlating aerosols, Proc. 52nd Mid- Year Meeting, C.S.M..4., May, 1966. (13) Reed, A. B., Testing for corrosion in aerosol packages, Ibid. (14) Johnson, H. T., Polarization methods applied to corrosion studies in aerosol products, Ibid.