TECHNICAL ASPECTS OF AEROSOL PACKAGING 363 packed aerosol for one month at 130 ø F., and if no corrosion occurred the pack was considered satisfactory. The results thus obtained were, however, not always borne out by subsequent product performance, and it would appear that more extensive tests are now recommended. 84 Our own experience has proven that in the majority of cases storage at 95 ø F. accelerates corrosion, see Fig. 5, but there are occasions when corrosion is retarded at that temperature. One particular formulation caused severe corrosion of the aerosol container, perforating the container within a week when stored at room temperature. The same formulation caused only slight corrosion in a similar container stored for eight months at 95 ø F. Roots• has recently suggested analysis of the contents of the aerosol container for iron and tin over a short storage period, as a means of accelerating approval of particular packs. Our experience with aerosol and other containers has shown that trace analysis of metal in the pack is no criterion of container performance. So far as I can see there is no safe short cut to the approval of aerosol formulations. Another important performance factor in cosmetic formulations is the spray pattern. A technique for determining this has been adequately described in the March, 1956, issue of this Society's journal.• Fig. 5. Aluminium Aerosol Container (no internal laquering) showing pitting due to unsuitable product formulation.

364 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS I sincerely hope that this paper will contribute towards your under- standing of the ever-growing field of pressurised or aerosol packing, and I wish to thank Mr. W. S. Manson, of the Cooper Technical Bureau, for the loan of slides showing various aspects of the PAFCO plant Mr. M. N. Conville, of Safca Aerosol Manufacturing, Ltd., for the loan of a slide showing the Satca filling plant Mr. W. C. Botfield, of W. J. Bush & Co., Ltd., for generously providing a quantity of the handcream formulation referred to in the paper last, but not least, my sincere thanks are due to the indefatigable Jack Pickthall, of Polak and Schwarz, for his many helpful suggestions. In conclusion, I record my thanks to the Directors of the Metal Box Co., Ltd. to Mr. R. K. Sanders, Director of Research, and to Mr. J. H. Brittain for permission to present this paper. REFERENCES • Shepherd, H. R., Amer. Perfum., Aug., 1954, 121. • D.R. Pat. 532,194. a D.R. Pat. 557,259. 4 Soap, N.Y., December, 1955, •tl, 209. * U.S. Pat. 2,321,023. 6 Reed, F. T., J. Soc. Cosmet. Chem., 1956, ?, 137. * Witjens. P.H. Private communication. 8 U.S. Pat. 2,705,661. • Mina, F. A., Drug Cosmet. Ind., 1956, ?8, 254. •0 Reed, F. T., KTM-18, "Kinetic Chemicals Division," E. I. du Pont de Nemours & Co., Inc., Wilmington, Del., U.S.A. n KTM-17, "Kinetic Chemicals Division," E. I. du Pont de Nemours & Co., Inc., Wilmington, Del., U.S.A. • Wells, F. V., Soap, Perfum. Cosrn., 1955, 28, 1271. •a Poole, J. J., and Steuernagle, J. H,, "Glass Containers as Packages for Low Pressure Aerosols," Brockway Glass Co., Inc., Brockway, Pa., U.S.A. •4 Verpackung Rdsch., 1956, 7, 122. •* U.S. Pat. 2,686,081. 2• Mod. Packag., November, 1955, 29, 98. 27 Br. Pat. 740,635. is Herzka, A., Chem. andInd., 1956, 6. 29 Aerosol News, 1, 4, "Kinetic Chemicals Division," E I. Du Pont de Nemours & Co., Inc., Wilmington, Del., U.S.A., •.o The GivaudanJan, April, 1955, 3. • The Givaudanian, May, 1955, 9. •' The Aerosol, Polak & Schwarz (England), Ltd., Enfield. •a Aerosols, N.V. Chemische Fabriek "Na•.rden," Bussu m, Holland. •.4 Pickthall, J., Parf. Cosmalt. Sayohs, No. 121, March, 1956, 85. 2, van Beem, J.G. Private communication. 2• Ruys. A. H. Private communication. •? Silicone Notes G6-1, March, 1955. Midland Silicones Ltd., London, W.1. •8 Curfie C. C., and Gergle, R. C., Soap, N.Y., January, 1956, $2, 98. •9 Philips, H. G., Jnr., Drug. Cosmet. Ind., 1954, 75, 30. s0 Greenfield, I., Indust. Chem. Mfr., 1956, $2, 11. sx Schimmel Briefs, N. Y., No. 233, August, 1954. as Drug. Cosmet. Ind., 1956, 78, 383. aa Perfum. Essent. Oil Rec., 1955, 46, 350. a4 Soap, Perfum. Costa., 1955, 28, 1117. a• Root, M. J., J. Soc. Cosmet. Chem., 1956, ?, 162. s0 Root, M. J., J. Soc. Cosmet. Chem., 1956, 7, 153.