SPRAY PATTERNS OF COSMETIC PRESSURE PACKS 455 The sprays obtained with these formulations, when sprayed through standard valves, are considered suitable for their intended purpose (Figs. 1A, lB). A possible drawback in the case of hair laquers, is the flammability rating according to the United States I.C.C. regulations, and possibly be- cause of this, the formulation 20 per cent product, 80 per cent propellant 11/12 (1:1) has been proposed for hair laquer (3). Undoubtedly safe so far as flammability is concerned, the spray obtained consists of very, very fine particles which can hardly be considered satisfactory for surface application, and there is a great risk of excessive inhalation of spray particles. In addition, over-spraying, i.e., spraying over an area larger than intended, could lead to damage of furniture, clothes and the like. Figure 2 (A & B).--65% ethyl alcohol :35% propellant 12. Value "A" standard actuator All these formulations suffer from the fault that they incorporate not only large amounts of expensive ingredients, i.e., the propellants, but also that one of the propellants (No. 11) could give rise to corrosion. The formula- tion 65-70% hair laquer, 35-30% propellant 12 is therefore more suitable if considered from the angle of cost and corrosion but totally unsuitable if used in conjunction with a standard valve having an ordinary actuator because a strong narrow jet, consisting of large particles results (Figs. 2A, 2B), despite the fact that the spray does contain liquid propellants.

456 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS If sprayed into a flame, a flame extension of 23 inches results and the drum tests are positive (4). If, on the other hand, a break-up spray actuator is employed then a wide angled soft spray with much smaller particles results, (Figs. 3A, 3B) which is acceptable, and which has also a better flammability rating. • •.• ..4,•.•.: • .v-:.:...•v ..... : '%4-..•.e • .. • • :.-• ..• 2 • .-9 .• . . • • • ...... • . . .•. •:... •..• '•. :. :• ?:: •-• •, ? • .... •.. •= } •-:'•.•:• {•½•:• •' :':•', •-. •.,•.X ½'•.•:* ' z.- • ' ':'.• "")*•" :•" ' ::.•:' ""' }-&• :" ' .... '": ....... •'.. '•-'.':.. .:.• .•:•. .., -.:m•. • 4 • .: x a ß ..•(::?•..,,,:., .... j:r. .. *•-.. ..•. Figure 3 (A & B).--65% ethyl alcohol, 35% propellant 12. Valve "A" break-up spray actuator. Variation in spray patterns are, however, obtained not only by changing from an ordinary actuator to a break-up spray actuator in any given proprietary valve, but also by using a different valve altogether. This is illustrated by comparing Figs. 4A and 5A, with 3A all spraying a mixture of 65 per cent alcohol and 35 per cent propellant 12. The changes in spray pattern effected by changing the valves applies to every formulation, but is particularly noticeable when the valve design itself has a bearing on the resultant spray, as occurs with the formulations mentioned above, or when using butane or chlorofiuorohydrocarbons with an aqueous product (3-phase systems), or when nitrogen is used as the propellant. With nitrogen, as with the 3-phase systems, there is no propellant at all in the emerging spray, which is very narrow and contains very coarse