PHYSIOLOGICAL PROPERTIES OF PROPELLANTS 345 Ullmann a mentions that 0.5% by volume may be inhaled for many hours without danger, and that 5ø,/0 by volume causes a slight numbness. These data have been confirmed by tests on animals for a period of 100 days, per- formed at the Battelle Institute, in Frankfurt/M. The tests included mice, rats and guineapigs, and the three propellants vinyl chloride, mixtures of propellant 11/12 50:50 and 10:90, and the three concentrations 0.5, 1.5 and 5.0% by volume. Including the controls, 120 animals of each type, in groups of 10 (5 male, 5 female), were exposed 2 hours daily for 100 days to an open inhalation system. Care was taken to ensure a constant air flow (physiological oxygen importation) in the cylindrical inhalation cham- bers. During the test period, the animals were fed with normal food, and they were weighed weekly. The tests indicated the following results: (a) The test animals showed no reactions to the inhalation of the propellant 11/12 blend. No deviations from the normal conditions appeared up to 1.5% by volume of vinyl chloride. An inhalation of 5% by volume of vinyl chloride first of all increased the mobility of the animals, and then reduced it as the tests progressed. The reactions were reversible. (b) The growth function was not influenced at all. (c) The blood pattern of all animals was normal. (d) There was no disturbance of the liver. (e) The autopsy of all test animals, and the histopathological examination of parts of the•n, showed no morphological determinable changes in the examined organs. Schade 4 confirmed these results in his experiments with 0.5--5.0% by volume of vinyl chloride. Hence 5% by volume is below the concentration which causes disturbances to the sense of balance (equilibrium), a state which precedes anaesthesia. These results do not agree with the findings of Torkelson 5. The obvious assumption is that the liver injuries which have been detected on anirnals, are due to impurities in vinyl chloride. The vinyl chloride, tested by us, was of the highest chemical purity. Another test carried out with a shellac-based hairspray utilising the pro- pellant vinyl chloride 6 gave the same results as that with propellants 11 and 12. Three groups of white mice beneath a plastic cover were sprayed for 30 seconds daily, for 5 weeks, from a distance of 20--25 cm. The animals were closely observed, and dissected after the test. No changes could be discovered. No inflammation phenomena in the bronchials, lungs alveoles and the bronchial lymphknots were present. This is of particular signi- ficance in view of the present hairspray-thesaurosis controversy.

346 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Shepherd's view 7, that small quantities of vinyl chloride have an anaesthetic effect, could not be confirmed. Like Hoffmann 8, no reference to the litera- ture was given. The anaesthetic concentrations of fluorohydrocarbons 11, 12, 113 and 114 have been examined by Scholz 9. Rats and guinea pigs were exposed to increasing concentrations by volume, with the air circulating in a closed room. Carbon dioxide was absorbed, and the oxygen content was kept at a constant level. Rats and guineapigs behaved differently. Table 2 Anaesthetic concentrations for rats _Propellant Condition Concentration Time % minutes 114 G 30 120 1N 50 120 tN 60 120 T -- -- -- 12 G 30 120 1N 50 60 tN 60 60 r -- -- 113 G 10 30 1N 15 15 tN 20 20 T 20 45 11 G 5 40 1N 10 20 tN 10 90 T 20 5 G - disturbance of equilibrium 1N - slight anaesthesia tN- deep anaesthesia T - death. According to Scholz these results just about agree with American data. In addition, propellant 11 was compared with chloroform and carbon tetra- chloride. With cats, already an exposure for one hour with approximately 1.5% chloroform and approximately 2% carbon tetra chloride has a lethal effect with propellant 11 an exposure with 10% by volume for one hour is necessary in order to obtain a lethal effect. Scholz also explains, that such high concentrations (by volume) which were used for these tests, are not achieved when spraying from pressurized packs. In any event, mixtures of propellant 11 and 12 are mainly used. The tests carried out in the Battelle Institute confirm this insofar as a mixture of 2.5% by volume of propellant 11 and 2.5% by volume of propellant 12