INHALATION AND TOXICITY STUDIES 407 perhaps approximating to the sort of cases that Bergmann had described. I think it would be of great interest to know whether in the experiments carried out by you, there were any effects on pulmonary function of the animals and whether the aspect of sensitization was investigated. TI• L•CTUR•R: I am pleased at your interest in the results of our investi- gations. In principle, I agree with you regarding the difference between qualitative and quantitative assessment. As our results prove, the question of whether the hair spray applied by us causes thesaurosis could be denied clearly by means of the fluorescence-microscopic method we have used. So far as methods of quantitative assessment are concerned, further interest- ing contributions relating to the inhalation of aerosols are to be expected. Such methods, however, were not necessary for dealing with our problem. In principle, I agree with you that the sequels, i.e. the reaction of the organism to storage, is of greater importance for the assessment than the storage as such. As we could prove that there is no storage even after chronic action of relatively large doses, no sequel can be expected when the cause is missing. I am grateful to you for pointing out that PAS-reactions in human tissue had been detected long before hair sprays were invented because this fact constitutes a contribution to the unspecificity of the PAS-detection for shellac. DR. L. Go•.•RG: I would point out that on the question of intake into. the lung, the determining factor is the particle size. Provided you have a substantial proportion of particle sizes in the respirable range you do not have to carry out experiments to demonstrate that the material can reach the bronchioles and alveoli of the lung you can assume that. TI• L•CTUR•R: The opinion still prevails that the particle size of hair sprays does not permit an intake into the lung. There are two ways of settling this question: The physical determination of particle sizes and the examination of the lung, as carried out with our fluorescence-microscopic method and by means of which, in our opinion, we clearly proved that the. basic particles get into the lung but are not stored there. DR. L. GOL•RG: What about the question of PAS-positive or other reaction round the particles ? TI• L•c•uR•R: No PAS examinations were carried out, because we are- of the opinion that this is not the appropriate method. DR. L. Go•.•Rc,: We all accept that it is not an appropriate method for PVP, but it is a question of whether there is local production of acid muco- polysaccharides and similar substances which is the body's reaction, the reaction of the macrophage to ingested material.

408 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS THE LECTURER: Further investigations showed no sign whatsoever of •changes caused by the intake of basic particles. DR. L. GOLBERG: What about sensitization ? THE LECTURER: Our tests lasted 140 days and we used quantities far in .excess of what one would expect to meet in practice. We did not observe any hints of sensitization on hamsters, rabbits or monkeys. DR. L. GOLBERG: The reason why I harp on sensitization is not only this particular case to which I referred but when one reads the original papers of Bergmann et al (9,10)--assuming that there was a connection between the cases he described and the inhalation of hair spray--all these changes in the lung, the interstitial fibrosis and other histopathological changes, ! think, point not merely to storage. The whole question has been bedevilled by the use of this word "thesaurosis" which I think was a misnomer in the first place. It is not really storage that is important, it is the reaction, and this may be considered in some respects as a hypersensitivity response. That is why this avenue of approach is still of importance but, of course, how one can elucidate the problem on an animal basis is a very difficult question. THE LECTURER: I agree that the problem of sensitization is one of the most difficult. •IR. T. HARRIS: How do you know that the fluorescent areas seen under the fluorescence microscope are due to the presence of polyvinylpyrrolidone and not to the fluorescor itself ? If, on the other hand, the fluorescence is given by a PVP/fluorescor .complex, then the rate of disappearance of the fluorescent particles will not, strictly speaking, be properly related to the PVP, as the physical properties of the latter will have been appreciably changed. THE LECTURER: We have carried out basic experiments which convinced us that these are in fact PVP particles. Unfortunately I am not permitted to go into details. MR. A. W. POND: You said that the hair spray particles had disappeared .after 3-5 days. Had they disappeared just from the lungs or from the whole organism, i.e. had they been transferred to other organs such as the liver or spleen ? Inhalation studies and histopathological studies have been carried out in the U.S.A. on hair sprays most of which have contained water-soluble of water-dispersible film formers. On the other hand, the M.R.C. mass radiography checks have been done on hairdressers most of whom will be using shellac-based sprays.