406 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS procedure. I still believe that the method using radioisotope labelling, for example, is a very much better way of determining the absolute amount involved. Now if we analyse what one learns by the experiment that has just beerr presented, it should be emphasized first of all that we have known for many years what happens to PVP, for instance, when it is introduced into the body. PVP was used as a plasma substitute during the last war and subsequently very large amounts were infused, so we do know that it is a macromolecule• that it is taken up by the reticuloendothelial system, that it tends to be cleared from certain organs and transported to others such as the spleen• and all these phenomena are pretty straightforward. So the slides that have been shown on the screen, while very elegant and beautiful, do not really' add to what one would expect, namely, that a part of the material inhaled would be phagocytosed by alveolar macrophages, would be transported to lymph nodes, would eventually be cleared from certain organs such as the lung and taken to the spleen. What is important when one is thinking in terms of 'thesaurosis' is the reaction to the stored material, not the presence of the material, which I think is relatively unimportant. What Bergmann et al (9,10) have always. stressed on thesaurosis is the reaction, the very serious pathological changes which were supposed to ensue after the material had been stored. I would be very interested to hear whether detailed histopathological studies• have been carried out, and whether any such pathological changes have been observed to follow ? Another very important aspect is the suggestion that stored material,. like PVP, elicits a local effect which is manifested by the development of a positive periodic acid-Schiff (PAS) reaction in the tissues. This is very important because as Brunner et al (11) showed, one may obtain a positive- PAS reaction in tissues of people who lived long before hair sprays were ever invented, and therefore it would be of very great interest to us to know whether in these particular experimental animals this reaction was carried out and whether it was found to be positive ? The most recent development in this country, as far as thesaurosis is. concerned, has been the work of the M.R.C. unit who, in addition to carrying out a survey on a large scale, did discover one case of what appears to be sensitization to shellac (12). This was a very severe pulmonary syndrome• (9) M. Bergmann, I. J. Flance and H. T. Blumenthal New Engl. J. Med. 258 471 (1958)• (10) M. Bergmann, I. J. Flance, P. T. Cruz, N. Klam, P. R. Aronson, R. A. Joshi and H. T. Blumenthal New Engl. J. Med. 266 750 (1962). (11) M. J. Brunner, R. P. Giovacchini, J.P. Wyatt, F. E. Dunlap and J. C. Calandra J. Am. Med. Assoc. 184 851 (1963). (12) A. I. G. McLaughlin, P. L. Bidstrup and M. Konstam Food and Cosmetics Toxicology' 1 171 (1963).

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.