Document RpoD1rNRO3ogxpbzkdQdqrGQa

Industrial Hygiene Digest - 20 January, 1950 60 Air Contamination Standards. F.A. Patty . Standards Horld I, 57-62 (Autumn, 1949). . The standardization of permissible air contamination has proved to be a difficult task, for the following reasons: (l) scarcity of data on physio logical effects; (2) reluctance of committee members to agree an tentative figures because some States vill fix them In their codes; (3) fear that unnecessarily high limits vill be set; ami (4) the Inability of committee members to reconcile their vievpolnts. The author urges membership of a committee in harmony on the general purposes and Interested and qualified in' industrial hygiene and toxicology. He also suggests: (1) replacement of-the term "maximum allowable concentration" by "permissible concentration of air contamination," "safe practice standard," "hygienic standard" or some Blmllar term; (2) use of a range of concentrations as standard Instead of a definite concentration; (3) attempt to make a rare and reversible con dition rather than attempt the Improbable goal of complete eradication. Standardization on the basis of physiological effects Is difficult because side factors such as nutrition often play a part. In some cases permissi ble limits may be based on nuisance value and In others on sound engineer ing practice. Every standard should clearly Indicate its basis. Standards based on explosion control are simple and easily established. Standards, for outdoor pollution are Infinitely harder to fix than Indoor standards. 61 The Limitation of Exposure to Noxious Gases and Fumes In Industry. L.T. Falrhall. Ind. Hyg. Newsletter (published by U.S. Public Health Service) 10, 3-5 (January, 1950). In a general address on exposure to toxic materials and its prevention, Falrhall emphasizes Incipient poisoning. In addition to acute and chronic poisoning, as a factor to be considered and one that has not received ouch attention. In conclusion he points out; (1) that threshold limit values should be used only as guides In an evaluation of the vorklng environment; (2). that appraisal of the vorklng environment, so far as toxic aerial con taminants are concerned, requires especial care; and (3) that present thres hold limit values are subject to change and therefore should not be considered as fixed standards. 62 The Assay of Acute Vapor Toxicity, and the Grading and Interpretation of ,Results on 96 Chemical Compounds. C.P. Carpenter, H.F. Smyth, Jr., and W.C. Pozzani. J. Ind. Hyg. 8s Toxicol. 1 343-346 (Nov. 1949). The method used for grading the activity of a chemical on the basis of the response of rats to a four hour vapor exposure In a l4-day observation period is described. A list of 96 compounds that have been assigned to the various grades is given, together vlth a justification of the use of this method at the range finding level of toxicity study. -- Authors 1 Summary 63 High Concentration--Short Time Exposures and Toxicity. B.G. King. J. Ind. Hyg. fc-Toxicol. 31, 365-375 (Nov. 1949)-. The field of short exposure to high concentrations of toxic materials has had little study.- The author tabulates and plots the.data reported In the literature on concentration, time, and effects of carbon tetrachloride