Document DddM4Y5ErmB1V2gy2YZj1Va64

March 4, 1965 Mr. J. Cholak The Kettering Laboratory College of Medicine University of Cincinnati Cincinnati, Ohio Dear Jack: As I explained to you on the telephone, we are interested in getting a rough idea of the particle sizes resulting from the machining of Fiberglas-reinforced plastic forms. The machining operations are grinding or sanding, sawing and cutting. Me suspect that cutting creates a relatively small problem because very little dust is generated. At the moment, we are anticipating that manufacturers of FRP products will be asking about the particle sizes resulting from these machining operations for two reasons: (1) to determine the adequacy of ventilating or dust collecting equipment for such operations, and (2) whether or not the exposure to the dusts create a health hazard. Our Company produces practically nothing in the way of FRP structures so our own units do not provide much of an opportunity to collect samples of air-borne glass-plastic dusts. Customers are usually reluctant to approve air sampling activities around their working en vironments. This means, of bourse, that we must employ the next most satisfactory alternative which, in this case, was having some of our salesmen collect dust samples from available surfaces in the working areas. I realize that this approach is not very scientific and that it leaves a lot to be desired but perhaps we will gain enough informa tion to be of assistance to us. At least, we will know something more than we do now. Me do not attempt to answer any toxicological inquiries about plastic resins as we do not manufacture them. This, of course, is an obligation of the resin producers. Our primary interest is in the sizes of the glass particulate found in the samples although the sizes of resin particles would be of interest as a matter of comparison. Kf 0015348 Mr, J. Cholak 2 March 4, 1965 Incidentally, the per cent of glass in each sample may vary because it may run from 307. to SOX depending upon the kind of product. The resins will also vary. These data, unfortunately, are not avail able. I will have a total of about 10 samples for analysis and would like to get an estimate of the cost of determining the glass particle sizes contained in them. Because of the exploratory nature of this re quest, a rough guestimate is satisfactory and would be considered to be subject to revision when we formalize our requirements. Thanks for your help. Sincerely, FHEiJS cc: R. A. Kehoe, M.D. Kettering Laboratory Cincinnati, Ohio F. H. Edwards Health and Hygiene Department -KE 0015349