Document wrp5rM6gQo1wO2n30yayg9R0B

February 7, 1967 Mr. D. L. Parker Dawborn Division W.R. Grace & Company Waynesboro, Virginia Dear Mr. Parkert During our conversation last week, you requested iefosiietion on air analysis for the determination of^Aroc^or n.260/ln air. A description is given in the attached reprint. As you can see, this deals with Aroolor 1242 and 1254. These are diphenyls chlorinated to the respective percentages, as indicated by the last two numbers. Aroclor 1260 has a higher \ chlorination. We are certain that if air concentrations are 7. kept to the threshold limit Of 0.5 mg./cubic meter, no ** hazard is to be expected. I repeat what I have told you, that with the exception of in stances where prolonged breathing of the fumes evolved at high temperatures occurred, we have had almost no complaints referable to systemic damage. Care must be taken, however, V in engineering the installation. Local exhaust ventilation \ should be provided if Aroclor fumes are evolved during the j process. If you have any further questions, please let me know. Sincerely, REK/ln att. R. Emmet Kelly, M. D. Medical Director DSW 018242 STLCOPCB4004787