Document 70X68LjGqKjbjLadaZV5p4ao

8t. Eoule, Missouri Sr. H. R. Hainan Newport Or. J. W. Barrett - Lot.dui. Mr. F. 0. BenlyriuB-RuOerU Bui id L-; Dr, J. A. Gardner - Loriu.i. Oct. 1--3. 1--91.5 $sDMDsrrr:.., W. E. V. . E. A. Honor - Ruebon Hardy - Ann ittor. Hayward-St.Loul: Dr. H, NoO. Horgan-Fulioc r, JEixiland OCT 13 1955 Dear Harold) In redln,~ over the latter which yJ fcr>ujjht to the State* rasardlni! MCL pr>duata,and Dr. K*:!y a rep'y, I note that we did not elear tap eeapletely tha queetlon of a maximum allowable concentration for Aroclora. Joe Troon (of Kettering Tabs) oailed m today to clear several stateaents he wee coins te Include In a paper an his Aroelor Inhalation studies, the paper will probably be presented at the April, 1956 Industrial Health Conference in Fhlladelphle and will ba publlahad subsequently. Based an the enlantl results, Joe and Z agreed that he ahould propoae a suggested maximum allowable concentration for Aro elor let? of 2.0 nllllgreas per euble aster of air. In the ease of Areolar 125^. the n.e.e. of 1.0 ng. per euble aster will be prepoeed. You will aee by the oarben espy af ay letter to Dr. Stokinger that Z have forwarded to hia a eopy of freon's reports. You will resell that Z told Stokinger that Z hoped that the Com mittee of the Aaerlean Conference af Oevemaental Industrial Hygtanlete which establishes, reviews, and revises maximum allowable eoneentratlcna would review Troon' reports. Ferhaps then the CoMlttee will aeeept the proposed a.a.o.'s for 1842 and 1254 end publish than la place af the present listing of "chlorinated diphenyl,a.a.c. af 1 allligrea per euble aster." Z heps that ICL will act Interpret Traon'e results la such a faahlea that a.a.e. valuta lower than those ladloated shove are ever aentloned la public la Orest Britain. In Dr. Hardy's mm te you dated September 4, 1955. ha pointed out that per haps the a.a.e. for Areolar 1254 ahould be 0.15 allllgraao per euble aster. Although It is acanon te use a safety faster of 10 la traaepeelag ewe levels for aniaals te ears levels far humans, n da aot feel that sueh a safety factor la necessary with the Areelers. If the Aroelers were new preduets with limited use and handling experience, if there bad been reseat eases of llineea la workers exposed to these aaterlala, or if treen'e week had been lass axtaaalve, than we weald agree that the exposure whlah caused as effects la aalaala might be tee high for huaans. Ihla Is net the ease, however. Another HONS 090543 Br. I. ft. Iwin -- Page 8 Ootober 13. 195b factor whlah relataa to our conclusion# arc the results of tbs experlnent* Mbere the anlaale ware subjected to nearly saturated saner ecneentratlens for lose than 150 days with relatively little pathology . | heye your return trip was pleasant and uneventful. It Mens nighty quiet bore after the busy fortnight ellnexcd by your departure from St. Louis. With best regards. Sincerely. EPWiSMB Cheer t. Wheeler HONS 090544