Document evXEQd2X59kvw9wpvaoMLvro9

December 23, 1968 Nr. Paul W. McDaniel Union Carbide Corporation 270 Park Avenue New York, New York 10017 Dear Paul: Enclosed is one of our technical bulletins describing the series of Aroclor compounds. The chemical and physical properties appear on pages 42 and 43. Enclosed also are two copies of Joe Treon's publication discussing the chronic and inhalation studies with Aroclor 1242 and Aroclor 1254. You will note that for these two materials he suggested TLVs of 2 mg per cubic meter and 1 mg per cubic meter, respectively. The ACOXH cut these in half. _ As X told you on the phone, we do not have chronic inhalation data for Aroclor 1268. Comparative acute and 20-day skin application data for all three of the Aroclors mentioned above are summarised on the attached page. These numbers indloate that rats are more resistant to the chlorinated biphenyls and that lh oil solutions or suspensions absorption through the skin becomes significant. The 'limits' make it obvious that few animals were used. For example, in the 20day work there were only two rabbits per level and four dosage 1levels. Putting all of this information together leads to a conservative TLV for Aroclor 1268 of 0.5 mg/kg. A comparison of the distillation ranges of 1254 and 1268 would make it appear that the "hazard'1 for 1268 should be less as compared to the 1254. MUNS 090369 Mr. Paul W. McDaniel -2- December 23, 1968 For what It la worth our files show no reports or complaints of difficulties with Aroclor 1268. I am net sure, however, that there have been many applications where there might be exposure for personnel because the product was used at high temperatures. X hope you will have a very happy holiday season. Best regards. Sincerely, EPW:c J 8 Enclosures Elmer P. Wheeler Manager, Environmental Health mows 090390