Document 8Owq1m00dZ1R6oQQkv52xMO7e

E. f> Wheeler - Medical Department March 20, 1969 REPLY TO LETTER FROM SAN FRANCISCO REGIONAL WATER QUALITY CONTROL BOARD Tour memo March 12, 1969 F. B. Benignu Tom Ford Howard S. Bergen HSDRO FBENI TFORD I believe the following will aufflce for answers to questions 1, 2 and 3. 1. We have only recently contracted with a consulting laboratory to undertake fish toxicity studies. Due to the low solubility of polychlorinated biphenyl In water aa Indicated In four below it would not be surprising If we fall to get e 96-hour TI^,. Depending on the results of the Initial studies, we plan to do at least 30-day exposure experiments. We will keep you Informed or any results we Obtain. 2. There Is endowed a Xerox copy of two pages ahowlng the general physical eharactlstlca of our polychlorinated biphenyls. The numerical designation of the several products " la significant In that the 1200 series are biphenyls chlorinated to the extent Indicated by the last two numbers. For example, Aroolor 1242 la biphenyl chlorinated to the extent of 42. The 5400 compounds are terphenyls again with the last two numbers Indicating the percentage of chlorination. 4400 gild 2500 compounds are mixtures of biphenyls and terphenyls hlorlnated to the percentage Indicated by the last two . 'numbers. We have added to the '.bottom of these pages the results or aoate animal toxicity studies showing the oral ID50 In rets and the akin minimum lethal dose when applied to rsbblts. You will note that the saaples were adsdnlsterad undiluted or as solution-suspension in com oil depending ,on the viscosity and solubility of.the materials. ^ 3. Chronic inhalation data baa bean Obtained on Aroolors 1242 and 1254 and a reprliyt discussing the results of the studios is enclosed. The author suggests threshold limit values for an Industrial envlroment of s.o mg per\eu meter for Aroelor 1242 and 1.0 mg per eu meter for AroclVor 1254. The American Conference of Governmental Industrie1\ Hygienists dselded to raduoe those values by one-half. \ HONS 097997 Howard S. Burgen 2- Harch 20, 1969 You will not* in the table describing the properties of these materials that the liquid mashers of the series have extremely high distillation ranges and that waxy or reainoua members have to be distilled under high vaeuum. These data sttest to the low vapor pressure of the materials at ambient temperatures. Zn our more than 30-years of manufacture, cases of harmful effects in the industrial use of the materials have been extremely rare. He believe this is due to the low volatility which reduces any possible inhalation at ambient temperatures and aecondly the fact that in uses where the material Is .heated the system is a closed one so that exposures are limited to the occasion that when due to accidents the hot materials might escape from a system briefly. Where such incidents have occurred the irritation oaueed by the vapora from the hot materials have limited voluntary exposures ouch ttatsyetemic toxic effecta are rare. ca Bnolosures Xlmer P. Wheeler MQNS 09 7998