Document 4vdLe1kVrppRQZKpxMZ6a6r5Q

environment Hhoto Th*AnHr* CWb' MLIJDKFli^Q In torn* rlvtrt It partied by level* of PCS* that exceed limit* aet by FDA. problem for all parties fy'r* spreading in environment despite Monsanto's cutbacks; EPA says toxic substances bill needed for effective control Chemictl companies, electrical equip* ment makers and government regulatory agencies are frustrated over polychlori nated biphenyls. So far no viable substi tutes have been found for the nonflam mable heat-transfer fluid. But, although the sole U.S. manufacturer, Monsanto, hus restricted use of the chemical to closed systems, such as transformers and capacitors, more of it is appearing in the environment, and regulatory agencies say they have no tools to control its spread. The frustrations spilled over at the En vironmental Protection Agency meeting on PCBs in Chicago recently (CtF Technohffy Newsletter, Nov. 26). EPA re ported that some 10 million tbs. of the chemical are "lost into the environment each year through vaporization, leaks and spills.'' Bui EPA Administrator Russell Train said he was reluctant to ban PCB discharges under Section 504 of the 1972 Federal Water Pollution Control Act Amendments, but could go along with a l-part/trillion water-quality limit. Train indicated that PCB discharges could be controlled only after piissage of toxic sub stances control legislation now pending in Congress. Stressing the impact of PCB spills on Osh. Nathaniel P. Reed, an Assistant Sec retary of the Interior Dept., said the na tion's rivers and lakes were "in mortal danger," with levels m fish in excess of the Food and Drug Administration's 5*ppm. limit "virtually everywhere." Reed's solution: limit PCBs to trans formers and capacitors. But Monsanto has already done that. And the frustrated electrical equipment industry hasn't been able to And a substi tute with the all-round coating, heattransfer and Are-resistance properties of PCB. Dow thinks it's on the right track with its alkylated chlorobiphenyl oxide (OK June 25. p. 43), which will get a big boost this week when McOraw-Edison (Elgin, III.), one of the major electrical equipment makers, says that it will switch to the Dow product for some of its ca pacitors. INo Authority: "We And ourselves with out the authority we need to really cope with the problems posed by PCBs," said Train. And Walter C. Barber, EPA's Director of Standards and Regulations Evaluation, expressed doubt that even tough PCB ef fluent slandards-expected to be drafted sometime this spring-can be effectively enforced because of the "apparent myr iad" of small sources of PCB discharges. A study reported by EPA chemist Thomas Kopp indicated that at least 10 electrical equipment plants were dis charging PCBs directly into waterways and that two others were discharging the chemical into municipal waste treatment systems. In Canada, where the PCB limit in foodstuffs is 2 ppm., officials have re ported an average level of over 17 ppm. 40 CHEMICAL WEEK December 3. 1975 in eels from the St. Lawrence, over 4 ppm. in smelt and about 2.3 ppm. in stur geon from (he river. Striped bass and salmon caught in the Hudson River and Lake Ontario had PCB levels of over 5 ppm., which leads New York's Environ mental Conservation Commissioner. Og den Reid, to warn against eating Hudson River flsh. "Under present conditions. PCBs may very well pull the rug out from beneath us by destroying marginal species in spite of our best efforts for preservation." said Interior's Reed. Persistent and Resistant: "The thing that makes these products Are retardant is the same thing that makes them persis tent," says Monsanto. F.W. Ruiz and S. C. Strassman of EPA noted an apparent increase in the per centage of people in (he U.S. whose tis sues had trace levels of PCBs between 1972 and 1974. They reported PCBk were found in 50.6% of the general U.S. popu lation sampled (1,047 samples). Between 1 and 3 ppm. were found in 314% of the samples, and more than 3 ppm. in 4.9% of the samples. But a key problem seems to be that no one is sure why PCBs are increasing in the environment with the production down (40 million lbs./year) and use lim ited. Surveys by the Michigan Dept, of Natural Resources--which has urged a ban on all but dielectric use of PCBs-- failed to identify any electrical appli cations as major sources of water con tamination. The Michigan study found plasticizer applications, including paper recycling, and municipal sludge in landfllls. from which the PCBs may be transported by air, as possible important sources. The re port cited hydraulic fluids as an impor tant past source and noted that although all known users of PCBs for hydraulic fluids have switched to substitutes, they continue to have PCB contamination. Substitute Search: Chemical com panies are still searching for PCB substi tutes for electrical applications. Mon santo is joining in the search but feels PCBs are indispensable for all dielectric uses. But McCraw-Edison appears to be sat isfied with Dow's research on its heattransfer chemical, although its use ap pears to be limited to capacitors. Other chemicals being tested for capacitors: di* isononyl phthalate from Exxon Chemical and dichiorobiphenyl plus its alkyl de rivative from France's Prodelec S.A. And for transformers, Dow Coming's polydimelhyi siloxane is being readied. HONS 032512