Document mya18zZ25rQdmdaOKRbn9Z6J

BACKGROUND INFORMATION ON POLYCHLORINATED BIPHENYLS Office of Occupational Health Surveillance and Biometrics National Institute for Occupational Safety and Health November 3, 1975 DSW 323718 t i STLCOPCB4075279 .... L POLYCHLORINATED BIPHENYLS Introduction , Reports of adverse health effects in humans and the demonstration of carcinogenic effects in certain animal species have led to the reexamination of the distribution of polychlorinated biphenyls (PCBs) in the environment and the potential health effects of human exposure. Because the industrial environment represents the major source of potentially high exposures to PCBs, the National Institute for Occuptional Safety and Health (NIOSH) has gathered pertinent information on the manu facture, uses, and reported deleterious effects of polychlorinated biphenyls and is advising the occupational health community of these hazards. Background Polychlorinated biphenyls (PCBs) describe a group of synthetic chlorinated organic compounds having the following structure: zz z z where each of the ten Z's can represent either a hydrogen or a chlorine atom. There are two hundred nine different chlorinated biphenyls and they are collectively referred to as PCBs although many are not actually polychlorinated. Approximately half of these compounds have been synthesized and characterized. DSW 323719 STLCOPCB4075280 2- - . Mixtures of polychlorinated biphenyls are important industrial products. The most common tradenames for these mixtures are Aroclor, be d Inerteen, Kanechlor, and Pyranol. Other known tradenames for PCB- containing products are listed in Table I. PCB-containing dielectrics (electrical insulators)^ are generally referred to as "askarels" in the electrical industry. Mixtures of polychlorinated biphenyls are very resistant to degredation, are thermally stable, and resistant to oxidation, acids, bases, and other chemical agents. They are soluble in most of the common organic solvents and lipids, but only slightly soluble in water, glycerol, and glycols. PCBs are good electrical insulators. Although most individual polychlorinated biphenyls are' solids at room temperatures, the mixtures vary in consistency from mobile oils to viscous liquids or sticky resins. PCBs are generally prepared industrially by the chlorination of biphenyl with anhydrous chlorine in the presence of iron filings or a ferric chloride catalyst. Trace quantities of chlorinated naphthalenes and chlorinated dibenzofurans have been reported in some commercial samples of PCBs and it has been suggested that the presence of these impurities may be of toxicological significance.(1,2,3) Aroclor is a registered trademark of the Monsanto Company. b Inerteen is a registered Corporation for its brand of trademark of the Westinghouse Electric PCB containing dielectric fluids. c Kanechlor is a registered trademark of the Kanegafuchi Chemical Industry Company, Ltd. d, Pyranol is a registered trademark of the General Electric Company for its brand of PCB containing dielectric fluids. os'f1 I STLCOPCB4075281 -3- . Commercial PCBs are generally mixtures of many different chlorinated biphenyls* as shown in Table II, manufactured to meet operational specifications (such as dielectric constant, flash point, fire point, density, percent chlorine, and color); these commercial mixtures may vary chemically from batch to. batch. PCBs have found wide use in Industry and have been manufactured in the United States since 1929. The major domestic manufacturer, Monsanto Company, produces PCBs at Sauget, Illinois and reports manufacturing 40 million pounds of PCBs in the United States during 1974 (down from 85 million pounds in 1970).(4) Monsanto's domestic production and sales of PCBs by grade and category from 1957 through the first quarter of 1975 are shown in Table III. Uses PCBs ' are employed-in capacitors and transformers because they combine attractive dielectric properties with chemical stability and fire resistance. Approximately twice as many pounds of PCBs are used in the manufacture of capacitors as in the manufacture of transformers. Prior to the environmental concern surrounding the persistence and ubiquitousness of PCBs,(5) they were more widely used in industry as fluids for heat transfer systems, hydraulic systems, gas turbines, and vacuum pumps, as fire retardants, and as plasticizers in adhesives, textiles, surface coatings, sealants, printing, and carbonless copy paper. Beginning in 1971, Monsanto voluntarily restricted its domestic sales of PCBs to closed system dielectric applications in capacitors and transformers.(6) Other current domestic applications of PCBs Include use in investment casting processes, as heat exchange fluids, and as hydraulic DSW 323721 STLCOPCB4075282 .-4- fluids. Imports of PCBs have been estimated to exceed 375,000 pounds for 1974. Reclaimed PCBs also are reported to be available. (7) More than 95 percent of all power capacitors contain PCBs. Among their applications are use on electric utility lines, in air conditioners, and in the ballast of^fluorescent lamp fixtures. PCBs are employed for safety, reliability, and long life, as well as to achieve size compatibility with equipment and installation requirements. However, non- PCB power capacitors are being manufactured (e.g.. General Electric's Econol line and Sprague's Eccol line) which may serve as alternatives.(8) PCBs are employed in transformers at locations where their proximity to people and/or property demand a fire resistant dielectric. Approximately 5 percent of transformers are PCB filled and each of the transformers so filled contains between 40 and 500 gallons of PCBs (about 235 gallons is average). Possible alternatives to PCB filled transformers may include dry transformers (which are larger) as well as transformers filled with silicone fluids or other materials under evaluation.(8,9) Chlorinated terphenyls, as well as PCBs, are used in some formulations of wax for investment casting processes.(8) The chemical structure of chlorinated terphenyls resembles that of PCBs. Chlorinated terphenyls have been reported to have toxicological effects similar to those of PCBs.(10) Approximately 330,000 pounds of chlorinated terphenyls were imported into the United States during 1974(11) and 125,532 pounds during 1973.(12) Toxicity PCBs are poorly metabolized and tend to accumulate in animal tissues, including humans.(13,14,15,16,17) The accumulation, particularly in oS\N 323722 STLCOPCB4075283 -5- tissues and organs rich in lipids, appears to be higher in the case of penta and more highly chlorinated biphenyls.(18) Studies have revealed PCBs in human fat tissue and blood plasma. PCBs, in amounts greater than 2 parts per million, were reported in 198 of 637 (31 percent) samples of human fat tissue taken from the general population of 18 states and the District of Columbia.(14) PCB residues ranging up to 29 parts per billion have also been found in 43 percent of 616 plasma samples collected from volunteers in a southeastern U.S. county.(15) Human: The known toxic effects of PCBs in humans include an acnelike skin eruption (chloracne), pigmentation of the skin and nails, excessive eye discharge, swelling of eyelids, and distinctive hair follicles.(19) . For a number of years, chloracne of the face and neck has been . reported among workers exposed to chlorinated hydrocarbons. Workers exposed to PCBs in the process of insulating cables,(20) in the production of condensers(21) and in the manufacture of chlorobiphenyls(22) have reported these skin lesions along with systemic effects such as digestive disturbances, edema of the face and hands, burning of the eyes, impotence, and hematuria.(16,22) The toxic effects of PCBs in humans are further illustrated by a 1968 outbreak of poisoning in Japan that involved over 1,000 people who ingested PCB contaminated rice bran oil for a period of several months. The contamination of the oil (estimated 1,500 to 2,000 ppm) occurred when heat transfer pipes immersed in the oil during processing developed pin sized holes. The clinical aspects of the poisoning included chloracne, DSW 323723 STLCOPCB4075284 -6 brown pigmentation of the skin and nails, distinctive hair follicles, increased eye discharge, swelling of eyelids, transient visual disturbance, and systemic gastrointestinal symptoms with jaundice(19). In some patients, symptoms persisted 3 years after PCB exposure was discontinued. Infants born to poisoned mothers had decreased birth weights, and showed skin discoloration due to PCB placental passage. Two stillbirths to PCB exposed women were also reported.(23) Animal: The toxic effects of PCBs in animals have been studied extensively. Reports of malignant, non-malignant, and reproductive effects are shown in the following three tables: MALIGNANT PATHOLOGIC EFFECTS INDUCED BY PCBS IN ANIMALS PCB Mixture Treatment. Animal* * Effects Kanechlor 500(24) Kanechlor 400 Kanechlor 300 _ 500 ppm, 250 ppm and 100 ppm in diet for 32 weeks Mice Liver weight increased with percent chlorine and dosage. ` Kanechlor 400 and 500 produced liver cell hypertrophy. ' *' . . 500 ppm of Kanechlor 500 produced hyper plastic nodules in 7 of 12 mice and hepatocellular carcinomas in 5 of 12 mice Ho nodules or carcinomas in controls Aroclor 1254(25) . 300 ppm in diet Mice for 6 & 11 months Increased liver weight. Adenofibrosis in all mice fed for 11 months. None of 22 mice fed for 11 months had hepatomas. One of 24 mice fed for 6 months had a hepatoma. . Ho hepatomas in control mice. Aroclor 1260(26) 100 ppm in diet for 21 months Rats Hepatocellular alteration in 183 of 184 rats fed PCBs and in 28 of 173 control rats. Heoplastic nodules in 26 of 184 PCB fed rats and none in control rats. Hepatocellular carcinomas in 26 of 184 rats fed rCBs and in 1 of 173 control rats. DSW 323724 STLCOPCB4075285 -7- NON-MALIGNANT PATHOLOGIC EFFECTS INDUCED BY PCBS IN ANIMALS ` PCB Mixture Animal Route of Administration Effects ACUTE EFFECTS ' Unspecified Guinea Pigs Product Rats Containing Rabbits 42 Z Chlorine(27) Subcutaneous injection Skin application Feeding Fatty degeneration an atrophy of the liver. Aroclor 1242(28) Aroclor 1254 Guinea pigs Rats Mice Rabbits Cat Inhalation Aroclor 1242 produced no ill effects on basis of mortality, growth, pathology, organ enlargement, liver function, or hematological changes. Aroclor 1254 produced no harm ful effects regarding growth or mortality, but did produce ' ' enlarged livers with micro scopic evidence of hepatic . . cellular injury. Aroclor 1248(29) Monkeys .. . Feeding Weight loss, hair loss, mouth and eyelid edema, acneform lesions, decreased hemoglobin and hemato crit, severe gastric mucosal ulceration and extreme hypertrophy of the liver.' ' CHRONIC EFFECTS Aroclor 1254(30) Rats Aroclor 1260 Feeding Hypertrophy of the liver cells, a brown pigment in the Kupffer cells, lipid accumulation in the cytoplasm of hepatocytes and adenofibrosis. DSW 323725 ! STLCOPCB4075286  8- - REPRODUCTIVE EFFECTS OF PCBS IN ANIMALS PCB Mixture Animal Route of Administration Effects Aroclor 1242(31) Aroclor 1254 Aroclor 1260 Chickens Feeding Aroclor 1242 and 1254 reduced egg production and hatchability and caused thin eggshells. Aroclor 1260 produced no harmful effects. Aroclor 1254(32) Mallards Bobwhites Feeding No adverse effects. Aroclor 1254(33) Pheasant Feeding Reduced egg production and hatchability. Aroclor 1254(34) Mink Feeding Severely affected reproduction. Aroclor 1248(29) Female monkeys Feeding . Reduced ability to become pregnant. Pregnancies produced small infants with "PCBs in tissues. . % DSW 323726 '1 i STLCOPCB4075287 -9Occupational Exposure .It is estimated that 12,000; people are occupationally exposed to polychlorinated biphenyls. The majority of these exposures are in capacitor production and in investment casting processes. Permissible Occupational^Exposure The current Occupational Safety and Health Administration, Department of Labor standards for chlorinated biphenyls are 1 mg/cubic meter for 42 percent chlorine mixtures and .5 mg/cubic meter for 54 percent chlorine mixtures. These are based on the Threshold Limit Values (TLV) established by the American Conference of Governmental Industrial Hygienists.(35) % D5W 323727 STLCOPCB4075288 BIBLIOGRAPHY 1. Hutzinger, 0., Safe, S., and Zitko, V.: The Chemistry of PCB's, CRC Press, Cleveland, Ohio, p. 22, 1974 2. Bowes, G.W., Hulvihill, M.J., Simoneit, B.R.T., Burlingame, A.L., and Risebrough, R.W.: Identification of Chlorinated Dibenzofurans in American PolychloTinqted Biphenyls, Nature, 256:305, 1975 3. Curley, A., Burse, V.W., Jennings, R.W., Villanueva, E.C., and Kimbrough, R.D.: Evidence of Tetrachlorodibenzofuran (TCDF) in Aroclor 1254 and the Urine of Rats Following Dietary Exposure to Aroclor 1254, Bui Environ Contam and Toxicol, 14(2):153-58, 1975 4. Communication from Monsanto Industrial Chemicals Company, St. Louis, Missouri, September, 1975 5. Interagency Task Force on PCBs: PCBs and the Environment, COM-72 10419, Washington, DC, March 20, 1972 6. Polychlorinated Biphenyls: Monsanto Company's Program of Restricted Sales and Controlled Manufacturing Practices, Monsanto Industrial Chemicals Company, St. Louis, Missouri, October, 1974 7. Glenn Schweitzer, Office of Toxic Substances, U.S. Environmental Protection Agency, testimony at an August, 1975, Wisconsin hearing, quoted in Toxic Materials News, p. 139, September 15, 1975 8. Personal communications with representatives of the industry, October 1975 9. Dow Corning Dielectric Liquids for Power Transformers, Dow Corning Corporation, Midland, Michigan, received September, 1975 (booklet not dated) 10. Allen, J.R., Abrahamson, L.J., and Norback, D.H.: of Polychlorinated Biphenyls and Triphenyls on the Environmental Research, 6:344-54, 1973 Biological Effects Subhuman Primate, 11. Telephone conversation with a representative of the U.S. International Trade Commission, Washington, DC, September, 1975 12. U.S. Tarriff Commission: Imports of Benzoid Chemicals and Products, Washington, DC., p. 24, 1973 13. Biros, F.J., Walker, A.C., and Medbery, A.: Polychlorinated Biphenyls in Human Adipose Tissue, Bull Environ Contam and Toxicol, 5:317-23, 1970 14. Yobs, A.R.: Levels of Polychlorinated Biphenyls in Adipose Tissue of the General Population of the Nation, Environmental Health Perspective, 1:79-80, 1972 . c>s'N i I STLCOPCB4075289 . - L. 15. Finklea, J., Priester, L.E., Creason, J.P., Hauser, T'., Hinners, T., and Hammer, D.I.: Polychlorinated Biphenyl Residues in Human Plasma Expose a Major Urban Pollution Problem, AJPH, 62(5):645-51, 1972 . 16. Kimbrough, R.D.: The Toxicity of Polychlorinated Polycyclic Compounds and Related Chemicals, Critical Reviews Toxicology, CRC Press, Inc., 2(4):445-98, 1974 - 17. International Agency for Research on Cancer, IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man, 7:261-89, 1974 18. Hutzinger, 0., et al., op. cit., p. 2 19. Kuratsune, M., Yoshimura, T., Matsuzaka, J., and Yamasuchi, A.: Yusho, a Poisoning Caused by Rice Oil Contaminated with Polychlorinated Biphenyls, HSMHA Health Reports, 36:1083-91, 1971 20. Fulton, W.B. and Matthews, J.L.: A Preliminary Report of the Dermatological and Systemic Effects of Exposure to HexachloroNaphthalene and Chloro-Diphenyl, Bureau of Industrial Standards, Harrisburg, Pennsylvania, 1936 21. Mayers, M.R. and Silverberg, M.G.: Skin Conditions Resulting from Exposure to Certain Chlorinated Hydrocarbons, J Indust Hyg Toxicol, 20:244-58, 1938 . 22. Schwartz, L.: Dermatitis from Synthetic Resins and Waxes, Am J Pub Health, 26:586-92, 1936 23. Miller, R.W.: Cola-colored Babies, Chlorobiphenyl Poisoning in Japan, T.eratology, 4:211-12, 1971 24. Ito, N., Nagasaki, H., Arai, M., Masayuki, A., Makiura, S., Suginara, S., and Hirao, K.: Histopathologic Studies on Liver Tumorigenesis Induced in Mice by Technical Polychlorinated Biphenyls and Its Promoting Effect on Liver Tumors Induced by Benzene Hexachloride, JNCI, 51(5):1637-46, 1973 25. Kimbrough, R.D. ` and Linder, R.E.: Induction of Adenofibrosis and Hepatomas of the Liver in BALB/cJ Mice by Polychlorinated Biphenyls (Aroclor 1254), JNCI, 53(2):547-52, 1974 26. Kimbrough, R.D., Squire, R.A., Linder, R.E., Strandberg, J.D., Montali, R.J;, and Burse, V.W.: Induction of Liver Tumors in Rats by Polychlorinated Biphenyl Aroclor 1260, JNCI, (in press), December, 1975 27. Miller, J.U.: Pathologic Changes In Animals Exposed to a Commercial Chlorinated Diphenyl, Pub Health Reports, pp. 1085-93, August 18, 1944 OSW323729 r STLCOPCB4075290 28. Treon, J.F., Cleveland, F.P., Cappell, J.W., and Atchley, R.W.: Toxicity of the Vapors of Aroclor 1242 and Aroclor 1254, Am Ind 'Quart, 17:204-13, 1956 The Hyg 29. Allen, J.R.: Response of Primates to PCB Exposures, Federation Proceedings, 34:1675-79, 1975 30. Kimbrough, R.D., Lijider, R.E., and Gaines, T.B.: Changes in Liver of Rats Fed Polychlorinated Biphenyls, Health, 25:354-64, 1972 Morphological Arch Environ 31. Keplinger,M.L., Fancher, O.E., and Calandra, Studies with Polychlorinated Biphenyls, Toxicol 19:402, 1971 Appl J.C.:Toxicologic Pharmacol, 32. Heath, R.G., Spann, J.W., Kreitzer,' J.R., and Vance, C.: Effects of Polychlorinated Biphenyls on Birds, Proc 15th Intern Omithol Congr, Leiden, Holland, p. 476, 1972 33. Dahlgren, R.B., Linder, R.L., and Carlson, C.W.: Biphenyls: Their Effects on Penned Pheasants, Perspect, 1:89, 1972 Polychlorinated Environ Health 34. Ringer, R.K., Aulerich, R.J., and Zabik, M.: Effect of Dietary Polychlorinated Biphenyls on Growth and Reproduction of Mink, ACS Div Water Air and Waste Chemistry, Preprints of Papers 12:149, 1972 35. Federal Register, Vol. 37, No. 202, p. 22140, Wednesday, October 18, 1972 % 1r STLCOPCB4075291 TABLE I TRADENAMES FOR KNOWN PCB CONTAINING PRODUCTS Tradename Aroclor Chlorextol Clophen Dykanol Fenclor Inerteen Kanechlor Noflamol Phenoclor Pyralene Pyranol Santotherm Therminol* Tradename Owner ^ Monsanto Company St. Louis, MO Allis-Chalmers Milwaukee, WI Farbenfabricken Bayer GmbH Germany Federal Pacific Electric Co. Newark, NJ Caffaro S.P.A. Italy Westinghouse Electric Corp. Pittsburgh, PA Kanegafuchi Chemical Industry Co., Ltd. , Japan Wagner Electric Corporation Newark, NJ Prodelec France Prodelec France General Electric Co. Schenectady, NY Mitsubishi-Monsanto Japan Monsanto Co. St. Louis, MO *Therminol products now formulated in the U.S. do not contain PCBs. I * ' DSW 323731 rf STLCOPCB4075292 P e rce n t. Source o f component com positions; H u tzin g e r, 0 . , e t a l. , op. c i t . , p . 23 P e rce n t. Source o f component com positions: T h ru s to n , A ,, PCB N e w s le tte r, No. 3 , J u ly 1971, q u o te d in ' I t o , N ., e t a l. , op. c i t . , p . 1637 l o cr 01%. p . 23 M onsanto com positions:- component of Source . 0 , . thcaint . ss op le , . al ted et te ., de 0 , None nger i z t t. u en H erc in p d t te h o g u ei q W eight-w Company, c zv 6s >H *< <I P to 0 rt x cr tPo n 0 mo 0 OOMO 0 0p. p p od 0 to 0 0B* Pto O 0 CO p 00PQ 00PQ PM NPO. P tP0o . On *ao 0P OO) ft 0 oto (0 P 0O 0P S OP* P 0pCL 0 pCL Pa p 0 oHi CL 0P0CL P3P0 0 ofh cr p fnt Ho 0x Ort 3Prt 0p P fot Oo 0 *oa0 CO 0Or0t** P CO 0p S? Oc3PPfCOQhr ocpr fMBt P o30: CpO p oo *ap00 & 0Cl p C(0 ow0 ft v0; d0* X ooB rC0t P0 P Pto *< CPPL ft 0Prt *PM0 OMC P 0 0o0 & o 3? 3Pocr mo oort POopM 0o0H-* 0O 0M* *0 0P ` *P< c0r v8; *tp0t ft PO 0HO 0o0 Vp0J P ts R O 0M o 0o0* HO- 0 Po Of0MO0t* *H0- p p 0P P HPrt *0PfMOfO0H00tt* 0P VP- nHoMfO00Ot* M *c0r pp HOCJ* O00MOf0t* 0P XP OP0 oM0o oft o 0H0* v0PPj *0 0to vP- *Otoopapp00o a ooP *a mo 0p fX*. 0BP o O0M 0HPP 21% 11 51 32 none dete 0o0CPPL PPPO PCL o0PCL CL p oP00CPpL POP oA to Cn CPL PO 0P PP o0 p CL oCt0poL poPp 0P CL OA 01 to O*s| OA CP0PoL POPP C0pL . 0tPaCoL PoPP PCL 0to1 \> f-* OA 0 IO P CO OA oA f- 0 CO CO HItOo-* >0oo j PMO 0 to fO0---p >ofOOMt 0 to X fto >0 top ooo0M tCowpO M5xPl MOH in -O I tLt~on* p >0onM o onj tw~* * OtrPi W MM o ft0o-o0 >oMOfo( H tcoo oo> to H Oo Po 0 oft pCO in in tsoi HCO OOO-PPrP> 0MO ft CCOn COoA WPp H O fpt O0M ft DSW 323732 STLCOPCB4075293 X t> > > > > > >> a SX * ; H *i ri i i *-( o rt rt O rt a txj rt M 03 M P v: o rtO o O o O O o o o > rt > (U 01 CO r* o- 01 p o c: y o CO S CO C! c3 O o o o r> O o o o 3 p. M rt CD 0> o C M rt M CO CO if fl> pP M M M M M M J-* M M CO p O rt rt o CO cr oi CO tn OoOooOoOO H H* (-4 H* t-h t-( c rt H rt rt rt i n r< i *i n r( -! M rt ro H O rt O M h rt i Hi X M rt o H- e o H- O Q 3 O H* 03 o Pi o o p O KM H* H* H H-* H* -* -- --* M (--4 < S a) N n B CL 0) O C3 3a O ro ro ro ro to ro ro ro CO IS rt (P c; 3 XO CO to rt to a H-* ON ON ON Ln 4> P- to ro > CO H* -t tn rt ^ t-h > rt > o ON 00 to o 4> 00 ro to H-* P O rt Vi (0 f rt rt tn ii i CO w M H H- CO (0 H to > to O H- H* M I-1 rt Oi rt a rt w rt v: Vi -<i Hi CO H* H PP rt O HP P Pi PP CO o Hi H* o rt Ho 3H (f CO H CO - to Ln 4 Ln f-- H tn 00 4 Ln tn to VO tn to to ON to ON o ON 00 I--* 4 Ln to 4 o to tn 4 Ln VO to 4 00 O O tn Ln CO ON 4 to I-- tn to o 4> 00 tn tn Ln 4 ON CD Pi ort o i rt o .> rt H to W o Ln ON 1 H to CD H-* i-- o 4> H-4 o -- 1 ON vl On 00 On to rt ro o VO VO 4> Ln 4>* -- to Hi 0J VO 00 ON ON VO *-- ON 4> ON o Ln --1 to 1 to CD CD I--4 -P' I--* 1 CD VO to *^1 CD OO 1--1 *vj Ln ON 4> O VO 00 ON Ln On ON VO Ln oo O 00 Ln to 00 40 f--4 VO ON ON 4> ON On 4>- to to 00 > On 4 o 4N CD 4> H-* VO O Ln to o 4 o 4 ON 4>* Ln Ln to 4S Ln OO 4> 4>* to 4 to CD 00 00 --* 00 ro Ln VO VO Ln VO to o o o to f-* -p> to o ON 4> 4> VO Ln Ln to 4 4> 00 ON 4> to Ln o t--* to to Ln VO 4 O o o to VO to O H-* to H 4N I--4 to 4> 00 --1 to O oo 4> O Ln to 4> to to VO ro 4 00 ON o o to o -- to 00 o ON to to I-4 4^ 1--* to to 4 On to VO --4 to to to On --4 00 4 t-- 4> o H* tn h-4 40 I--1 --* tn to O to VO W 4> 00 Nj I--* O O VO O to 4 moouiUim&ooh --1 to t--* 1 CO VO >--4 *-- 4> to 1 CO 'O o ON to ON o ^4 to -P> ON -- CO I--* ON CO to H to H-* 1 1 4^ vo --4 --* Ln to 4^ Ln Ln to -4 Ln O Ln CD CO ON to 4> O Ln to Ln vo -* to t--4 ON Ln to i-- 00 to 4V 4> O H-* O O o l*J ON to o *4 to Ln VO O to Ln VO VO O H to 1--* 1 vo ON to I--* to 1 Ln *4 oo ON 4>* VO to O to to O Ln *vj 00 00 -4 to 00 I--4 to 4> --* I--* --4 to 1 to i--4 h- i--4 Ln O 1 tn 4^ to Ln tn ON VO I--* 4^ tn to O oo to Ln ON 4 Ln Ln ON O O to On . oo to Ln --* t-4 -p** to VO to ON o ON 4> ON VO o a t-* ON 00 rt Pi t--4 Ln to to i--4 00 to r-* Ln t-* ON 4>- --* VO ON 00 --k Oo w rpt* O f-- CO Mti O e o' a *-- ON -4 O *>4 ON Cfl Cn CO P rt P rt rt r>t ON H-* to to VO 00 VO ON acn rt rt m > ort r6*1 4>* 4> VO vo o O ci f art w Hi o o w M Pi rt M t--* *4 oo Pi W M to to Ln I--4 o h- s ON O O VO C CO M Ln ON Ln r--* --4 4^ *4 O P p ~-j Ui n > cn 'C--O " Ct-O1 to to W o to 4>* 4^ I--4 p to vo vo o VO 4 r- 4> M V to to on ON 00 LO 4> ON 00 o o 00 oo o -- VO 4 ro to to 4 On tn NO to to 4 o t- o O O On O o o Ln tvoi to 4>* oo 4 to Vi to NJ H VO 4* 4^ 4> 4 4 to . On to CO to to *- On ON vo H ro Ln 00 o Ln Ln o O O Ln o 4 O 4 - to 4> 4n O ON tO 4> tn 4> O to 4> 4> VO O ON Ln on On I--4 VO 4 4N to to ro ON *-* tO On >-- O -- OOOOtAO*--*03 * * ** * * on 4 I-4 4 00 h-4 rt VO Ln vo Ln vO 00 tO OO LO 4 X> ON 00 ON to Ln C (13 i rt (0 i DSW 323733 I t i STLCOPCB4075294 SOURCE: M o n sa n to I n d u s t r ia l C h e m ic a ls Com pany, S t. L o u is , M is s o u r i, S e p te m b e r, 1975 to w a rt H c/> O P* P Mo X rt XI H* OO H0 rt Hi CO rt 0 CO MP 0CO CD CO Hi H- CD 00 0 p P-. H 0CO rrtt1 CD p CO rt 0' rt <O 0 rt H* N M CD 0H O' M> 0 X> XJ rta* rt* p HO H- CD 0 rt 00 rt O Vi 0 (0 CO 0 Hi rt H* 00 0p o- H H CD O CO 0 rt P CD 0 CU CD < P rt M CD P4 rt* CD a p tl rt 0 00 X CD 0 i-C rt 0 Ort O CD rr > p. * > > > >- > > > > > M O H O H o H O o o O H O H O O O rt* o rt* O rt* o rt* o rt* o rt* Ort O rt o o rx w C/) d rt o rt *-* rt rt <0 M 0 p 0 rt 0 XI 0 CO a. 0 H CO 0 0 o H rt O rt o CO 0 0 o o F) wi c : C D rt VO P3 rt to CD OOOOoOO oO r| H H H H H H I--* H-* i--*1 rt rt I-- --* rt O l--* to o\ N> ON to ON Cron to 4> to 4> to o to to O' 00 to o 4> 00 to to rt HM n ca > f w oo tt> M (T> HO* rt Hi O Ih---*1 P rt MH c 0 H' O N(t> H >H 30 H 0 0 0 O H 0 O0 CO CO Hi a. p. H* X>I PCO rt 0 &H rt XI MH H- M < 0P rt O MH O )I M X rt rMt O rt rt o O rt CO rt CD rt > rt > o fpi CO rt rt CD M M > to o w rt M sz; CO rc O u0 CPO 0 0 o - o rt rt rt tri H H CO 5 O H* n O W1 0CO 0 M o o s 1 1 sj 4> rt rt 00 Cn 4> to !-- CO 00 ON 'O to VO to rt o rt VO to ON Co rt 1 Cn ON to o 1 rt VO ON Cn 4>* H 00 00 VO Cn 4> rt 1--* ro 4> to rt vO 4> CO ON *--* 1 ON On CO CO 1 f-- CO ON CO Cn to ro o Cn rt Cn CD VO 4> Cn tO VO VO 4S 4> 00 O 4> rt 1 ON to 00 1 -- Co CO o 00 t-- rt rt 00 to o CO to vo Cn o VO ON o 00 -o ON Cn CO H 1 ON ON 4N vo 1 1--* CO tn to O 00 to Cn ON 4> VO to to 4>* VO CD rt o 4^ CO H 4> * to 1 ON ON CO o rt1 to 4> Cn CO -P" ON to CO VO to ON Cn to 4N O to Cn Cn Co 4> 4> O H I vj Cn cn 00 1 to 4^ ON VO O Cn CO rtCD rt ro rt rt --* ON 4>* 4S ON CO o CO h- ro 1 00 ON Cn CO rt1 4> Cn to to Cn Cn rtVO 4> CO CD CO 'O vo rto ON Cn o 00 CO ON H I--* I /^N to H-* 1 I 1--* O VO -O ON 1 V--' to Cn o I--* CD Cn 4> to h-* I CO 4^ Cn 1--* | i vo O 'O Cn 1 Co VO -- Cn -P" VO VO vo Cn vo -- I 4> On Cn H* to 1 I Cn 4>* vD Cn ON 1 VO CD ON 00 CO vo 4> vo Cn fr--4 I ON ON 'O K-- to 1 I to VO VO Cn Cn t 4>* ON to Cn to 4>* h-* vo o t--* I VO Cn ON to -p> 1 I o vo to M --* 1 VO CO 00 t--* H-* CD Cn 1-- 4S o K- I OC Cn i-- CJ l VO CO vo ON vo I--* to CD 00 00 -- Cn 4> to 4^ I--* Cn 'O H l VO Cn HO l -- ON to Cn VO Cn CD O vo to 4> 00 --* On o 00 Cn to H t--* 1 o VO -- 4^ 1 CO Cn VO ON O vo CO -P- vo VO 'O to O to 4> VO . to to /--"N to to h- vo v--' vo --1 vo tn 'O to /*N ON to o h-4 V/ ON ' I--* t-- *^> Cn CD o a CO > to /~N 1-- y-N to to -- H-1 o *-- vo Cn vo rt oO td rt P4 ;--1 M s: --> o vO u p CD Cn CI| CO r~\ rt > rt rt rt 0 i-3 PI M 0 rt & > M D- td i--l n M to CO CD rt > H Cn 'O H* o t-1 a to to VO VO o rt O *-- 1-- ON Hi o o H o` 4* vo to CO 'O ON to Cn Cn to *-- 00 tn o rt a 0 rt PI rt o i--* K H* p VO M 0 0 ON O P h~* PCD 4> >F* CO > 0 &. vo v CO f v--/ ON W 1-- o CO o to to 00 00 to o to V-/ 4> Cn to to I--* VO ON to to 4n to 00 4n ON t-- 'O CO CO ->o to 4> --1 o ON CO 4> tn 4s 4> O O OO 00 VO ON CO ON vo CO M VO ON 4N STLCOPCB4075295