Document G5onDyQ4NeODGrV3GV99rDN3r

DEPARTMENT OF HEALTH. EDUCATION, AND WELFARE PUBLIC HEALTH SERVICE FOOO AND DRUG ADM INISTRATION W A S H IN G T O N . D C 20204 December 23, 1974 Dr . Janies Mieure Monsanto Company BOO North Lindbergh St. Louis, Missouri 63166 Dear Dr. tfieure: aIn response to your recent request made to John Roach, I am enclosing copy of the presentation made at the October 1974 AOAC Meeting, entitled "Finding of Chlorinated Dibenzofurans in Aroclor PCB*s of Recent M a n u f a c t u r e A d d i t i o n a l work to determine the levels of chlorinated dibenzofurans in the Aroclors is now underway in our laboratory. You are probably aware that evidence for chlorinated dibenzofuran contaminants has been reported for PCB's made in France and Germany, by Vos, and in Japan, by Roach and Pomerantz, prior to our recent, findings in the 1200 Series Aroclors. You may have considered, as we have, possible means by which the chlorinated dibenzofurans are formed. Can you please tell us whether the parent dibenzofuran has been looked for or found in the starting biphenyl? Are hydroxylated, chlorinated biphenyls, conceivable precursors to the dibenzofurans, present in the Aroclors? Are they formed in a base treatment step (lime or alkali) after chlorination? Perhaps there are alternative explanations for which you have some experimental support. Your discussion of these points would be welcome and I look forward to your response Sincerely, Enclosure C. F .-'Jelinek, Ph.D. Director Division of Chemical Technology (UFF-420) Bureau of Foods NEV 01^738 PLAINTIFF'S EXHIBIT 713990 AoflC Prtsevi-oi- Och 197Y X ? 0 c l \ o k JI X . Por*eran1-z FO A Polychlorinated biphenyl mixtures have previously been used as additives to improve the chemical and physical resistance of plastics and surface coatings and have been used in electrical equipment and as hydraulic and heat transfer fluids. Polychlorinated biphenyls are now wide spread in our environment. The presence of contaminants in commercial chlorinated biphenyl preparations which are potentially more toxic than chlorinated biphenyls is therefore of considerable concern. Vc reported at last year's AOAC meeting the presence of chlorinated x dibenzofurans in Kancchlor 400, a commercial chlorinated biphenyl h mixture of Japanese origin. This finding raised the question of whether chlorinated dibenzofurans in Kanechlor 400 may have contrib C*. I Ci- u t e Lu the vuserved toxic effete* mica ^jbW vl* >iL i s 0 Kanechlor 400 was ingested by several hundred Japanese in the Yusho incident as reported by Kuratsune. Chlorinated dibenzofurans were </ P reported ly Vos and co-workers in two commercial chlorinated biphenyl mixtures of European origin that had shown high mortality, liver necrosis jnd chick edema-like lesions in chicks. Vos failed to detect chlorinated dibenzofurans in Aroclor 1260. In this paper, we report the finding of chlorinated dibenzofurans in % production lots of Aroclor 1254, 1242 and 1016 that were manufactured in 1973* No evidence was obtained for chlorinated dibenzofurans in a production lot of Aroclor 1221 manufactured during the same period. , NfcV 0 1 A 7 3 9 713991 -2- Tlie procedure used in the current work was a considerably modified version of that applied earlier to the analysis of Kanechlor 400, The current procedure used three types of adsorbent columns for sample preparation. Call for Slide 1, (Flow chart of sample preparation) The alumina column was 50 g of WOELM W-200 alumina which was eluted with 400 ml of 1% methylene chloride/hexane followed by 400 ml of 20% methylene chloride/ hexane. The 20% eluate containing the material of interest was then concentrated to less than one ml prior to addition to an alumina micro column. The micro columns were disposable pipets of roughly 5 mm bore into which a small wad of glass wool had been inserted to retain the aluminum oxide. WOELM W-20'l alumina was poured into the columns to a depth of 2.5 cm. The micro colutns were eluted with 10 ml of 1% methylene chloride/hexane and 6 ml of 20% methylene chloride/hexane. Prior to the Florisil column, cluates from two, 100 mg Aroclor portions, each being less than one ml, were combined. The Florisil column was 8 g of 60/100 mesh PR grade Florisil which was eluted with 150 ml of hexane and 100 ml of 5% ethyl ether/hexane. The latter eluate was concentrated to less than 20 microliters and was never permitted to go to dryness. NEV 014740 713992 -3- A 11 for Slide 1. The concentrated eluates were analyzed by combined gas chromatography/mass spectrometry using a Flnnigan 1015 quadrupole mass spectrometer interfaced thru a Gohlke all-glass jet separator to a six-foot by two millimeter bore 3% OV-101 column at 200C with a helium carrier gas flow of twenty milliliters per minute. Mass spectra of authentic chlorinated dibenzofurans were obtained under identical operating conditions using a mixture of mono-, di-, tri-, and tetra- chlorodibenzofurans kindly provided by Dr, Albert Pohland of FDA. A summary of the results for each Aroclor sample analyzed is given in the following slides. In each case, the mass spectral data obtained for the chlorinated dibenzo furans included the parent ion and fragment ions derived from losses of CO + Cl. Taken together, these data are considered characteristic for the chlorinated dibenzofurans. Each analyzed extract also gave evidence of some chlorinated biphenyls indicating the column separation procedure used <fid not completely separate Cl-DBF from the chlorinated biphenyls. NEV 014741 713993 -4In each Aroclor found to contain Cl-DBF, the level of contamination was estimated to be in the ppm range. Studies are now under way to obtain more meaningful quantitative data on the level of Cl-DBF contamination. Call for Slide 2 . along Six, 200 rag replicates of an Aroclor 1254 sample were analyzed^with a reagent blank. Tetra- and pentachlorodibcnzofurans were found in all six extracts. Hexa- and heptachlornaphthalene were also found. None of these compounds was found in a reagent blank equivalent in size to a 200 mg sample. Coll for Slide 3. TVv% f%nn fno repUrflt-pc pti Arnr.lor I7lx'A ppmnie were analvzeu. Ul * ui.1 anvl tetrachlorodibcnzofurans were detected in both. In addition, tetra-, penta- and hexachloronaphthalene, a trichloroterphenyl, and three unidentified halogenated compounds were ietected. The unidentified halogensted compounds may form a homologous series differing from one another only in their degree of chlorination. The tentative molecular weights of these unidentified components were 278 (possible 4 chlorines), 312 (5 chlorines) and 346 (possible 6 chlorines). These may have been inethylchloronaphthalenes or chlorophenyl cyclopentadienes. However, their only observed fragmentation was a loss of one chlorine atom. The data for these unidentified compounds was therefore too sparse to permit identification. NEV 01^7^2 713994 5- Coll for Slide 4 . ivo, 200 mg replicates of an Aroclor 1016 sample were analyzed. Dichlorodibenzofuran was found In each of the samples. Call for Slide 5 Initially, 2, 200 mg replicates of an Aroclor 1221 sample and a reagent bln were analyzed. No Cl-DBF were detected. Sensitivity of the instrument for the molecular ions of lower Cl-DBF was then enhanced by limiting the mass scan to roughly 170 to 290 a.m.u. and a third 200 mg sample was analysed. The results were again negative for Cl-DBF. Mono-, di- and tiichlorobiphenyls were the only halogenated species detected in the sample extracts. The reagent blank analyzed with this lot contained a barely detectable trace of dichlorobiphenyl. Another reagent blank was then prepared and was found to be free of halogenated materials.. Call for Slide 6. (flow chart of recycle experiment) * To investigate the possibility that the observed chlorinated dibenze- furons may be artifacts produced in the sample analytical NEV 014743 713995 ? i * %I \ 1i ; i i 1 1; -6- procedure, duplicate experiments with Aroclor 125A were carried out in whirl. all eluates normally discarded in the procedure were retained and pooled. The pooled sample eluates were then concentrated and rcsubjccted to the sample preparation procedure. The original samples and the samples prepared from the pooled eluates were examined by combined gas chromatography/mass spectrometry on the same day under identical operating conditions. No chlorinated dibenzofurans were * detected in the samples resulting from the pooled eluates that had been resubjected to the sample preparation procedure. If we had found a significant level of chlorinated dibenzofurans in the pooled samples, this would have suggested that the procedure it self was capable of making chlorinated dibenzofurans from one or more ronsti tupnfc t-hp cot^rOp In summary, we have shown the presence of chlorinated dibenzofurans as trace contaminants in recent production lots of Aroclor 1254, 1242. and 1016 but not in Aroclor 1221 when samples of comparable size were analyzed. No dibenzofurans were detected in reagent and equipment blanks run with the samples. The procedure itself does not appear to produce chlorinated dibenzofurans as an artifact of analysis. The authors wish to acknowledge the technical assistance of Tom Lyon and Linda Laderach in the preparation o these samples for analysis. * 713996 10 0 MG AROCLOR 50 G ALUMINA COLUMN 1 0 0 MG AROCLOR IN P A R A LLE L PREPARATION 20% METHYLENE CH LO RID E IN HEXANE 2 ALUMINA MICRO COLUMNS | 1 2W, METHYLENE CHLORIDE IN HEXANE s_____________________ _______________________ COMBINE E X TR A C TS FROM 2 0 0 MG AROCLOR 8 G F L O R I S I L COLUMN 5% E T H Y L ETHER IN HEXANE g c /ms NEV 0147^5 713997 i V AROCLQR Y?3\ p r t u c t i o n d a t e 10/73 SAMPLES ANALYZED: 6 SAMPLE SIZE: 200 MG FOUND: TE7RA- AND PEN r/XHLORQDIBENZOFURANS CH.ORINATED NM ITHALENES 713998 TTTT" T*' AROCLQR1242 9/73f r d u c t i o n d a t e 2SAMPLES ANALYZED: 6CCSAMPLE SIZE: MG FOUND: D I - , 7 R I -, AID TE7RACHLORODIBENZOFURAiNS CHLORINATED FA W HALENES TRICHLCROTERPH ENYL UNIDENTIFIED HALOGENATED COMPOUNDS 713999 NEV ul<7<*7 * ARQCLOR1016 10/73prccxtio n date sam ples an alyzed: 2 200SAMPLE SIZE: M3 found: DICHLORODIBENZLFJRAN 714000 NfcV O I W ' H ) ARDCLOR 1221 6/75pr o d uctio n d a t e sam ples an alyzed : 3 SAMPLE SIZE: 2C0 MG No CHLORINATED DIBENZC/URANS DETECTED NEV 014749 ORIGINAL SAMPLE NEV Q14750 > 714002