Document 94aZM5b80QVoZaxYR4GzNbbe

Monsanto U afrom (name location) Dept, of Medicine & Environmental Health } B. W. Eley DATE: SUBJECT: REFERENCE: November 10, 1975 (Update 2/24/76) CC: Jack T. Garrett Summary of PCB Air Monitoring WGK and Newport Plants TO File (Aroclors) This memo summarizes the recent industrial hygiene activities in the Aroclor departments at the W. G. Krummrlch and Newport, South Wales plants. Described are air monitoring procedures, analytical technique, and resulting atmospheric levels of polychlorobiphenyls to which workers are exposed. A short discussion of analyzing PCB's in body fluids is also included. W. G. KRUMMRICH SAMPLING PROGRAM: - The first series of PCB air samples were collected on August 21, 1974 by Harvey Zar, a summer student working in the En vironmental Control Group at the WGK Plant. The air samples were collected in 6" x 0.093" I.D. resin tubes filled with "Tenax" gas chromatographic packing material which has since been used for sampling and analyzing high boiling compounds in the vapor state. The vacuum source used consisted of an empty 11-Liter Freon-12 cylinder which was evacuated to 30" (Hg) in the laboratory prior to sampling. A vacuum gauge and needle valve were installed on the cylinder in order that the sample volume (as related to differential pressure) could be calculated. In the field the U-type resin tubes are connected to the vacuum source and the needle sample is then opened to collect the sample. Sample volumes ranged from 2-5 liters of air in this study. The used resin tubes were analyzed by Jim Francis in the WGK Laboratory using a Varian Gas Chromatograph with a FID (flame ionization detector) unit. The sample tubes are connected in line with a 24" x 0.092" I.D. separation column packed with 60 - 80 mesh Tenax resin. After thermally desorbing the vapors entrained within the sample tube, carrier gas sweeps them into the GC column for separation and further quantitative analysis by the FID unit. This analytical technique is sensitive down to 0.5 micrograms of polychlorobiphenyls. Therefore, given a in-iom 12/75 DSW 282957 STLCOPCB4064286 Page 2 5 liter sample volume, the lower limit of PCB detective would approximate 0.1 mg/M-5 in air. The resulting atmospheric levels of Aroclor 1242 were detected during the August, 1974 study. Sampling Location (Dept. 246) mg/M^ Aroclor 1242 1) 2nd level near chlorinators 2) Ground level by fume scrubber 3) 2nd level by South walkway 4) Ground level under chlorinators 0.37 0.42 0.50 O.56 These levels are below the current TLV of 1.0 mg/M^ for the lower chlorinated material but do borderline or exceed the "action level" at two locations. A more recent sampling program completed in October, 1975 utilized a different collection procedure and more sensitive analytical technique. A group of six (6) air samples were ~ taken using two midget impingers containing 10 mL. of toluene each as the collection media. The impingers were connected in series to an electric bellows type pump operating at a flow rate of 5^5-580 mL/minute. Collection periods ranged from 3 4 hours per sample. During the actual sampling, the impingers were immersed in an ice batch to lessen the loss of solvent through volatilization. After absorbing the PCB's in the impingers the toluene was evaporated in the laboratory to milliliter amounts for analy sis of solubilized PCB. The analytical technique consisted of the injection of a ju-liter quantity of toluene into a gas chro matograph, separation of the sample components on a. GC column, and final detection of the PCB's using a high temperature Ni3 electron capture cell. A more detailed description of the exact procedure used along with temperature and column condi tions is available from J. H. Francis in the WGK Analytical Group. The following results were obtained from the October sampling program. Date Location Concentration mg/M^ Aroclor 1242 10-9-75 10-9-75 2nd level near batch chlorinators 0.022 2nd level (continuous chlorinators) 0.012 continued.. DSW 282958 STLCOPCB4064287 Date Location Page 3 Concentration mg/M^ Aroclor 1242 10-13-75 2nd level (near batch chlorinators) 10-13-75 2nd level (continuous chlorinators) 10-14-75 Directly above a sever sampler on the east side of department 10-14-75 Ground floor at scrubber discharge 0.057 0.058 0.006 O.338 As shown all exposure level are well below the current TLV of 1.0 mg/M^. It is of interest to note that the detection sen sitivity using electron capture is in the nanogram range or about l/1000th of the FID sensitivity. The exposure levels as determined by the October, 1975 study were much lower than those detected in the Aroclor Department last year. These differences could be accounted for by the general upgrading of working conditions that has been instituted within the department over the past year and by the use of a more sensitive analytical approach. I expect the latter cause to be the more significant. NEWPORT SAMPLING PROGRAM: ~ During the periods October-November, 1974 and July-August, 1975 the Technical Services Departmental staff of the Newport, Wales plant collected air samples in the Aroclor Department and analyzed the PCB content by electron capture gas chroma tography. The attached Progress Report provides detailed methodology used and results obtained. The exposure levels at Newport compare favorably with those reported at Krummrich during October, 1975* BIOLOGICAL MONITORING; In talking with Scott Tucker, Jim Mieure, and Bob Kaley in the MICC Applied Sciences Group, they indicated that some work had been done several years ago at WGK in analyzing PCB's in blood. The PCB in blood samples were extracted with hexane followed by a gas chromatography-electron capture detection analysis simi lar to that used in analyzing air samples. I do not know what PCB levels were obtained from that study but I was told that Dr. Kelly received a copy of the results. Evidently this in formation should be available somewhere in our medical files. Jim Mieure stated that Monsanto has to date done no PCB analy tical work with urine. However, based on a study in the DSW 282959 STLCOPCB4064288 Page 4 literature in which PCB content in rat urine had been deter mined, he felt we did presently have the capability of analyz ing PCB in urine down to a sensitivity of 1-10 ppb. The tech nique wjould be similar to that used for blood. I think Jim would be interested in pursuing the methods development if Medical considered it worthwhile. Bruce W. Eley Addendum: On January 22, 1976, two general area samples were collected by WGK in the Aroclors Depart ment. The material, polychlorinated biphenyl, was collected in irapingers containing toluene. The results follow. Location PCB(mg/M3), in Air At batch chlorinators on 2nd level At continuous chlorinators on 2nd level 0.18 0.08 - The current TLV for chlorodiphenyl (42# CL2) is 1.0 mg/M . The results shown concentrations well below the estab lished limit. DSW 282960 STLCOPCB4064289