Document NE4DraVbdxGzZn9gd0KJg0xDE

July 30, 1985 MIDWEST RESEARCH iNSTTTUT 425 Volk*r Boul4vr Kansas C*ty, Mssou 64U TflJap^onfl fflISI 753-76C AUG 2 }$% Dr. John H. Craddock Prod. & Envn. Safety Director Monsanto Company 800 North Lindbergh Boulevard St, Louis, MO 63167 Dear Dr, Craddock; Enclosed is a copy of our report, ''Products of Thermal Degradation of Di electric Fluids," Because of your similar interest in this field, I thought you might find these results interesting. We are continuing our research in this area and would appreciate any suggestions you have regarding further work. Additional copies will he available from NTIS. Sincerely, Mitchell D. Erickson Principal Chemist MDE/gls Enclosure cc: Daniel T. Heggem Work Assignment Manager HONS 213620 c/EPA ijrvtoiJ Stem's Er.yironrne^lal Pr 0*<?C Non ^rjC'CV ON ce Of Toic Substances WashinQlon DC DA SeO/S 05-C^ May '90$ Products of Thermal Degradation of Dielectric Fluids MONS 213621 PRODUCTS OF THERMAL DEGRADATION OF OIELECTRIC FLUIOS By Stephen E. Swanson Mitchell 0. Erickson Leslie Moody WORK ASSIGNMENT NO. 23 INTERIM REPORT NO, 2 EPA Contract No, 68-02-3938 MRI Project No. 8201-A{23) May 23, 1985 For U.S. Environmental Protection Agency Office of Toxic Substances Field Studies Branch, TS 798 401 M Street, S.W. Washington, DC 20460 Attn: Joseph J. Breen, Project Officer Oaniel T, Heggem, Work Assignment Manager MONS 213622 01SCLAIMER This document has been reviewed and approved for publication by the Office of Toxic Substances, Office of Pesticides and Toxic Substances, U.S. Environmental Protection Agency. The use of trade names or commercial products does not constitute Agency endorsement or recommendation for use. MQNS 213623 PREFACE This report presents the results of a portion of Work Assignment No. 23 on U.S. Environmental Protection Agency Contract No. 68-02-3938, "In cineration Testing of PCBs." The work was done at Midwest Research Institute CMR10 during the period September 28, 1984, to January 28, 1985. This work was performed as a follow-up to work presented previously in "Thermal Degrada tion Products From Dielectric Fluids," by Mitchell D. Erickson, Christopher J. Cole, Jairus D. Flora, Jr., Paul G. Gorman, Clarence L. Haile, Gary D. Hinshaw, Fred C. Hopkins, and Stephen E. Swanson, Interim Report No. 1 on this work assignment, November 19, 1984 (Report No. EPA-560/5-84-009). Mitchell D. Erickson was the MRl Work Assignment Leader. This report was prepared by Dr. Erickson, Stephen E. Swanson and Leslie Moody. The thermal combustion system was operated by Gary D. Hinshaw, Christopher J, Cole, Paul G. Gorman, and Fred C. Hopkins. Laboratory work was done by Mr. Swanson and Ms. Moody. The GC/MS data were acquired by John Gamble, Jon Onstot, Gil Radolovich, and Margaret Wickham, Mass spectral data were interpreted by Dr. Erickson, Mr. Swanson and Ms. Moody. The EPA Work Assignment Manager, Oaniel T. Heggem of Field Studies Branch, provided helpful guidance and advice. MIDWESJ RESEARCH INSTITUTE Approved: Clarence L. Haile Oerwty Program Manager WV 0 yohn E. Going Program Manager James L. Spigarelli, Director Chemical and Biological Sciences Department 11 MQNS 213624 I. II. III. IV. V. TABLE OF CONTENTS Introduction................................................................................................. Summary.......................................................................................................... Experimental Methods................................................................................ A. Thermal Combustion System................................................... 8. Chemical Analysis.................................................................... C. Selection of Compounds forEvaluation............................. Results and Discussion............................................................................ A. Continuous Monitoring Results.......................................... B. PCB-Containing Matrices....................................................... C. Non-PCB Dielectric Fluids.. . .......................................... D. Quality Assurance andQuality Control............................ References...................................................................................................... Page 1 1 2 2 4 4 6 6 6 12 20 24 i i i MONS 213625 Number 1 2 3 4 5 6 7 8 9 10 LIST OF FIGURES Title Page Summary of conversion efficiencies {%) for total PCDFs from Phase III and Phase IV runs..................... ............................. 3 PCDF formation in PCB-spiked mineral oil by homolog (Phase III and Phase IV results)................................................... 11 PCDF and PCDO formation from trichlorobenzene trans former fluid (Phase IV results) ................................................... 15 PCDF and PCDD formation from trichlorobenzene trans former fluid (Phase III and Phase IV results)..................... 16 PCOF formation from Wecosol....................................................... 17 Tetra- and pentaCDFs in sample 11-19-94-WEC .............................. 18 Hexa-, hepta-, and octaCDFs in sample 11-19-94-WEC......... 19 PCDF formation from OCDF-spiked feed, expressed as percent of OCDF fed into system................................................... 21 Tetra- and pentaCDFs in sample 11-30-100-0CDF .......................... 22 Hexa-, hepta-, and octaCDFs in sample 11-39-100-0CDF. ... 23 Number 1 2 3 4 5 6 LIST OF TABLES Title Operating conditions for Phase IV tests ...................................... PCDF formation from PCB-spiked mineral oil......................... Percent conversion PCB to PCDF.................................................. PCB destruction efficiencies for PCB-spiked mineral oil . . PCDF formation from non-PCB dielectric fluids and OCDF. . . PCOO formation from non-PCB dielectric fluids and OCDF. . . Page 5 7 8 10 13 14 iv MONS 213626 I. INTRODUCTION The Environmental Protection Agency (PA) has issued an Advance Notice of Proposed Rulemaking (ANPR) (USEPA 1984a) and proposed rule {USEPA 1984b) to gather data on the specific risks posed by fires involving electri cal transformers that contain polychlorinated biphenyls (PCBs) and also on mechanisms for mitigating or eliminating these risks. A work assignment was issued to Midwest Research Institute (MRI) to support EPA's data-gathering activities under the ANPR. Specifically, MRI was asked to study the combus tion of transformer dielectric fluids to investigate the potential for forma tion of toxic products such as polychlorinated dibenzofurans (PCDFs) and poly chlorinated dibenzo-p-dioxins (PCDDs). A report (Erickson et al. 1984) pre sents the results of previous work completed on this work assignment. This report describes the results of a series of experiments which were conducted to augment the data presented in the previous report (Erickson et al. 1984). The work presented here includes both repeat runs of those pre viously reported and also investigations of materials not previously tested. The next section presents a summary of the results. Section III presents the experimental methods. Section IV presents the results of the tests performed with the dielectric fluids. II. SUMMARY Two types of experiments were performed during Phase IV of this project. First, a series of repeat runs were made under identical conditions to those previously reported (Erickson et al. 1984). In these runs, the feed oil was mineral oil spiked with individual PCB congeners as in Phase II, and mineral oil spiked with Aroclor 1254 as in Phase III. Also during Phase IV, repeat runs were made using a trichlorobenzene dielectric fluid. The second group of Phase IV runs were performed to investigate PCDF and PCDD formation from the combustion of other non-PCB containing dielectric fluids which had not previously been tested. The three dielectric fluids which were tested were tetrachloroethylene (WecosolG), a paraffinic high temperature hydrocarbon (RTEmp), and an esterified high temperature hydrocarbon (Dielectric fluid HT-310-S). Finally two runs were made in which the feed oil consisted of mineral oil spiked with octachlorodibenzofuran (OCDF). These runs were made to better characterize the chemistry of PCOF formation. The results of the repeat runs correlate well with the previously reported results. The formation of PCOFs and PCDDs from the PCB-spiked min eral oil, as well as the calculated destruction efficiencies for PCBs, closely match the previously reported results. The repeat chlorobenzene runs show higher levels of PCOF formation than in Phase III. However, several concen trations in the previous report are "greater than" values; hence, comparison is difficult. I MQNS 213627 Significant amounts of PCDFs and PCDDs were formed from the tetrachloroethylene fluid. The two high temperature hydrocarbon fluids did not produce PCDFs or PCDDs. Figure 1 summarizes the conversion efficiency of dielectric fluid to PCDF for the different dielectric fluid types tested in Phases III and IV. It appears that, under these thermal destruction condi tions, the extent of PCDF formation varies among dielectric fluids by several orders of magnitude. The highest PCDF formation was noted for PCB-containing dielectric fluids, and the least formation was observed in tetrachloroethylene. It should be noted that during Phase II the thermal combustion system was op timized for PCDF formation from PCBs. The results for the OCDF-spiked feed oil runs showed formation of a number of lower chlorinated PCDF homologs with a variety of isomers within each homolog. III. EXPERIMENTAL METHODS A. Thermal Combustion System 1. Description MRI has developed a bench-scale thermal combustion test system which can be used to examine various combustion processes. It has also been used to provide data on the incinerabi1ity (i.e., destruction efficiency) of haz ardous compounds in solid or liquid waste material, and to provide data on products of incomplete combustion that may be formed. This system can pro vide combustion data on gram-quantity samples of materials in either solid or liquid form or even semisolid materials, such as tars. In contrast, other related systems often can handle only very small quantities of pure compounds. The system is described in detail in a previous report which pre sents the results of previous work on this work assignment {Erickson et al. 1984). Briefly, the system consists of a volatilizing/pyrolysis heater for the sample, an air preheater furnace, and the main combustion furnace (all electrically heated). Separate volatilization/pyrolysis furnaces are used for solid/semisol id feed and for liquid feed. Gas flow through the combus tion furnace is laminar and can be varied to provide different gaseous resi dence times. The combustion temperature can also be varied, up to a maximum of 1200C (2200F). The liquid feed rate, which is controlled by a syringe pump, can be varied over a nominal range of 1 pL/min to 1 mL/min. Primary operating conditions that can be varied and controlled in this system are temperature, oxygen concentration, and residence time. For this program, the system has been operated using continuous injection of liquid feeds. The 02, C02, and CO concentrations in the effluent gases were con tinuously monitored during each run. Semivolatile organic compounds were also collected in the effluent stream by adsorption and concentration in an XAD-2 sampling trap. 2 MONS 213628 PCDF# PCDDS Conversion Efficiency (g PCDF/g Feed or g PCOD/g Feed)I Figure 1. Suninary of conversion efficiencies for total PCOFs from Phase III and Phase IV runs. MONS 213629 I 2. -Operating Conditions The pertinent operating conditions are listed in Table 1. The ther mal combustion system was operated under the conditions optimized for PCOF formation from PCBs and used in all of the Phase III experiments described previously (Erickson et al. 1984). However, it is recognized that the optimal conditions for PCOF formation from other compounds are probably different. The key operational parameters were a combustion temperature of 675C, with a residence time of 0.8 s, with 8% excess oxygen. All samples were fed at a rate of 14 pL/min. B. Chemical Analysis Samples were analyzed as described in the previous report {Erickson et al. 1984). Each effluent sample consisted of two parts, the XA0-2 resin cartridge and a solvent rinse of the sample collection apparatus. The XA0-2 samples were spiked with 13C-surrogates and Soxhlet-extracted. This extract was combined with the associated solvent rinse to make a combined effluent extract. The combined extract was evaporatively concentrated to 2 m!_. Onehalf of each extract was cleaned by chromatography on acidified silica and acidified alumina. The cleaned extracts were analyzed for PCDFs and PCDDs. The remaining extract aliquot was analyzed for PCBs. Some of these extracts were also screened for other chlorinated organics. The high resolution gas chromatography/electron impact mass spec trometry (HRGC/MS) analysis of these effluent extracts was performed using selected ion monitoring. The analytical conditions used were: . Column: 30 m x 0.25 mm fused silica column, wall-coated with DB-5 Column Temperature: 100C (1 min hold) to 325C at 10C/min Injector: Grob-type, 45 s splitless, 280C Electron Energy; 70 eV C. Selection of Compounds for Evaluation 1- PCBs Five repeat experiments were performed in which the feed oil was PCB-spiked mineral oil. In three of these experiments (runs 90-92), the min eral oil (Exxon HPLX 355077) was spiked with 50 pg/g each of 2,3,5,6-tetra-, 3,3',4,4',5,5'-hexa-, and 2,2',4,4',6,6'-hexachlorobiphenyl. These compounds were purchased from Ultra Scientific. Runs 90-92 were performed under the same conditions as run 26 reported from the previous work. In two experiments (runs 97 and 98), the mineral oil (Exxon HPLX 355077) was spiked with 50 pg/g of Aroclor 1254 (Monsanto). These two runs are duplicates of runs 45 and 46 from the previous work. 2. Chlorobenzene A chlorobenzene dielectric fluid was fed during two runs (runs 106 and 107). This chlorobenzene fluid (Electro-Chem FR-15, Standard Chlorine Chemical Company in Kearny, NJ) was determined to contain mostly trichloro benzene isomers with some tetrachlorobenzene. This is the same chlorobenzene fluid which was previously tested as runs 57 and 58. 4 HONS 213630 Table 1. Operating Conditions for Phase IV Tests Feed material Run no. Combustion Run Excess Residence Combustion Pyrolysis temperature tine oxygen time C02 CO efficiency temperature (C) (min) (X) (s) (%) (*) (X) (C) PCB congeners PCB congeners PCB congeners None Tetrachloroethylene Tetrachloroethylene None Aroclor 1254 Aroclor 1254 Mineral oil OCDF OCDF OCDF HTH (para) HTH (ester) None Trichlorobenzene Trichlorobenzene None 11-14-90-M+M+M 11-14-91-M+M+M 11-16-92-M+M+M 11-16-93-M0(B)a 11-19-94-WEC 11-20-95-WEC ll-20-96-WEC(B)a 11-28-97-M50 11-28-98-H5Q ll-29-99-M0D 11-30-100-0CDF 11-30-101-0CDF 11-30-102-0CDF(B) 12-3-103-HTH(P) 12-4-104-HTH(E) 12-4-105-HTH(B) 12-5-106-CLBZ 12-5-107-CLBZ 12-5-108-CLBZ(B) 678 678 678 677 676 676 676 677 677 678 678 679 677 676 677 676 677 677 677 58 7.9 60 7.9 61 7.9 55 7.9 60 7.8 57 8.0 56 8.0 61 7.9 57 8.0 61 7.9 37 7.9 35 7.9 55 7.9 44 7.9 45 8.0 45 8.0 16 7.8 16 8.1 61 7.9 0.80 0.81 0.79 0.79 0.80 0.79 0.80 0.82 0.81 0. 79 0.81 0.78 0.77 0.79 0.81 0.81 0.79 0.78 0.78 0.22 0.21 0.27 0.07 0.08 0,07 0.06 0.12 0.12 0.13 0,14 0.15 0.06 0.09 0.12 0.07 0.08 0.07 0.07 0.37 0.40 0.29 0.0005 0.03 0.01 0.0005 0.32 0.33 0.52 0.33 0.33 0.0003 0.09 0.21 0.0002 0.16 0.16 0.0009 37 34 48 99 70 85 99 27 26 19 29 30 99 47 35 99 32 29 98 397 397 397 397 397 397 397 397 397 397 397 398 398 444 444 445 397 397 397 ^Runs with "(B)" suffixes are blank runs with no feed. Mineral oil with no PCBs added. HONS 213631 3. Wecosol This dielectric fluid, containing tetrachloroethylene (> 99%), was also tested on runs 94 and 95. It was obtained from Westinghouse Corporation, Pittsburgh, PA. 4. HTH Two high temperature hydrocarbon dielectric fluids were tested on runs 103 and 104. The first type of fluid is a paraffinic hydrocarbon [desig nated HTH(P) in run 103] labeled "RTEmp." It was obtained from RTE Corpora tion, Waukesha, WI. The other fluid is an esterified hydrocarbon [designated HTH(E) in run 104]. It was labeled "Dielectric fluid HT-310-S" and was ob tained from Standard Chlorine Chemical Company, Kearny, NJ. 5. Octachlorodibenzofuran Two runs were completed (runs 100 and 101) using a feed which con sisted of 500 pg/g of octachlorodibenzofuran (0CDF) from Ultra Scientific in mineral oil (Exxon HPLX 355077). It was apparent from the previous work that a variety of PCDF congeners are formed from many precursors in the thermal combustion system. It was not apparent from this work, the available litera ture, or communication with other researchers, whether these PCDFs were formed directly from precursors or whether a highly chlorinated dibenzofuran (e.g., heptaCDF or octaCDF) was first formed and then dechlorinated. It was decided that using a feed oil spiked with 0CDF could provide insight about the chem istry of PCDF formation. IV. RESULTS AND DISCUSSIDN A. Continuous Monitoring Results Table 1 lists the thermal combustion system operating conditions for the tests completed during this phase of the program. This table shows the combustion temperatures, the percent excess oxygen measured in the combus tion effluent, the calculated residence time, the percent CD2 and percent CO measured in the combustion effluent, the calculated combustion efficiency, and the pyrolysis temperature. B. PCB-Containinq Matrices 1. PCB Isomers In three runs (Nos. 94, 95, 96), the feed oil consisted of mineral oil spiked with 500 jjg/g each of the three PCB isomers 2,3,5,6-tetra-, 3,3'4,4' ,5,5'-hexa-, and 2,2',4,4(.B.e'-hexachlorobiphenyl (replicates of run 26 in the previous work). The results of analysis of PCDFs in these runs are listed in Table 2. Table 3 lists the conversions of PCBs to PCDFs. The literature (Buser et al. 1978; Buser and Rappe 1979) suggests that each of the three PCB isomers produces specific PCDF isomers as shown below: 6 HONS 213632 Table 2. PCDF Formation from PCB-Spiked Mineral Oil Run no. MonoCDF DiCDF TriCDF TetraCDF PentaCDF HexaCDF HeptaCOF OctaCOF PCDFs3 (ng) (ng) (ng) (ng) (ng) (ng) (ng) (ng) (ng) 1M4-90-M+M+M 11-14-91-M+M+M 11-16-92-M+M+M. ll-16-93-MQ(B)C 11-28-97-M50 11-28-98-M50 11-29-99-MO 770 810 810 < 5ri - 550 2,100 520 4,50D < 5 3.20D <5 <5 --- 1,400 2,600 2,000 82 250 190 < 10 240 320 830 73 30 20 < 10 73 < 30 28D 85 < 30 31 < 3D < 20b < 20 < 20 110 < 20 16 < 20 < 10 < 10 < 10 12 < 10 < 10 < 10 5,100 8,800 7,100 360 280 240 0 ^The not detected values (< X) were considered to be zero for calculating total PCDF concentration. Not detected; estimated method quantitation limit is given, jluns with "(B)" suffixes are blank runs with no feed. - = Not analyzed. HONS 213633 Table 3. Percent Conversion PCB to PCDF Run no. MonoCDF Conversion efficiency (X) DiCDF Conversion efficiency (X) TriCDF Conversion efficiency (X) TetraCDF Conversion efficiency (X) PentaCDF Conversion efficiency (X) HexaCDF Conversion efficiency (X) HeptaCDF Conversion efficiency (X) OctaCDF Conversion efficiency (X) Total PCDF (X) 11-14-90-M+M+M NCa NC 0.61 D.20 0.035 0.021 NC 11-14-91-M+M+M NC NC 1.14 0.37 0.046 O6 NC NC 0. 37 NC 0.85 11-16-92-M+M+M NC NC 0.88 0.29 0.12 0.077 NC NC 0.39 11-28-97-M50 -- 0.69 0.082 0 0 0 0. 77 11-28-98-M50 0.55 0.058 D. 091 0.047 0 0.70 ^NC = Not calculated; conversion efficiencies only calculated for proposed reaction mechanisms. c0 = not detected. = not analyzed MGNS 213634 2,3,5,6-Tetrachlorobiphenyl 1,2,4-Trichlorodibenzofuran 3,3',4,4',5,5*-Hexachlorobiphenyl 2,3,4,6,7,8-Hexachlorodibenzofuran 2,2' ,4,4',6,6'-Hexach1orobipheny1 1,3,7,9-Tetrachlordibenzofuran 1,3,4,7,9"Pentachlorodibenzofuran The conversion efficiencies listed in Table 3 assume the above reactions apply. As noted in the previous report, only one isomer each of triCDF and tetraCOF was present in the samples. However, several pentaCDF and hexaCDF isomers were identified, indicating that either the chemistry of the PCB-to-PCDF con version is more complex than originally thought or the PCDFs are degrading and rearranging after the initial formation. A total PCB to total PCDF con version is also listed for each run in Table 3. No PCDDs were detected in these samples. The PCDF formations in the three M+M+M runs (90, 91, and 92) were similar. The results are also in agreement with those previously obtained under these experimental conditions (Table 14 in Erickson et al. 1984). Al though the current results are not as high as those in the previous report, they are higher than the amounts observed under any other experimental condi tions. Thus, the current results corroborate the conclusion reached in the previous report that combustion at 675C for 0.8 s with 8% excess oxygen is optimum for formation of PCDFs from PCBs. The combustion effluents from these PCB-spiked mineral oil runs (Nos, 90, 91, and 92) were also analyzed for PCBs. From these results, the PCB destruction efficiencies were calculated for each run using the formula presented in the previous report. The destruction efficiencies are shown in Table 4. These results (91, 93, and 85%) compare well with the previously reported destruction efficiencies (Table 30 in Erickson et al. 1984). 2. Aroclor 1254 In two runs (97 and 98) the feed oil consisted of mineral oil spiked with 50 pg/g of Aroclor 1254 (Monsanto Corporation). These runs duplicate runs 45 and 46 from the previous work. The results of the analysis of PCDFs in these runs are also shown in Table 2. These results are generally compar able to those previously reported. The calculated conversion efficiencies for PCS to PCDF are shown in Table 3. No PCDDs were found in the samples, A conversion efficiency is given for each PCDF homolog. Unlike the conversion efficiencies calculated in individual PCB isomers, these conversion efficien cies were calculated using the total concentration of Aroclor 1254 feed. Figure 2 shows a plot of the nanograms of each PCDF homolog detected in these runs per milliliter of spiked mineral oil feed versus homolog. This figure combines the data from this phase of work with a similar graph from the pre vious report (Figure 22 in Erickson et al, 1984). The overall formation efficiency is similar to that previously reported. However, the PCDF distri bution in the current work tends toward higher chlorination. 9 MGNS 213635 Table 4. PCB Destruction Efficiencies for PCB-Spiked Mineral Oil Run no. Destruction efficiency (SJ) 11-14-90 M+M+M 11-14-91 M+M+M 11-16-92 M+M+M 11-28-97 M50 11-28-98 M50 81 93 85 73 72 10 MONS 213636 10,000 ng P C D F/m L Fluid __l________ 1__________ I_________ I---------------1_________ I-------------- 1-------------- l_l Mona Di Tri Telfa Penia Hexa Hepia Ocfa PCDF Figure 2. PCDF formation in PCB-spiked mineral oil by homolop (Phase III and Phase IV results). Closed symbols are averaqes of two values; open symbols are single determinations; missing points are no data. Phase IV data are superimposed on Phase III data, previously published as Figure 22 in Erickson et al. (1984). MGNS 21363? The combustion effluent from the Aroclor 1254-spiked feed runs (Nos. 97 and 98) was also analyzed for PC8s. The PC8 destruction efficiency was calculated as described in the previous report. These results are shown in Table 4. These two calculated destruction efficiencies (73 and 72%) compare well with the calculated destruction efficiencies reported previously (Table 30 in Erickson et al. 1984). C. Non-PCB Dielectric Fluids 1. Chlorobenzene Fluid In runs 106 and 107 the feed was a non-PCB containing chlorobenzene dielectric fluid (RF-15 from Standard Chlorine Chemical Company). These runs duplicate runs 67 and 58 from the previous work. The major compounds identi fied in the analysis of the combustion effluents include dichloro-, trichloro-. tetrachloro-, pentachloro-, and hexachlorobenzene. No PC8s were detected in chlorobenzene combustion effluents. The results of the analysis of PCDFs in these runs are shown in Table 5. The PCDF levels detected for runs 106 and 107 are higher than pre viously reported (runs 57 and 58 in Erickson et al. 1984). However, several concentrations in the previous report are "greater than" values; hence, com parison is difficult. Table 6 lists the amounts of PCDOs formed from these chlorobenzene dielectric fluid runs. The total amount and overall distribution of PCDDs detected are comparable to the levels previously reported (runs 57 and 58 in Erickson et al. 1984). Figure 3 shows a plot of the nanograms of each PCDF and PCD0 homolog detected in these runs per milliliter of chlorobenzene fluid fed versus homolog. Figure 4 combines these data with a similar plot from the previous report (Figure 25 in Erickson et al. 1984). The isomeric dis tributions of the PCDFs and PCDDs in these runs were similar to those from the previous runs (see Figure 20 in Erickson et al. 1984). 2. Wecosol As shown in Table 5 and Figure 5, fairly consistent amounts of tetraCDF through octaCDF were formed from thermal reaction of Wecosol, While the conversion efficiency (Figure 1) is low relative to pure PCBs, it does correspond roughly to the PCDF formation from 500 ppm Aroclor 1254 (Erickson et al, 1984). Low amounts of hexa- through octaCDD were observed (Table 6) in the Wecosol runs. However, only slightly lower amounts of the PCDDs were found In the run immediately following the two Wecosol runs. Therefore, the significance of the PCDD values cannot be determined from these data. Figures 6 and 7 present extracted ion current profiles of the PCDFs. The isomeric distribution from the tetrachloroethylene precursor is slightly different from those previously observed from reaction of PCBs or trichloro benzene (Figures 10-20 in Erickson et al. 19B4). 12 HONS 213630 Table 5. PCOF Formation from Non-PCB Dielectric Fluids and OCDF Run no. MonoCDF (ng) DiCDF (ng) TriCDF (ng) TetraCDF (ng) PentaCDF (ng) HexaCDF (ng) HeptaCDF (ng) OctaCDF (ng) PCDFs (ng) 11-19-94-WEC 11-20-95-WEC . ll-20-96-WEC(B) 11-30-100-0CDF 11-30-101-0C0F ll-30-102-0CDF(B) 12-3-103-HTH(P) 12-4-104-HTH(E) 12-4-105-HTH(B)C 12-5-106-CLBZ 12-5-107-CLBZ 12-5-108-CLBZ(B)c a - - - - - 1,100 570 84 - - - - 5,900 1,700 140 - - - - 32,000 3,700 240 630 2,400 < 10 3,600 3,700 170 33 < 10 1,100 79,000 32,000 610 600 2,400 91 6,200 4,300 120 < 10 < 10 1,500 93,000 48,000 960 920 1,800 140 29,000 42,000 190 25 < 30 1,000 9,800 22,000 1,300 1,100 1,500 150 41,000 50,000 260 35 40 340 19 690 1,300 270 320 42 14,000 20,000 150 62 < 10 80 < 10 70 750 3,500 8,400 420 94,000 120,000 890 160 40 4,020 220,000 109,000 5,400 jj- = Not analyzed. Runs with suffixes "(B)" are blank runs with no feed. Extracted after the OCDF and CLBZ samples (Run Nos. 11-30-100-0CDF, 11-30-101-0CDF, 12-5-106-CLBZ, and 12-5-101-CLBZ), Observed PCDFs may be carryover in glassware or carryover in thermal combustion system. MONS 213639 Table 6. PCDD Formation from Non-PCB Dielectric Fluids and OCDF Run no. MonoCDD (ng) DiCDD (ng) TriCDD (ng) TetraCDD (ng) PentaCDD (ng) HexaCOD (ng) HeptaCOD (ng) OctaCDD (ng) PCODs (ng) 11-19-94-WEC 11-20-95-WEC ll-20-96-WEC(B)b 11-30-100-0CDF 11-30-101-0CDF ll-30-102-0CDF(B) 12-3-103-HTH(P) 12-4-104-HTH(E) 12-4-105-HTH(8) 12-5-106-CLBZ 12-5-107-CLBZ 12-5-108-CLBZ(B) _a - 24 81 <5 . < 10 -- < 10 --- < 10 < 10 ---- < 10 < 10 < 10 -- < 10 -- < 10 40 1,100 600 150 350 680 < 5 < 5 < 10 < 10 < 10 < 10 < 10 < 10 < 10 < 10 < 10 < 10 < 10 63 < 10 57 51 < 30 < 30 < 30 < 30 < 30 < 30 < 30 < 30 94 < 30 130 72 72 < 20 < 20 < 20 < 20 < 20 < 20 < 20 < 20 < 20 120 49 46 < 10 < 10 < 10 < 10 < 10 < 10 < 10 < 10 < 10 310 170 120 < 80 < 80 < 80 < 80 < 80 < 80 1,800 1,400 < 100 = Not analyzed. Runs with suffixes "(B)" are blank runs with no feed. HONS 213640 ng P roduct/m L Fluid Not Detected Mono Tetro Penta Homo log Hepta Figure 3. PCDF and PCDD formation from trichlorobenzene transformer fluid (Phase IV results). Closed symbols are averages of two values; open symbols are single determinations. HONS 213641 ng P roduct/m L Fluid Figure 4. PCDF and PCDD formation from trichlorobenzene transformer fluid (Phase III and Phase IV results). Solid lines are Phase IV re sults; broken lines are Phase III results, originally published as Figure 25 in Erickson et al. (1984). Closed symbols are averages of two values; open symbols are single determinations. HONS 213642 ng PCDF/m L Fluid 10,000 1,000 100 10 - Mono Di _u _L Tri 'Tetra Pent a Hexa Hepta Octo PCDF Figure 5. PCDF formation from Wecosol. Closed symbols are averages of two values; missing points are no data. HONS 213643 KID NASS CHRONATOGRAHS OATAi B291A14R1 *1 SCANS 1905 TO 1239 91/14/95 12:33)99 CALI) HID399A99R1 *2 SAfflEi RUN 11-19~94*4CC> SONIFIED* 2UL INJ COHOS, i -2299EHU 79EU 1NA 30THK3 199-Itt*325-10/-495S GROB RANCEi C 1, 1 LABEL) H 0, 4.9 QUAH) A 9. 1.9 J 9 BASE) U 28. 3 1039 17:32 1199 18)22 1139 19)13 1299 28)13 Figure 6. Tetra- and PentaCOFs in sample 11-19-94-WEC. 1230 SCAN 20)53 TINE HONS 213644 NIO NASS CHROMATOGRAMS QATAi 0201A16R1 01 SCANS 1850 TO 1350 9Ut6^S 10i22i80 CALli HIB395A16R1 *3 SAMPLEi RUN 11-19-S4-HEC FOR CL6-0.SONIFIED,2UL INJ COWS.: -2200EW 70EU 1NA 39HS5 108-1W-325-I0/-45SS ffiOB RANGE: C 1. 1 LABELi N 8, 4.0 QUANl A 0. 1.0 J 0 BASEi U 28, 3 36.0-1 HexaCDFs 473606. 373.000 * 0.500 100.0-1 408 30.1-. 1058 20:34 I HeptaCDFs JuL^l JL OctaCDFs 409472. 407.000 t 0.500 147456. 443.000 t 0.500 1100 21i33 1190 22:32 1200 23:31 1250 24:29 1300 25:20 Figure 7. Hexa-, Hepta-, and OctaCDFs in sample 11-19-94-WEC. 1350 SCAN 26:27 TIME MONS 213645 These samples were also analyzed by full scan HRGC/MS. A large amount of tetrachloroethylene was observed. Chlorinated benzenes were also observed. A variety of nonchlorinated compounds were also identified, includ ing smaller polynuclear aromatics, hydrocarbons, phthalate esters, and alde hydes. A more detailed identification of these products will be reported at a later date. 3. HTH No appreciable amounts of PCDFs or PCDDs were found in the reaction products of HTH (ester) or HTH (para) runs, listed in Tables 5 and 6. The small amounts of PCDFs found in run 103 were apparently carryover from the previous OCDF runs. This conclusion is supported by the fact that the isomer patterns in the HTH and OCDF runs were similar. These samples were also analyzed by full scan HRGC/MS. A variety of C8*C20 hydrocarbons, smaller polynuclear aromatics and their alkyl adducts, aliphatic alcohols, aldehydes and ketones were observed. A more detailed identification of these products will be reported at a later date. 4. Octachlorodibenzofuran Two runs, followed by a blank run, were conducted with OCDF in min eral oil at 500 pg/mL. As discussed in Section III.C.5, the objective of these experiments was to assess the potential for formation of lower chlori nated homologs from OCDF. As noted in Table 5 and Figure 8, substantial amounts of the lower PCDF homo logs were formed. Only about 8% of the OCDF feed passed through the reaction system unchanged. No PCDDs were detected (Table 6). Preliminary, nonquantitative analyses indicated that small amounts of mono- through triCDFs were also formed. Figures 9 and 10 present extracted ion current profiles of the PCDFs formed from the OCDF feed. The isomeric distribution of the PCDFs has some similarities to those observed from combustion of tetrachloroethylene (Figures 6 and 7), PCBs, or trichlorobenzene (Figures ID-2D in Erickson et al. 1984). Further work is needed to identify specific similarities and differences. D. Quality Assurance and Quality Control A variety of QA and QC activities were conducted throughout the course of this work to assure that the results were acceptable. The project records were inspected by MRI's Quality Assurance Unit and any deficiencies were corrected. The data were spot-checked by the work assignment leader and reviewed by the Quality Assurance Unit. Various routine QC activities were conducted to provide data on the data quality. All thermal combustion runs were conducted in duplicate (see Tables 2, 5, and 6) to provide a measure of precision. Isotopically labeled compounds were added to assess the overall accuracy. The recovery of 13C-TCDD averaged 66 23% for 16 samples, based on external standards. Similarly, recoveries for l3C-TCDF averaged 69 t 17% and 13C-0CDD averaged 45 15% (14 samples). The differences in number of samples arose from interferences in certain samples which prevented quantitation of one or more of the surrogates. 2D HONS 213646 30 20 10 % Conversion --1------------- --------L---------------------t Mono Di Tri ........ ........1-------------------- 1--------------------- 1_____________ i______________Lj Tetro Pent a Hexa Hepfa Octa PCDF Figure 8, PCDF formatior. from OCDF-spiked feed, expressed as percent of OCDF fed into system. Closed symbols are averages of two values; missing points are no data. HONS 213647 mO MASS CWOHATOCRAMS OATAi 8201A15R3 *1 SCANS IMS TO 1238 01^13^85 ll:16i00 CALIi HID388A83R1 2 SAMPlEi RUN 11-30-100-OCOF PCOW/a4-3 SONICATED 2UL IHJ COHOS, t -2200EW 78EU IMA 30M-O85 108-1**323-10/-43SS GROB RANCEi G 1, 1 LABELi N 0. 4.0 BUANi A 0/ 1.0 J 8 BASEi U 28. 3 1858 17:32 1188 10t22 1138 19H3 1288 28i83 Figure 9. Tetra- and PentaCDFs in sample 11-30-100-0CDF. 1230 SCAN 20.53 TIME HONS 213648 MID MASS CHROMATOGRAMS DATAi 8201A17R2 #1 SO*6 1850 TO 1300 01/17/85 0(54100 CALIi HID355A16R1 13 SAMPLE: RUN 11-38-180-OCDF FOR CL6-0.SONIFIED# 2UL IHJ CK?S. i -220OEHU 70EU IMA 30H-O03 100-1W-323-10/-455S GROB RANGE: G 1, 1 LABEL: N 0. 4,0 QUANi A 0- 1.0 J 0 flASEt U 28, 3 04.3-, 10371000. 374 100.0-1 rUo, 4es 62.2-1 HexaCDFs + A-p T =qp 373.000 1 0.580 T 12304300. 407.000 l 0.580 --I 7651320. 444 OctaCDFs 443.000 t 0.500 I- -r "=g" T-I | I 1050 20(34 1100 21133 i ( f. I... 1150 22(32 1200 23:3 1 1250 24(29 1300 25(28 Figure 10. Hexa-, Hepta-, and OctaCDFs in sample 11-39-1QO-OCDF. 1300 SCAN 26(27 TIME MOMS 213649 The values for the native PCDFs and PCDDs presented in this report have been corrected for the surrogate recovery, as described in the Chemical Analysis Section in the previous report (Erickson et al. 1984). V. REFERENCES Erickson et al. 1984. Thermal degradation products from dielectric fluids. Interim report. Report EPA-560/5-84-009, NTIS PB85/38535. Washington, DC: Office of Toxic Substances, U.5. Environmental Protection Agency. Contract 68*02-3938. U5EPA. 1984a. Polychlorinated biphenyls (PCBs); manufacture, processing, distribution in commerce and use prohibitions; use in electrical transformers. Advanced notice of proposed rulemaking. (49 FR 11070-11083). USEPA. 1984b. Polychlorinated biphenyls (PCBs); manufacture, processing, distribution in commerce and use prohibitions; use in electrical transformers. Proposed rule. (49 FR 39966-39989). Buser HR, Bosshardt H-P, Rappe C. 1978. Formation of polychlorinated dibenzofurans (PCDFs) from the pyrolysis of PCBs. Chemosphere 7(1):109-119. Buser HR, Rappe C. 1979. Formation of polychlorinated dibenzofurans (PCOFs) from the pyrolysis of individual PCB isomers. Chemosphere 8(3):157-174. 24 HONS 213650 TECHNICAL REPORT DATA (Pitot* rood fNucriofii on thtrtvtnt boforr computing) ' t, NEfOUTNO. EPA-560/5-85-022 A. TITLE AMO 9U0TITLC Products of Thermal * Degradation of Dielectric Fluids 3. RtOFl KNT'S ACCCSflON NO, 8. REFORT OAT* May 1985 , PERFORMING ORGANIZATION COO* 7. AOTHOAOI 8201A23 1. PERFORMING ORGANIZATION REFORTNO. Stephen E. Swanson* Mitchell D. Erickson, Leslie Moody Interim Report No. 2 . PERFORMING ORGANIZATION NAME AND AOORESS Midwest Research Institute 425 Volker Boulevard Kansas City. Missouri 64110 10. FROORAM ELEMInT n6.-------------------------------- Work Assignment No. 23 11. contrACTAUAWT nA.------------ ------------------- EPA Contract No. 68-02-3938 11. SPONSORIN') AOENCY NAME ANO AOORESS Field Studies Branch, TS 798 Office of Toxic Substances, U.S. 401 M Street, S.W. Washington, DC 20460 EPA 13. TYFE OF REFORT ANO PCHIOO COVEREO Interim (11/84 - 5/85) 14. SFONSORINO AQINCv COOE IS, SUPPLEMENTARY notes The EPA Work Assignment Manager is Oaniel T. Heggem, (202) 382-3990. The EPA Project Officer is Joseph J. Breen, (202) 382-3569. is.abstract 7^s report describes the results of a series of experiments which were con ducted to augment the data presented in a previous report (EPA 560-5-84-009). The work presented her* includes both repeat runs of those previously reported and also investi gations of materials not previously tested. The results of the repeat runs correlate well with the previously reported results. The formation of PCDFs and PCOOs from the PCB-spiked mineral oil, as well as the calculated destruction efficiencies for PCBs, closely match the previously reported results. The repeat chlorobenzene runs show higher levels of PC0F and PCD0 formation than previously. However, several concentra tions in the previous report are "greater than" values; hence, comparison is difficult. Significant amounts of PCOFs and PCOOs were formed from the tetrachloroethylene fluid. The two high temperature hydrocarbon fluids did not produce PCDFs or PCOOs. It appears that, under these thermal destruction conditions, the extent of PC0F formation varies among dielectric fluids by several orders of magnitude. The highest PC0F formation was noted for PCB-containing_dielectric fluids (about 0,01% of the amount fed), trichloro benzene had about 5 x 10 4 conversion efficiency, and the least formation was observed in tetrachloroethylene (about 4 x 10 ). It should be noted that the thermal combus tion system was optimized for PCDF formation from PCBs and the optimal conversion con ditions for the other fluids may produce higher PCDF yields. The results for the 0CDF- spiked feed oil runs showed formation of a number of lower chlorinated PC0F homologs with a variety of isomers within each homoloq. .. it. KEY WORDS AND (DOCUMENT ANALYSIS (. DESCRIPTORS b. IOENTIPIERS/OPEN ENDED TERMS C, COSATi t feiU/Group PCBs; PCDF; PCD0; 0CDF; Polychlorinated biphenyl; Polychlorinated dibenzofuran; Polychlorinated d1benzo--dioxin; Tetrachloroethylene; Trlchlorobenzene: Dielectric fluid; Combustion; Pyrolysis; Transformer fires; PCB fires IS. DISTRIBUTION STATEMIN+ Uni imited IS. SECURITY CLASS/fMlMtW't)' UNCLASSIFIED 20. SECURITY CLASS (TMi UNCLASSIFIED ii. no. of uraii 30 12.FRICC ESA P 2210.1 (Rav. 4--77) phiviou* (Dition ii gngnti HONS 213651 Unle<J S'ales tnviionmpn'at Piolechon Agency Oilice ol lOfctc Subslances Washington DC 20460 HONS 213652