Document YGa8aVyYpG5rzNDZOoYpv64Ly

Analytical Chemistry Special Study 71-2 Job No. 13480 HC3 1016 - AN ENVIRONMENTALLY COMPATIBLE AROCLOR INTRODUCTION The objective of thie report is to bring together all the informa tion, so far generated by Monsanto, at al, that supports the contention that an environmentally compatible Aroclor can be manufactured. The product would be designed for use in areas where its industrial properties are unique enough to merit close control of the amount of material allowed to escape into the eco system. SUMMARY The information present in this special study report demonstrates that, from an environmental viewpoint, MCS 1014 is at least 10 times better than the current product Aroclor 1242 and in turn 75 times bettar than Aroclor 1254. The above conclusion is based on the rather simplified aesumption that the major environmental hasard associated with polychlorinated biphenyls (Pci's) is their ability to resist metabolic and non* metabolic degradation. The resistance of the PCl'e combined with their high lipid eolubility in turn leede to their undesirable biological build up toward the end of the exposed food chain. RESULTS AMP DISCUSSION Polychlorinated biphenyl products are produced by direct chlorina tion of biphenyl which means that there exists in all PCI products at some level every oonceivable isomer. The biphenyl ring structure (Figure Z) can have theoretically 0*10 chlorine atoms substituted on it in any of the positions designated by the numbers on the ring. Assuming that the phanyl rings can rotate freely about the 1,1'bond whatever the number and positions of chlorine substituents it can be calculated that there are 210 possible isomers. The distribution of these isomers according to the number of chlorines per biphenyl molecule is shown in Table X, column 1. Figure I 32 2' 3' HONS 021395 Special Study 71-2 Page 2 TABLE 1 Homolog No. of Cl Per Biphenyl Molecule Diet. of 0it, of Most Theoreti- Probable cal PC* PC* Isomers Isomers Oist. of Most Probable PC* Isomers Found in Nature Diet, of Most Probable PC* Isomers Co- Oxidised by C, Oist. of Identt fiable PCB Isomers Absent in Tissue Extracts 011 1 33 2 12 4 3 24 10 4 42 21 5 44 34 6 42 21 7 24 10 4 12 6 933 10 1 1 - 34 21 10 4 - * 1 3 5 11 4 5 1 - 1 3 9 4 - - - - - - Totalt 210 130 01 30 17 The number of possible isoaere esn bo rsducod from 210 to 130 by further aeeuaing thot tbs aost probsbls struoturss ors those where the nuaber of chlorine etosw on the two rings differ by not aore than one. The distri bution of the aost probable structures are shown in Table X, column 2. Of these 130 aost probable ieoaers, the ones of further interest are those that have 5-1 chlorine atoas per biphenyl aolecule. The reason for this lies in the fact that PCI's containing 5-1 chlorine atoas are the aost refractory toward degradation as witnessed by what has and is being found in *weathered" biological materials. This leaves a total of 81 isomers that are the oause of the undeeirable biological build up phenomenon. The isoaars of concern are listed in Table X, column 3. with this information in hand, it is instructive to discuss the homolog distribution of hroolor 1334. Aroclor 1242 and tha replacement fluid Hes- 1014. This distribution is shown in Table XX. Some simple arithmetic with the numbers in Table XX shows that of Aroclor 1254. '10* of Arcelor 1242 and only 'It of MCS 1014 are the refractory PCI isomers that are responsible for the biological build up. CONCLUSION *MCS 1014 can decrease the level of refractory PC* isomers currently being released to the environment from use Of Aroclor 1242 and Aroclor 1234 by factors of 10X and 7SX, respectively." To further verify the above conclusion, a number of research programs have been instituted which include studies of bacterial degradation of the products in question by natural and accumulated bacteria as well as some wort involving rat metabolism. HONS 02139O Homolog No. of Cl Per Biphenyl Molecule 0 1 2 3 4 5 6 7 9 10 Special Study ?i- 2 Page 3__________ TABLE II HOMOLOG DISTRIBUTION OF AROCLOR PRODUCTS Aroclor* 1254 0.05 0.04 0.32 0.74 22.99 47.31 19.75 4.42 3.94 Aroclor** 1242 0.01 0.70 15.50 49.40 24.SO 8.70 0.85 ** MCS** 1014 0.02 1.00 19.70 57.30 21.20 0.80 0.05 * Aroclor 1221 19.00 54.10 20.40 3.90 2.30 0.25 - - * * spectroeoopy Special Study Kean, S. N. 1beery to R. B. Keller, 1-32-71. Accumulated Bacterial Degradation* It haa been damonetrated in the laboratory that e number of tingle PCS iaomera and eiaple binary eixturea can be co-oxidised in the preeence of biphenyl by a biphenyl degrading orpaniea, Ct< The metabolic oxidation of biphenyl by Ct ie believed to occur aa ehown in Figure XX. The technique employed in theee etudiee ia a etandardicad that* flaak procedure described in detail in the referenced report. The reaulta of there etudiee have auqqeated that the etructure of the iMCL Review report, Riodegradability of Polyohlorinoted Biphenyls*, J. H. Mainprise, Reference No. MP10103. Pathwaya MONS 0*1397 Special Study 71-2 Page 4 ________ most highly chlorinated PCB that will undergo *t least primary degradation by C| is; Figure III Cl Furthermore* all other C* degradable PCS'a can be arrived at by progressively removing chlorine atoms from the structure in Figure ill. This means that of the 130 most probable PC* isomers, 30 alone can be co-oxidised by this single culture* C*. The distribution of these isomers .s shown in Table I, column 4. Long term exposure of MCS 1014 and Aroclor 1343 to C* has indicated that the order of degradability is MCS 1014>MCS 71?*>MCS 743* Aroclor 1343. Conclusion `The dominant isomers present in MCS 1014 can undergo at least primary bacterial degradation.* natural Sectorial Degradation Two techniques which ere believed to more closely simulate actual environmental situations are also ourrently under investigation, Semi-Continuous Activated Sludge Testing (SCAS) and river die-away (ADA) exposures. The decay of Aroclor 1331, Aroclor 1343 and Aroclor 13S4 exposed to the natural biological population of river water was briefly studied in the following manner. A five gallon supply of natural wstar was obtalnsd from the Meremec River, and aftnr allowing tha aadiment to aattla for two daya, the weter was decanted into another container* remixed* and 300 nl aliquots placed in the appropriate number of 14 oa. wide mouth bottles. The bottles were then spiked with 350 ppb of Aroclor 1331* Aroclor 1343* end Aroclor 1354 by injecting 0.5 ul of e 101 (w/v) solution In athsnol and 4 ppm of LAS rafaronea 13 (Dodscant-1) added as an interns1 standard. After swirling to mix* tha bottlas wars than loosely covered with foil and placed in a cardboard box. Duplicate distilled water controls were prepared with no LAS aa were river water and distilled water controls containing LAS but no Aroclor. `Chlorinated biphenyl test materials Intermediate in chlorine content with respect to MCS 1014 and Aroclor 1343. HONS 0il398 Special Study 71-2 fm 5________ On* bottle from each sot was than analysed on a weekly basis, Tha analysis consistad of extracting tha bottle and contants with three 50 ml portions of haxana, diluting or concentrating tha combined extracts to tha appropriata volume and maasuring tha rasidual Aroclor by alactron captura gas chromatography. Additionally, tha LAS was monitored by methylene blue chloroform extraction method. Neither Aroclor 1242 nor Aroclor 1254 disappeared at a measurable rata under tha conditions of this experiment. However, the results of the EC/GC analysis for Aroclor 1221 are shown in Table III. rigure IV is a normalised composite of the EC chromatograms for the Aroclor 1221 river water and distilled water exposures, rtgure V is just a plot of the disappearance rate. LAS disappearance was normal in all oases. TABLE III Aroclor 1221 Elver Hater Distilled water 244 121 77 24 249 147 152 101 Although HCS 1014 was not available at the timrn this study was carried out tha results are pertinent since MCE 1014 is intermediate in chlorine oontent with respect to Aroclor 1221 and Aclor 1242. The homolog distribution of Aroclor 1221 is shown in Table II, column 4. Conclusion "The EDA diseppearance rate of HCS 1014 should fall somewhere between those observed for Aroclor 1221 and Aroclor 1242," Semi-Continuous Activated Sludge Tests The details of the SCAS test procedure are outlined in Physical Chemistry Method 70*14. Sriefly, the test consists of observing the diseppearance rate of the material in question exposed to a bacterial eludes being feed a synthetic sewage sdxture and aerated. Some samples of the results obtained vie this test are ihwn in Table III to give the resder a feeling for the disappearnace rates which have been observed for similar oon-chlorinated aromatic materials. To date, the results from tests with HCS 1043", HCS loie, Aroclor 1242 and Aroclor 1254 have allowed the following conclu sions? to be drawni - Significant evidence of biodegradability was found for HCS 1043. Significance level used - 951. ^Analysis of Siodegradation Data", Statistics Spscial Study 70*22, J. D. Hinchen. M0NS 021399 Special study 7i-j Page 6 -MCS 1016 and Aroclor 1242 showed evidence of biodegradation but neither wee significant at 95%. -Aroclor 1254 showed no evidence of biodegradation. TABLE IV Exposure Teat Material Level Linear Alkyl Bensena Sulfonate (Dodecene-1) 20 Mg Biphenyl Isopropylstad Biphenyl Mixture Hydrogene ted Terphenyls 5 Mg 10 Mg 10 Mg Dieappeerence Beta (24 Hrs. >99% >95% 79% 49% Determination of PCB Residues in Rets red Aroclor 1242, Aroclor 1254, ia Xroclor 12Iff3-------------------------------------------------------------------1----------------------- The rat tissue samples were analysed after extraction by electron capture gas chroeatography as outlined in Analytical Chemistry Method 70*1. Upon cosipletion of the electron eapture work all tissue extracts, for each Aroclor fed, were combinad and concentrated. The concentrates were then further purified via liquid chromatography and subjected to high resolution gas chromatography on a support coated open tubular (S.C.O.f.) column to identify as many of the unaffected isomers and homologs as possible. The resulta of this study demonstrated that the reeidual PCS levels in all rat tissues (fet, kidney, anisele, and liver) decrease significantly as the degree of'chlorination and the dietary exposure level of the materiel fed decreeaed. Additionally, it was observed that the aaount of iaomeric alteration Increased as the degree of chlorination decreased reeulting in the fact that major PCI isoawre retained by the rats fsd Aroclor 124 2 were those predominantly praeent in Aroclor 1254 and Aroclor 1260. The dietribution of the PCS ieomera that ware not retained in the composite tieaua axtracta are ehown in Table II, column 5. Most important to note ie that the 4,4 * -dichloro and the 2,6-dichloro biphenyl ieomera, which cannot be theoretically eo-oxidised by the Ct bacteria, were metabolized and/or excreted by rata. 3"Determination of Polychlorinated liphenyl Residues in Ratsi From 30 Day Aroclor reeding Studies", Analytical Chemistry Special study 70-17, E. S. Tucker. ^ Q2lit00 Special Study 7 1-2 Page 7 Although the action of living organiaaw on polychlorinated biphenyls rapreaanta an important rout# for thair disappearance from tha nvlronmant, it la by no aaana tha only dagradation pathway avail abla. Many othar factora in tha anvironmant such aa intaraction with light, air, water, soil, duet, and haat which hava not baan invaatigatad may alao contributa to tha nonmatabolic decomposition of tha matariala in question. db Monaanto company Organic Chemicals Division Applied Soianoas faction St. Muia< Miaaouri 2/71 * B. f. Tuckar MQNS 021401 -- >].l. ONS C2UC2 nH* d ** -** e 1s ;-: 5* *i i. .i vi HONi oil'*03 r