Document R2Jk5qbDJRYr2x9Bor502Ndw7

'.iVffib'anto -C - `. I A *I October 28, 1975 _LlK. Chlorophenol Dioxin History " D.. R. Dill W. R. Bennet D. K. Lynch , J. F. Quinn --*I J T O : D. P. Roman - Following is a condensed summary on the history of my involvement on the chlorophenol dioxin problem, since its onset in 1970. The work described, for the most part, was carried out at the W.G.K. Plant by myself under the consultation and authorization of the Specialty Product Business Group R & D management (D. R. Dill, W. R. Richard).. This summary is by no means "complete," since a more detailed discussion of this work will be presented in a final report which will be written and published in the-near future.' This summary is being issued at this time to aid in decision making, with respect to future activities on the dioxin problem. Work first began on the chlorophenol dioxin-problem in early 1970. After analytical method development by Applied Scienci^a study was carried out with the following objectives: . 1) measure the dioxin concentrations in all Penta/Santobrite process and product streams 2) measure concentrations in competitive Santobrite and Penta 3 ) ` define possible ways to reduce or eliminate the dioxins The details of this study are reported.in reference No.- 2. In summary, the study revealed: J 1) Higher chlorinated dioxins(hepta CDD and octa CDD)are present in Santobrite and Penta. OCDD is present in greatest amounts. These dioxins are primarily formed during'the later'stages'of "chlorination. -'They are als formed but at a much slower rate, during molten storage pri^r to prilling. Small amounts of HCDD and OCDD can also form in penta oil solutions(Cyclo-s if held at high temperature over a period of time. (MDL 50. ppm) 2) Lower chlorinated dioxin(tetra CDD)was not detected in finished Pen .However, levels of about 1 ppm TCDD were detected in chlorination mass at t early stages of chlorinationT (.MDL 0.5 ppm) 3) Santobrite contains somewhat lesser amounts of dioxins than Penta. Some of the dioxins are removed in the Santobrite process. They are remove a insolubles in the Cone settler and also possibly as sublimables in the drying process. The insolubles are currently being sewered. 4) Dioxins were not detected -in-any of-the-Penta-or Santobrite -scrubbi . streams. .5) Competitive Penta 'and Santobrite are comparable in dioxin content t. Monsanto 's products^ 0 i i I i CiX_-i I L! i ' j Protective Order lO COUP Chlorophenol Dioxin History October 28, 1975 Page 7 DIOXIN PRECURSOR STUDY The most likely suspects for the unexplained CEF toxicity were believed to be'polychlorodibenzofurans, or polychloro-2-hydroxydiphenylethers, (or both}. We have no current way of quantitating DBF's. While analyzing Catomance Pent esters however, in 1973 (OR 210571-74) for dioxins, I observed that the sampl increased in dioxin content when treated with morpholine and surmized, at that time, that morpholine was causing ring closure of dioxin precursors. I decid to look into this further, as a possible means of quantitating CHDPEls in Pen Five Penta samples were morpholine treated (OR 256745), and after caustic clean-up were GC'd. This gives us a measure of dioxins >4 precursors. The amount of precursors can then be determined by difference from the original dioxin analyses (Al20a cleaned). ` Before Treatment * After Treatroe SAMPLE hepta CDD OCDD UR 212180-1-Plant Penta-Std. Conditions ppm -9 jo ppm 1060 hepta CDD ppm 2624 0 P 62 OR 212180-7-Plant Penta-Amended Cond. W -na 1090 2847 66 OR 211535-Lab Penta-Low Temp. ^rt3 99b 2653 82 KM-261-Plant Penta-Std. Cond. 1980- 2934 86 OR-256338-Lab Penta-(Sulfur + Al Cat.) & UO 870 2151 51 These were the same samples recently analyzed by Applied Scienci. ^ Hepta CL and OCDD levels on the morpholine treated samples have increased dramatically in each case. Hexa CDD was not determined on the treated samples since large amounts of interfering dibenzofurans and phenylethers i^ere not removed prior to morpholine treatment. I also observed that Caustic ( NaOH solution) would likewise, cause cyclizatic o6 the precursors to dioxins (256751). The benzene extracts from the morpholine treated samples were submitted to Applied Science for- low level dioxin analyses (particularily for hexa CDD anc lower chlorinated dioxins). In the meantime,^T developed a method chat allov quantitation of Penta-CDD-rOCDD precursors without the int-erferences in the<he envelope: 9-'V The Penta sample is dissolved in benzene, and chromatogrammed on alumina with excess benzene. All non-phenolics are eluted (this effluent can be GC'd to quantitate original dioxins present). The chlorophenols, which now include pentachlorophenol, tecrachlorophenol, other hydroxy Aromatic and the various dioxin precursors, are released from the aluminia by Me: washing. Morpholine Chlorophenol Dioxin History October 28, 1975 Page 8 is added to the methanol effluent and placed on a steam bath (round bott flask equipped with S n y d e r Colume). The methanol is boiled out while t morpholine causes cyclization of the precursors to dioxins. The solutic is cooled, and acidified to pH^2.0 by addition of 1:1 aqueous Hcl. The released chlorophenols and dioxins are taken up in benzene. The benzene solution is washed twice with aqueous caustic and 3 times with distilled water. Appropriate dilutions in benzene are prepared and subsequently EC The chromatogram is clean of interferences in the Penta CDD and Hexa CDD region allowing ready quantitation of these dioxins (OR256760). A comparison of dioxin values obtained on the morpholine treated benzene extr sent to Applied Scienc4}^7against the values I obtained by the method just de is presented below (OR256774). Concentration (ppm) Unknown Chloro Aromatic Penta CDD Hexa CDD Hepta CDD 212180-1 Control 212180-7 Plant Low Temp. G.W.M. 0.2 0.3 G.W.M. 0.1 0.1 G.W.M. 120 110 S.H.V. G.W.M. 316 2100 320 1800 S 2< 2: 211535 Low Temp. Lab 4 0.4 73 186 1400 2 ' KM-261 Control r n - r 0.3 0.4 50 112 1500 2 256338 Al/S 2 1.5 180 150 1600 2 256304 Al/Te ^ 256386, Reichhold 214234, Mon. distilled - - - - 175 - 1 - - 161 . - 2 - - N.D. - N 130C Batch Sample from Plant > 5 0 ppm Penta CDD (SHV) (Not determined) Indicates not determined G.W.M. analyses are the sum of original dioxins present plus the dioxins generated in morpholine treatment: S.H.V. h exa C D D v a l u e s .rp.nresp.nt or. dioxins formed during morpholine treatment,"and can be considered equivalent to the precursor concentrations in the untreated samples. A ll h e p t a and values are sums of precursors plus original dioxins. What do the analyses tell us? Does the ease of cyclization of the precursor to dioxins have anv significance? 1) First, and most importantly, a similar mechanism of cyclization Could conceivably occur in biological systems, due to the catalytic effect of amides in protein and nucleic acids. The sura of the precursors plus diox in Penta is high enough concentration to account for the degree of CEF Toxic observed.. Attempts to cause cyclization-with egg .albumin, were inconclusive (256763) .[^To v. c f * r`` W j.31 -IV*. -- '*; ^ y/(-w. 2) The values given should not be taken as absolute. Method refiner is needed to determine a number of factors, such as, completeness of cycliza recoveries, etc. Agreement between labs is not good, particularily on hexa values. Confidential-Subject to Protective Order Chlorophenol Dioxin History October 28, 1975 Page 10 14) Chloracne response as measured by Rabbit. Ear test at CMU, also show no clear relation to the precursor concentrations. LITERATURE REVIEW (Aug 75) _ C f **'*(/' Following th discovery of ba.se catalysis of dioxin precursors to dioxins, a thorough review of all dioxin literature, on hand and an up-dated search on new literature, was made. Two questions were in mind. 1) Is anyone studying dioxin precursors as a source of CEF or REC activity in chlorophenols? 2) Has anyone else recognized base catalyzed cylization of these precursors? ----------- ,i w V \' The answer to each of these questions is still "no." The 2nd is evidenced even in the most recent literature (1/75) where caustic is still being used for phenolic extraction in sample preparations. K*'XJ HEXACHLOROBENZENE Presence of hexachlorobenzenes in Penta chlorophenol also came to light in the last year or so. The same benzene extract obtained for dioxin analyses can be GC'd for HCB. Method developed by Applied Science and adapted on my GC, gave the following results on a few selected samples. SAMPLE _________ HEXACHLOROBENZENE IDENTIFICATION______________ OR 212180-1 OR 212180-7 OR 211535 KM-261 OR 256338 OR 214234-Refined ' Reichhold LotNo. 72874 Dow EC-7 Lot No. 09214M Monsanto Australie^ Ba No. 73346026 OR 256399 OR 256304 39.7 31.5 27.7 56.4 13.0 53.4 28.8 106. ppm 15.3 999.6 30.6 Plant Penta - Std. Conditions Plant Penta - Amended Cond. Lab Penta - Low Temp. Plant Penta - Std. Cond. Lab Penta - Al + Sulfur Cat. Plant Penta-Lab Distilled Reichhold's Improved Material Dow's Refined Material Lab - overchlorinated batch Lab, Al/Te cat i/ --Jk e fL a . d Hexachlorobenzene probably comes about through Hcl ether cleavage of dioxin precursors to generate HCB and catechols . Lower chlorinated benzenes are probably also present. There is also indication that Al/S system may suppress HCB formatic to some extent. // ~ < L+' S. H. Vogel L'CK Plant Process Tech. pw Confidential--Subject to Protective Order