Joumalof Occupationaland Envlronmcntal HyghneFor Peer Revlew Only

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Joumal of Occupatlonaland EnvlronmentalHyglene

Letter to the Edltor regardlng "Alrborne exposures assoclated wlth the typlcal use of an aerosol brake cleaner durrns reparr ;:lj;::

Joumal of Oeupdonal & Envlronmental Hyglene

benzeneexposure, toluene, brake cleaner, Industry funded

sclstAft0N€* Manuscripts

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1 ,2 3 66Airborne 4 Letter to the Editor regarding exposuresassociated 5 1ryiththe typical useof an aerosolbrake cleanerduring vehicle 6 7 tepair work" 8 9 Keywords:benzene exposure, 10 toluene,brake cleaner, industry funded 11 12 ExpositionWord Count: 2102 13 14 INTRODUCTION 15 l6 17 The recently published article, Airborne exposures associated with the typical use l8 19 of an aerosol brake cleaner during vehicle repair work,o) is scientifically flawed and 20 21 misleading. ln preface, the authors do not disclose at least two important conflicts of 22 23 24 interest: l) While acknowledging that CRC Industries ("CRC") prepared the "historical" 25 26 Brakleen brake cleaner blends and paid for the field simulation, the authors didnot 27 28 mention that CRC lndustries has been a frequent defendant in benzeneexposure lawsuits 29 30 concerning ("Brakleen"), 3t its Brakleen brake cleaners and 2) lnstead ofdisclosing 32 33 specifically that one of the authors, Dr. Williams, has served as a testifying expert for 34 35 CRC in benzeneexposure lawsuits,e) the authors acknowledge only in general terms that 36 37 she is a testifring expert in benzeneexposure cases. Obviously, these facts matter and 38 39 40 should have been disclosed. The reported benzenecontent ofthe so-called "historical" 41 42 Brakleen(1.6 parts per million), said to havecontained3S% toluene, is improbably low 43 4 and almost certainly in error given the benzenecontents and other relevant properties of 45 6 47 the three commercial grades of toluene that may be purchased in bulk. Importantly, the 48 49 finding that "no detections of benzenewere found" in any sample taken during eight 50 :l ,, i exposure simulations is misleading (and unsurprising) in light of the unrealistically low 52 53 54 benzenecontent of the "historical" Brakleen that was sprayedin the simulations. ln 55 s6 respondingto my letter, the authors should addresssworn testimony given by Dr. 57 58 59 60 http://mc.manuscriptcentral.com/joeh;E-mail:[email protected] Journalof Occupationaland EnvironmentalHygiene-For Peer Review Only Page2 of9

1 2 3 rygilliamsthat nitrationgrade benzene (which has no ASTM specificationfor minimum 4 5. to manufacturebrake cleaner products. i p*ity or maximumbenzene content) is used 7 a NeitherALS Global (C. Amidon, personalcommunication, May 3, 2018)nor CRC 9 1o Industries(A. Selisker,personal communication, May 3, 2018)responded to inf-ormation 11 'l) requestsgennane to the preparationand analysis of "historicalBrakleen." ;; 14 (Spiked" ls Misleading BrakleenBlends t6 17 Brakleenblends B andC in the presentstudy, which CRC ostensiblyprepared by 18 10 A with benzene,had "targeted" benzene contents of )Z "spiking" the "historical" Brakleen 21 zz only 100 parts per million (ppm) and 1,000 ppm, respectively. The article thus createsthe 23 24 false impression that non-chlorinated Brakleen products in the stream of commerce 25 always contained no more than 1,000 ppm benzene(corresponding to an important :i - 28 ;; threshold concentration in benzeneexposure litigation). Becausecommercial brake 30 31 cleaning products general utilize nitration or industrial grade toluene (discussedbelow), - 32 11 their benzenecontents can be more thanl00-fold and l0-fold higher than reported in the 34 35 ;Z article for blends B and C, respectively. 37 38 Toluene and BenzeneContent of ttHistoric" Brakleen 39 The "historical" Brakleenblend A that CRC formulatedreportedly contained3S% Ii 42 ;; toluene(unclear if this is by volumeor weight). As noted,recipes for aerosolbrake 44 45 cleanersgenerally utilize "nitration grade"toluene, which containsas much as2.29%o 46 1l benzene(molar basis;.(r-sl "lndustrial grade" toluene is lesspure and contains as much as 48 49 products asnitration grade are ; . }%benzene(molar basis;.t3'6)In practice,toluene sold 51 i s2 sometimesthe less-pureindustrial grade. For instance,a recentmaterial safety data sheet 53 21 (MSDS) for nitrationgrade toluene communicates an initial boiling point of l09oc 55 56 57 58 59 [email protected] 60 http://mc.manuscriptcentral.com/joeh;E-mail: Page3 of 9 Journalof Occupationaland EnvironmentalHygiene'For Peer Review Only

1 ,2 3 (conespondingto industrialgrade toluene) and a benzenecontent of up to 2.5%(25,000 4 5 6 ppm).o The per unit volumecost of toluenevaries according to its purity grade. The 7 8 purest(99 .9%) grade of toluenethat is commerciallyavailable in bulk is TDI 9 10 Feedstock,(8)which is specifiedto containup to 300ppm benzene.Analytical grade t1 12 (costing per ppm Sincea 13 toluene $125 150ml septumbottle) contains up to 100 benzene. 14 15 20-ouncesize Brakleen aerosol is sold for lessthan five dollars,CRC would of course 16 17 find it costprohibitive to useanalytical grade toluene in its Brakleenproducts. 18 't9 Giventhe recipefor "historical" BrakleenA, CRC would havehad to usetoluene 20 21 22 that contained/ess than I ppm benzeneto accountfor the benzenecontent of BrakleenA, 23 24 asreported in the article. Simplyput, thereis no suchtoluene on the markef- not even 25 26 high pricedanalytical grade toluene sold in pint sizeamber bottles. If the authors 27 28 29 disagree,they can sayso andprovide proof in their response.Curiously, CRC did not 30 31 respondto an email in which I inquiredabout the gradeand properties of tolueneit used 32 33 to prepare"historical" Brakleenblend A. (A. Selisker,personal communication, May 3, 34 35 2018)The authors, 36 who appearto haveblindly acceptedthe analyticalresult 37 38 communicatedto them,offer no documentation(e.g., certificate of analysis,initial 39 40 boiling point,paraffin content)for the toluenegrade CRC usedin formulatingthe 41 42 "historical"Brakleen blend A. Nor do they evencomment on the issue. [n fact, the 43 4 45 authorsdo not saywhether CRC (or an outsidelab it engaged)ever conducted analytical 6 47 testingto measurethe benzenecontent of Brakleenin commerceor of the tolueneused 48 49 by CRC to manufactureit. Certainly,such measurements would havebeen useful to 50 51 52 includein the articlefor comparisonpurposes. I notethat if industrialgrade toluene 53 54 versusnitration grade toluene versus TDI feedstocktoluene versus analytical grade 55 s6 57 58 59 60 http//mc.manuscriptcentral.com/joeh;E-mail: [email protected] Journalof Occupationaland Environmental Hygiene-For Peer Review Only Page4 of9

I 2 3 toluenewere present at38o/o by volumein blendA, onewould expectto seeas much as 4 5 6 the following respectivebenzene concentrations in "historical" BrakleenA (ppm by 7 8 volume):15,200 ppm, 7,600ppm, 114ppm, and38 ppm. Thus,if the 38% of "historical" 9 't0 BrakleenA consistingof toluenewas the analyticalgrade, one would anticipate.up to 24- 11 12 fold morebenzene in blendA thanis reportedin the 13 article. 14 15 While the authorsidentified peer-reviewed NIOSH l50l asthe testused to l6 17 quantiff airborneexposures, the only referencein the articleto the unidentifiedALS 18 l9 Globaltesting method used to determinethe benzenecontents of bulk Brakleenwas that 20 21 22 it involved"gas chtomatographycoupled with a flame ionizationdetector." That is 23 24 analogousto providing a chocolatecake recipe that saysonly that one shouldbake the 25 26 cakein an oven. Basedon the foregoing,I concludeit wasunwise for the authorsto have 27 28 29 blindly reportedthe bulk benzenecontent results communicated to them. 30 31 Air SpeedMeasurements 32 33 Figure5, the authorsgraphically present air speedmeasurements made with a 34 35 36 factory-calibratedthermal anemometer (TSI VelociCalc9535) for ScenarioI (closed 37 38 baysdoors) and Scenario2 (openbay doors). .Thefigure showsthat most air speed 39 40 readingswere lessthan 30 ff/min with frequent"zero"readings and, as expected,the 41 42 43 readingswere higher overall with the bay doorsopen. The authorsseem not to believe 44 45 their own measurementsand classify as "erratic" readingsbelow 30 ff/min. They cite a 46 47 l0-year-oldAmerican Conference of Govemmentallndustrial Hygienists (ACGIH) 48 49 ventilationmanual (reference 34) to supportthe ideathat their anemometerwas 50 { 51 1' 52 unreliableat measuringlow air speeds.However, what the manufacturerTSI saysabout 53 54 the reliability of measurementsmade with its calibratedanemometer is far morerelevant 55 56 57 58 59 60 http://mc.manuscriptcentra l.com/joeh; E-mail: [email protected] Page5 of 9 Journalof Occupationaland Environmental Hygiene'For Peer Review Only

1 2 3 thana generalstatement in an ACGIH manual.Moreover, based on the air speeds 4 5 6 reportedin the cited Wilson,et al. study(reference 26), theauthors likely knew from the 7 8 startthat low air speedswere expected. In turn, if they questionedthe reliability of the 9 t0 TSI instrument,they had ampleoppornrnity to acquirea moreaccurate anemometer. 1l 12 26 not characte thelowmeasured air speeds(well below 30 fVmin) as t3 Reference does irze 14 15 beingindicative of "stagnant"conditions. It wasmisleading for the authorsto havedone 16 17 so withoutjustification (asidefrom admittingthey logged"many of the recordingsas 18 19 zero" becauseof poor performanceof their anemometer). 20 21 s6Typicaltt ttWorst 22 Mischaracterizing Exposures as and Casett 23 24 The title of the article,and the assertionthat the simulationsconesponded to 25 26 27 "tlpical useof an aerosolbrake cleaner" are offered absent independent verification and 28 29 seemsbased on the authors'opinion. To determine"typical use,"one would needto look 30 31 at the variationin aerosolbrake cleaner use by a sizablerandom sample of brake 32 33 job(s); 34 mechanicsperforming the sametype of brake the presentstudy involved exactly 35 36 onebrake mechanic in onelocation. The authorsthemselves allude to a "paucity" of this 37 38 kind of data.Exposure determinants that pertain to "gpical use" are(i) the total volume 39 40 of solventsprayed per wheel period,(ii) of sprayed 41 in a specifiedtime the fraction 42 43 solventthat runsoff into a drip basinor ontothe floor, (iii) the temperatureof the sprayed 4 45 surface(which neednot be the sameas the air temperature),and (iv) the proportionof the 6 47 taskperiod (say, 15 minutes)that the mechanic'sface is closeto the evaporatingsolvent 48 49 50 andthe timing of cleaning. The authors'report data related to item (i) in their Figure3, 5l 52 but reportno datafor items(ii)-(iv). By the timing of cleaning,I refer to whetherthe 53 54 mechanicbegins cleaning a surfaceimmediately after spraying it, or whetherthe 55 56 57 58 59 60 http://mc.manuscriptcentra l.com/joeh; E-mail: jennifer-j-patterson@u iowa.edu Journalof Occupationaland Environmental Hygiene-For Peer Review Only Page6 of9

,1 2 3 mechanicwalks away after sprayingthe surfaceto perform a different task or to let the 4 5 6 solventact on gnme,and thenreturns to the sprayedsurface some minutes later. The 7 8 formertiming would leadto a higherbreathing zone solvent exposure intensity compared 9 10 to the lattertiming. t1 12 The performed 13 authors'assertion that the simulationswere under"worst-case 14 l5 conditionscompared to tlpical work environments"misrepresents the circumstancethat 16 17 "tlpical work environments"vary shopby shop,by work locationwithin a given shop, l8 l9 andby indoor air temperature,which canvary with time of year. The furthera work bay 20 21 22 is locatedfrom an opengarage door, the lower the air speedsin the bay; ina largemulti- 23 24 bay shop,a given work bay easilycan be greaterthan 40 feet from the nearestgarage 25 26 door. During the presentstudy, outdoor air temperaturesranged from 70-90oF, and 27 28 29 indoorair temperaturesranged from 82-96oF. In Phoenix,!rZ,the avgrageoutdoor 30 3l high temperaturein July is l06oF without air cooling,the correspondingaverage indoor - 32 33 high air temperaturewould be at leastl06oF. 34 35 36 Given the "paucity" of relevantexposure data the authorsdiscuss, there is no 37 38 basisfor their misleadingconclusion that exposuresin someof the simulations 39 40 correspondto "worst case"exposures in otherworkplaces (which may numberin the 41 42 hundredsif not thousands)for which there is no information about exposurefactors and 43 44 45 pattemsof productuse. In fact, thereis no basisfor concludingthe simulations 46 47 represented"worst case"exposures even in the locationwhere the simulationswere 48 49 conducted. 50. 51 ,' 52 Misrepresentationabout American Industrial HygieneAssociation 53 54 (AIHA) Accreditation 55 56 57 58 59 60 http://mc.manuscriptcentral.comljoeh;E-mail; [email protected] Page7 of9 Journalof Occupationaland EnvironmentalHygiene'For Peer Review Only

I ,2 3 The authorsfail to revealthat ALS Globalwas not accreditedby the AIHA to 4 5 6 performbulk sampleanalyses for benzene.Unfortunately, their wording left the distinct 7 8 andinaccurate impression that ALS Global'sAIHA accreditation- which only appliedto 9 l0 air sampleanalyses - extendedto bulk sampleanalyses. ALS Globaldid not respondto t1 12 my email(C. Amidon,personal I inquiredabout 13 communication,May 3, 2018)in which 14 15 the detectionlimit andprecision of the test,whether it waspeer reviewed, and whether 16 17 ALS Globalis accreditedby AIHA to performthe test. The ALS Globalwebsite 18 19 indicatesonly that the companyis AlHA-accreditedto analyzeair samples. 20 21 22 CONCLUSION 23 24 ln my opinion,this articleillustrates information bias ("misclassification of 25 . 26 27 exposureestimates") that is prevalentin manyindustry-funded studies.p) Many of these 28 29 studies(including the presentone) report findings favorable to defendantcompanies 30 31 32 fundingthe studies,even if the findingsdo not comportwith real world scientificfacts. 33 34 Importantfalse impressions offered in the currentpaper include, a) historicalCRC 35 36 Brakleenproducts all containedless than 1,000ppm benzene,b) the work simulations 37 38 39 involvedtypical useand worst-case exposure conditions, and c) toluenein Brakleen 40 41 recipecontains less than I ppm benzene.As noted,the authorsshould have specifically 42 43 discloseda) CRC hasbeen a defendantin benzeneexposure lawsuits involving Brakleen 4 45 products,b) Dr. Williams hastestified as an on of 6 expertwitness behalf CRC in Brakleen 47 48 lawsuits,and c) their articlecould be usedby CRC in pendingand futureBrakleen 49 50 lawsuits.To be takenseriously, in their responsethe authorsshould address all the issues 51 52 I raised,including their implicit claim that tolueneused to makecommercial Brakleen 53 54 55 containsless than I ppm benzene.Since the chemicalengineering technology for 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh;E-mail: jennifer-j-patterson6ruiowa.edu Journalof Occupationaland Environmental Hygiene-For Peer Review Only Page8 of9

I 2 1 manufacturingtoluene is essentiallyunchanged for almosta half century,the authors 4 5, t shoulddisclose specific details about any new manufacturingprocess capable of 7 8 producingnitration gradetoluene - or for that matter any toluene- that has lessthan I 9 10 ppm benzene. 't1 12 r: ACKNOWLEDGMENTS 14 15 .t6 As a chemicalengineer, I am a voting memberof threeASTM Committees, 17 t8 includingone (D02) that evaluatesanalyical testingmethods for determiningthe 19 20 propertiesof petrochemicalproducts (including benzene content). I havetestified 21 22 opposite Dr. Williams in numerous benzene ;; exposurecases, including at least one 24 2s involving CRC Industries as a defendant. 26 REFERENCES 28?I 29 30 1. Fries, M, P. Williams, J. Ovesen, and A. Maier: Airborne exposuresassociated 3l 32 with the typical use of an aerosol brake cleaner during vehicle repair work. "/. 33 34 Occup.Environ. Hyg.DOl:10.1080/15459624.2018.1467017. 35 36 37 2. Allsop v.3M Company, Berryman Products, et al.: SuperiorCourt of 38 39 California. Case No. BC-498745 40 4'l 3. Kopstein, M.: Estimating airborne benzeneexposures from air monitoring data 42 43 44 for mineral spirits.J. Occup.Environ. Hyg. 3: l-8, 201l. 45 46 4. Equistar Chemicals LLP: "Material Safety Data Sheet for Toluene Nitration." 47 48 Houston, Texas: Equistar, 2008. 49 :9 : r J. Chevron Phillips Chemical Company: Handling and Storage 5li "Safe of 52 53 Toluene."The Woodlands,Texas: Chevron Phillips ChemicalCompany, 2006. 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh;E-mail: [email protected] Page9 of9 JoumalofOccupatlonal and Envlrcnmental llyglenFFor Peer Revlew Only

I ,'2 3 6. Equister Chemicals, LLP: "Material SafetyData Sheetfor TolueneCommercial 4 5 6 Grade." Houston,Texas: Equistar, 2003. 7 8 7. CITGO Petroleum Corporation:'Material SafetyData Sheetfor Toluene 9 l0 - Meeting ASTM D-841 Nination GradeSpecifications." L€monl Illinois" CITGO t1 12 13 PeholeumCorporation, 201 8. l4 t5 8. ASTM Internetional: Sandard Specificationfor Toluenefor Toluene t6 17 Diisocyanate(TDI) Feedstock(D5606-2006). West Conshocken,PA: ASTM, l8 l9 2006. 20 21 22 9. Micheels, D.: Doubt is theirproducfi how industry's assaulton sciencethreatens 23 24 your health. New York Oxford Univenity press,2008. 25 26 27 28 29 30 3l 32 33 v 35 36 37 38 39 4 41 42 43 4 45 6 47 I 49 50 51 t 52i 53 v 55 56 57 58 59 60 http//mc.manuscriptcentnl.com/joeh;E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only

Journal of Occupational and Environmental Hygiene

Letter to the Editor regarding "Airborne exposures associated with the typical use of an aerosol brake cleaner during vehicle repair work"

Journal: Journal of Occupational & Environmental Hygiene

Manuscript ID JOEH-18-0117

Manuscript Type: Letter to the Editor

Keyword: benzene exposure, toluene, brake cleaner, industry funded

http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 1 of 17 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 INTRODUCTION 4 5 6 On May 15, 2018, I submitted a letter to the editor of JOEH (“first letter”) 7 8 concerning an “accepted” manuscript entitled Airborne exposures associated 9 10 with the typical use of an aerosol brake cleaner during vehicle repair work. For 11 12 reasons discussed below, I withdrew my first letter and am responding to the 13 14 (1) 15 revised manuscript that was recently published. 16 17 My first letter asserted that the accepted manuscript was scientifically 18 19 flawed and misleading. In it, I identified two undisclosed conflicts of interest: 1) 20 21 22 CRC Industries has been a defendant in benzene exposure lawsuits concerning 23 24 its Brakleen brake cleaners (“Brakleen”), and 2) one of the authors, Dr. Williams, 25 26 has testified for CRC Industries regarding the benzene content of Brakleen brake 27 28 29 cleaners and benzene exposures arising from their uses.” The JOEH editor (R. 30 31 Anthony, personal communication June 15, 2018) informed me that the authors 32 33 had been provided my “first letter.” In that email she also sent an updated “final” 34 35 manuscript” (i.e., the published version). The latter has at least seven substantive 36 37 38 revisions, with all but one inarguably in response to my first letter. For the 39 40 reasons presented below, I believe the “final” manuscript remains scientifically 41 42 flawed and misleading, and hence this second letter. 43 44 45 CONFLICTS OF INTEREST 46 47 As they conducted their review of the manuscript, JOEH peer reviewers 48 49 were unaware of important and undisclosed conflicts of interest. 1) The “final” 50 51 52 manuscript does not disclose that one of the authors (AM) has authored 53 54 numerous published articles in which financial sponsorship came from chemical 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 2 of 17

1 2 3 manufacturers and chemical trade associations, including the American 4 5 6 Chemistry Council and the American Petroleum Institute. 2) The authors 7 8 acknowledge that CRC “funded the field exposure study.” However, their 9 10 assurance that “no financial support or oversight was provided for the 11 12 preparation of this manuscript” is inaccurate; namely, the article essentially 13 14 15 mirrors an unpublished report, Workplace/Simulation Study of Benzene and Total 16 17 Hydrocarbon (THC) Exposures Associated with an Aerosol Brake Cleaner, dated 18 19 January 20, 2017 (discussed later in this letter) that was “prepared for CRC 20 21 22 Industries” and “led by” AM and PDRW. By “prepared for”, I infer that CRC paid 23 24 for it. 3) The authors do not disclose that the 2017 CRC-funded study has been 25 26 regularly utilized by CRC and PDRW in benzene exposure lawsuits (it is 27 28 29 therefore referred to in this letter as the “litigation study”). 4) The “accepted” 30 31 manuscript withheld the fact that Dr. Williams has served as an expert witness for 32 33 CRC. The “final” manuscript only somewhat corrects that oversight. It falls short 34 35 of disclosing that PDRW has been an expert witness for CRC on at least eight 36 37 38 occasions since 2012. Billing records in just one case reveal her charges for time 39 40 spent in excess of $40,000 - incurred in just two months. 41 42 BENZENE AND OTHER CHEMICALS FOUND IN TOLUENE 43 44 45 The refinery process for manufacturing toluene consists of three steps, 1) 46 47 catalytic reforming, 2) extractive distillation to remove aliphatic impurities, and 3) 48 49 several distillations to separate toluene from benzene and other aromatics.(2) 50 51 (3) 52 Since catalytic reforming has been widely-used since the 1950s, and the 53 54 process just described has been the same for decades, it is unsurprising that the 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 3 of 17 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 benzene content of toluene has remained the same over that same period.(4) 4 5 6 Nevertheless, the authors revised the accepted manuscript by implying (without 7 8 citing a reference) that comparable grades of toluene contained more benzene in 9 10 the past than now. 11 12 Toluene comprised 38.3% of Brakleen Blend A. The grade and 13 14 15 provenance of the toluene CRC used is not discussed in the article. Based upon 16 17 the 1.4 ppm benzene in Blend A that ALS Global measured, Blend A toluene 18 19 contained only 3.68 ppm benzene. Such an ultrapure toluene (not made in a 20 21 22 refinery process) requires complex and expensive treatment that incorporates the 23 24 drying of purchased toluene with an active reagent, and then distilling it under an 25 26 inert atmosphere.(5) Sigma Aldrich sells an ultrapure toluene(6) (costing more than 27 28 29 $100 per 150 ml septum) that is guaranteed to be more than 99.9% pure and to 30 31 contain less than 100 ppm benzene - probably a lot less. One expects negligible 32 33 concentrations of xylene isomers, ethyl benzene, and nonaromatic hydrocarbons 34 35 to be present in such an ultrapure toluene. 36 37 38 Consensus ASTM specifications exist for the three commercial grades of 39 40 toluene, (a) industrial(7), (b) nitration(8), and (c) TDI feedstock.(9) TDI feedstock is 41 42 the only toluene grade having specified maximum benzene content (300 ppm). 43 44 45 ASTM specifications for the nitration and industrial grades also place no 46 47 concentration limits on xylene isomers and ethyl benzene. To be discussed is the 48 49 fact that toluene sold for solvent use (nitration and industrial grades) contains 50 51 52 significant concentrations of benzene, xylene isomers (ortho, meta, para), ethyl 53 54 benzene, and nonaromatic hydrocarbons such as heptane isomers. Table 1 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 4 of 17

1 2 3 summarizes the benzene content of different grades of toluene. Variability in 4 5 6 benzene levels occurs because toluene is a commodity product that is frequently 7 8 a mixture comprised of toluene coming from different manufacturers and 9 10 refineries.(4) 11 12 CRC uses nitration grade toluene in its Brakleen products.(10) However, 13 14 15 based on three factors (and assuming the ALS Global measurements are 16 17 accurate) I conclude that nitration grade toluene was not used to formulate 18 19 Brakleen A. First, the 3.68 ppm benzene content of the toluene used in Brakleen 20 21 22 A is up to four orders of magnitude below the benzene content of nitration grade 23 24 toluene. In fact, Blend A toluene contains less than 0.2% of that found in the 25 26 unspecified grade of toluene sold by Total Petrochemicals in 2013 (see Table 1). 27 28 29 Second, ALS Global did not measure any nonaromatic hydrocarbons in Brakleen 30 31 A, a result that is inconsistent with the fact that nitration grade toluene is known 32 33 to contain significant levels of nonaromatic hydrocarbons.(8, 11) Third, 34 35 Supplemental Table 1 reports only the amount of xylene added by CRC to 36 37 38 achieve the targeted xylene concentration in Blend A. The results should have 39 40 also reflected xylene isomers and ethyl benzene known to be present as 41 42 important contaminants in nitration grade toluene. For example, the 43 44 45 concentration of C8 aromatics (combined xylene isomers and ethyl benzene) in 46 47 nitration grade toluene can easily exceed 10,000 ppm.(11,12) 48 49 CERTIFICATES OF ANALYSIS (COAs) 50 51 52 My first letter pointed out, “The authors, who appear to have blindly 53 54 accepted the analytical result communicated to them, offer no documentation 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 5 of 17 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 (e.g., certificate of analysis, initial boiling point, paraffin content) for the toluene 4 5 6 grade used by CRC in formulating the “historical” Brakleen blend A.” In response, 7 8 the authors now state that COAs they reviewed “are consistent” with the benzene 9 10 contents in Supplemental Table 1. Since the COAs were not cited, it is obvious 11 12 that they were neither seen nor considered by JOEH peer reviewers. The CRC 13 14 15 litigation study does not discuss COAs, or even acknowledge the need 16 17 demonstrate that reported benzene content for Brakleen blends are accurate and 18 19 representative of Brakleen non-chlorinated brake cleaners placed in the stream 20 21 22 of commerce. 23 24 It is widely understood that supplier COAs do not necessarily provide 25 26 robust and accurate information concerning the composition of raw materials. It 27 28 29 is for that reason that scientists recognize the importance of a) independent, third 30 31 party analytical testing of purchased raw materials, and b) verifying the accuracy 32 33 of COAs.(13-15) For instance, in discussing the sampling and testing of raw 34 35 materials, the US Food and Drug Administration (FDA) writes, “As a minimum, a 36 37 38 complete analysis should be performed at appropriate intervals and compared 39 40 with COAs. Reliability of COAs should be checked at regular intervals.”(14) 41 42 Similarly, a well-known analytical chemistry textbook recommends that analytical 43 44 (15) 45 methods referred to in COAs be “critically reviewed.” For reasons explained in 46 47 the next paragraph, it is quite clear that neither the authors nor CRC can verify 48 49 the accuracy of benzene contents communicated in toluene COAs utilized by 50 51 52 CRC after 2001. 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 6 of 17

1 2 3 The above admonitions are highly relevant in the present instance 4 5 6 because it has been established that errors occur in the reporting of benzene 7 8 contents in toluene COAs. For example, over a period of many years, a major 9 10 toluene producer/supplier admitted furnishing COAs in which ASTM D2306(16) 11 12 was listed as the test used to measure the benzene content of toluene reported 13 14 (17) 15 in COAs. However, D2306 measures the distribution of ethyl benzene and the 16 17 three xylene isomers present in xylene mixtures. Obviously, since D2306 has 18 19 nothing to do with benzene or toluene, all the benzene contents reported in the 20 21 22 toluene COAs issued during the multiyear period were erroneous. As an expert 23 24 witness for CRC, PDRW prepared summaries of approximately 400 COAs for 25 26 toluene CRC used in its Brakleen products - including at least 52 from the major 27 28 29 supplier that used the wrong ASTM analytical testing method, ASTM D2306. 30 31 “Hundreds” of COAs were also available in late 2014 for toluene and other 32 33 ingredients CRC used in Brakleen products.(20) 34 35 As noted, there is no indication that JOEH peer reviewers considered the 36 37 38 relevant COAs in their evaluations - or even saw them. Since the authors relied 39 40 on them, the COAs in question - not the summaries - should be produced to 41 42 JOEH. While I had hoped to discuss the COAs in this letter to the editor, I 43 44 45 received no responses to my requests that they be provided to me. (A. Selisker, 46 47 personal communication, May 3, 2018) (V. Henry, personal communication, June 48 49 19, 2018) 50 51 52 MISLEADING “SPIKED” BRAKLEEN BLENDS 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 7 of 17 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 Brakleen blends B and C were obtained by “spiking” Blend A with pure 4 5 6 benzene to achieve “targeted” benzene contents of 100 ppm and 1,000 ppm, 7 8 respectively. The article thus creates the impression that non-chlorinated 9 10 Brakleen products in the stream of commerce never contained more than 1,000 11 12 ppm benzene (an important threshold in benzene exposure litigation). Given the 13 14 15 proportion of toluene in Brakleen Blend A, the authors are also creating the 16 17 impression that nitration grade toluene cannot contain more than 2,600 ppm 18 19 benzene, which Table 1 shows is not the case. In order to know how much 20 21 22 benzene and toluene to add to the blends to achieve the targeted compositions, 23 24 CRC would first need to know that the toluene used contained de minimus levels 25 26 of xylene isomers, ethyl benzene, benzene, and nonaromatic hydrocarbons. 27 28 29 ANALYTICAL RESULTS 30 31 It would have been quite easy and straightforward to accurately determine 32 33 the benzene content of the Brakleen blends. First, the benzene content of the 34 35 toluene used could have been accurately measured using ASTM International 36 37 (21) 38 D2360, which has a benzene detection limit of 10 ppm. ASTM testing methods 39 40 are consensus gold standards(4) that are used to referee disputes.(15) Then, the 41 42 benzene content of the blend would have been easily calculable by multiplying 43 44 45 the ASTM 2360 result by the fraction of the blend that was made up of toluene. 46 47 Instead of this approach, the “final” article reports that NIOSH NMAM 1501(22) (a 48 49 peer-reviewed method for air samples only) was used to analyze the Brakleen 50 51 ) 52 liquid blends. Curiously, NMAM 1501 is not mentioned in relevant analytical 53 54 testing records forwarded to me by JOEH. (JOEH: personal communication, July 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 8 of 17

1 2 3 3, 2018) Rather, the records reveal that an ALS in house method (“IH-001”) was 4 5 6 used to analyze Brakleen blends. I have not seen the IH-001 standard operating 7 8 procedure and am not prepared to comment on it in this letter. The CRC litigation 9 10 study does not identify a specific test; as with the “accepted” manuscript it says 11 12 GC/FID was utilized. 13 14 15 The article does not explain a few reporting errors regarding the analysis 16 17 of bulk Brakleen blends. Supplemental Table 1, which reports the measured 18 19 composition of bulk Brakleen blends and aerosols, does not account for 58,000 20 21 22 ppm and 28,500 ppm of other chemicals present in the A and C blends, 23 24 respectively. For the B Blend, the measurements add up to 105.2%. Those errors 25 26 are significant and must be explained. Additionally, the “final” manuscript does 27 28 29 identify the chemicals that comprise “THC” in Supplemental Tables 2, 3, and 4. If 30 31 only hydrocarbons are included, then the tabulated values are much too high, 32 33 given that the only hydrocarbons said to be present in the Brakleen blends are 34 35 toluene and small amounts of benzene and xylene. On the other hand, the 36 37 38 tabulated values are too low if they include airborne acetone and/or methanol, 39 40 given the physico-chemical properties of both. In the section that concerns the 41 42 CRC litigation study, reference is made to analytical testing concerns that were 43 44 45 communicated to the authors, and that were not carried through to the “final” 46 47 manuscript. 48 49 “TYPICAL” AND “WORST CASE” MISCHARACTERIZATIONS 50 51 52 The assertions that the simulations corresponded to “typical use of an 53 54 aerosol brake cleaner,” and that some high-temperature/low-air-speed conditions 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 9 of 17 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 encountered represented “worst-case workplace conditions,” are offered absent 4 5 6 independent verification and seem based on the authors’ opinion. The fact is, the 7 8 authors studied one mechanic in one facility during eight uses of a brake cleaner. 9 10 I note that “typical” is missing in the title to the CRC litigation study. 11 12 To determine “typical use,” one would need to look at the variation in 13 14 15 aerosol brake cleaner use by a sizable random sample of mechanics performing 16 17 the same type of brake job(s). Exposure determinants that pertain to “typical 18 19 use” are a) the total volume of solvent sprayed per wheel in a specified time 20 21 22 period, b) the fraction of sprayed solvent that runs off into a drip basin or onto the 23 24 floor, c) the temperature of the sprayed surface and aerosol product (which need 25 26 not be the same as the air temperature), and d) the proportion of the task period 27 28 29 (say, 15 minutes) that the mechanic’s face is close to the evaporating solvent 30 31 and the timing of cleaning. The authors’ report data related to item (a) in their 32 33 Figure 3, but report no data for items (b)-(d). By the timing of cleaning, I refer to 34 35 whether the mechanic begins cleaning a surface immediately after spraying it, or 36 37 38 whether the mechanic walks away after spraying the surface to perform a 39 40 different task or to let the solvent act on grime, and then returns to the sprayed 41 42 surface some minutes later. The former timing would lead to a higher breathing 43 44 45 zone solvent exposure intensity compared to the latter timing. 46 47 The authors’ assertion that some simulations were performed under 48 49 “worst-case workplace conditions” is also unfounded. To start with, the authors 50 51 52 do not consider environmental conditions and patterns of use encountered by 53 54 mechanics in countless other workplaces. During the present study, outdoor air 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 10 of 17

1 2 3 temperatures ranged from 70 to 90 degrees F, and indoor air temperatures 4 5 6 ranged from 82 to 96 degrees F. In Phoenix, AZ, the average outdoor high 7 8 temperature in July is 106 degrees F; without air cooling, the corresponding 9 10 average indoor high air temperature would be at least 106 degrees F. With 11 12 regard to air speeds, the speeds depicted in Figure 5(a) appear consistent with 13 14 15 the findings of Wilson, et al., (cited as a reference) who reported that “the GM air 16 17 speed was 3 and 4 m/min (10 to 12 ft/min) in rear and middle work areas” of ten 18 19 vehicle repair shops. The majority of work stations need not be located at the 20 21 22 fronts of shops near open garage doors where air speeds are higher. 23 (18) 24 Interestingly, the testimony of a CRC Vice President in a lawsuit seems 25 26 to refute the “typical” and “worst case” exposure characterizations in the article. 27 28 29 The testimony was that CRC had never conducted benzene exposure monitoring 30 31 tests during use of its Brakleen product because: “We wouldn’t be able to 32 33 properly reproduce every possible scenario that a mechanic would encounter. 34 35 There’s so many environmental conditions that need to be measured in any 36 37 38 specific test that if we were to test in one area and come up with the results, they 39 40 would probably not be meaningful to the next person in another scenario.” 41 42 CRC LITIGATION STUDY 43 44 45 There are noteworthy differences between the CRC litigation study and 46 47 the “final” manuscript: 1) It has a title different than the article and does not 48 49 contain the word “typical.” 2) Table 1 in the study provides the chemical 50 51 52 composition for Brakleen product 05088. I conclude that xylene was present in 53 54 the commercial product because it was a contaminant in the toluene at 5,222 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 11 of 17 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 ppm, consistent with the earlier discussion about xylene levels in nitration grade 4 5 6 toluene. 3) The study reports that ALS Global used GC/FID to analyze bulk 7 8 Brakleen, the same approach the “accepted” manuscript discusses. It makes no 9 10 mention that NIOSH NMAM 1501 was used for the bulk liquid analyses. As 11 12 noted, lab records show reveal that in-house method IH-001 test (not offered in 13 14 15 the ALS Catalog) was used. 4) The litigation study mentions the ALS Laboratory 16 17 director raised questions about the identity and concentration of chemicals 18 19 comprising the THC results. Reference to this unresolved problem was omitted 20 21 22 from the “final” manuscript. 5) The “final” manuscript does not repeat the 23 24 admonition from the same ALS director that ”methanol and acetone (two of the 25 26 primary constituents of the Brakleen formulations) are not designated analytes 27 28 29 per the NIOSH 1501 method.” As discussed earlier, methanol and acetone 30 31 present potential analytical interferences to NMAM 1501. 6) The “final” 32 33 manuscript does not communicate the fact that, because of equipment 34 35 malfunctions, “the air exchange rate in the garage was not measured during the 36 37 38 study.” I provided the JOEH editor with documents discussed herein that pertain 39 40 to the CRC litigation study. (Dr. R. Anthony, personal communication, July 5, 41 42 2018) 43 44 45 CONCLUSION 46 47 This article communicates inaccurate and misleading results. Based on the many 48 49 issues raised in this letter, along with the JOEH view that “Short Reports” are 50 51 52 articles having “limited generalizability” (JOEH, personal communication, June 53 54 15, 2018) the authors should not have offered their opinion that the results are 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 12 of 17

1 2 3 representative of typical and worst case exposures a mechanic would encounter 4 5 6 while using Brakleen products. I recommend an erratum deleting “typical” from 7 8 the title, and deleting “typical” and “worst case” from the body of the article. I also 9 10 recommend that in a supplemental on-line file, the authors make available to 11 12 JOEH readers the unedited toluene Certificates of Analysis (not summaries) 13 14 15 upon which they relied. Finally, I recommend that, in the future, JOEH should 16 17 require authors to provide enough information to allow reviewers to evaluate the 18 19 accuracy of analytical testing records. 20 21 22 ACKNOWLEDGEMENTS 23 24 I am a voting member of three ASTM Committees, including one (D02) that 25 26 evaluates analytical methods for determining the properties of petrochemical 27 28 29 products (including benzene content). I have testified opposite Dr. Williams in 30 31 numerous benzene exposure cases, including at least one involving CRC 32 33 Industries as a defendant. I did not serve as an expert witness in any matter in 34 35 which the CRC litigation study was relevant. I have never received compensation 36 37 38 for preparing articles published in peer-reviewed journals. 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 13 of 17 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 REFERENCES 4 5 6 1. Fries, M., P. Williams, J. Ovesen, and A. Maier: Airborne exposures associated 7 8 with the typical use of an aerosol brake cleaner during vehicle repair work. J. 9 10 Occup. Environ. Hyg. 2018. 15, 7: 531-540 11 12 2. United States Environmental Protection Agency. Locating and estimating air 13 14 15 emissions from sources of toluene. EPA-454/R-93-047. March 1994. 16 17 3. Peavy, C.C. The importance of platinum in petroleum refining. Platinum Metals 18 19 Rev. Volume 2 (2), 48-52. 1958 20 21 22 4. Whitlock, W. Deposition testimony, Whitehead et al. v. Baxter Healthcare et al. 23 24 US District Court for the Eastern District of Missouri, Case No. 4:08-cv-421, at 25 26 Pages 9, 45 and 80. March 16, 2010. 27 28 29 5. Kadish, K.M., M. Xihai, and J.E. Anderson. Recommended methods for the 30 31 purification of solvents and tests for impurities benzene and toluene. Pure & Appl. 32 33 Chem., Volume 61 (10) 1823-1828. 1989 34 35 6. Sigma-Aldrich. Toluene dried. Product 1.08326. 36 37 38 https://www.sigmaaldrich.com/catalog/product/mm/108326?lang=en®ion=US. 39 40 (Last accessed July 2, 2018) 41 42 7. ASTM International. Designation: D362-84. Standard Specification for 43 44 45 Industrial Grade Toluene. Philadelphia, PA. 1984 46 47 8. ASTM International. Designation: D841-01 (Reapproved 2006). Standard 48 49 Specification for Nitration-Grade Toluene. West Conshohocken, PA. 50 51 52 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 14 of 17

1 2 3 9. ASTM International. Designation: D5606-01 (Reapproved 2006). Standard 4 5 6 Specification for Toluene Diisocyanate (TDI) Feedstock. West Conshohocken, 7 8 PA. 9 10 10. Williams, PRD. Deposition testimony, Volume II. Allsop v. CRC Industries, Inc. 11 12 et al. Superior Court, Los Angeles County, Case No. BC-498745, at Page 297. 13 14 15 January 7, 2015 16 17 11. Chevron Phillips Chemical Company: “Safe Handling and Storage of Toluene.” 18 19 The Woodlands, Texas: Chevron Phillips Chemical Company, 2006 20 21 22 12. Equistar Chemicals LLP: “Material Safety Data Sheet for Toluene Nitration.” 23 24 Houston, Texas: Equistar, 2008 25 26 13. California Military Environmental Coordination Committee. Best practices 27 28 29 for the detection and deterrence of lab fraud. Version 1.0. March 1997 30 31 14. United States Food and Drug Administration. Manufacturing practice 32 33 guidance for active pharmaceutical ingredients. August 2001. 34 35 https://www.fda.gov/ICECI/ComplianceManuals/CompliancePolicyGuidanceMan 36 37 38 ual/ucm200364.htm (Last accessed July 2, 2018) 39 40 15. Grob, R.L. and E.F. Barry. Modern Practice of Gas Chromatography. 4th 41 42 Edition. ISBN 0-471-22983-0. John Wiley and Sons. 2004 43 44 45 16. ASTM D 2306-00. Standard Test Method for C8 Hydrocarbon Analysis by Gas 46 47 Chromatography. West Conshocken, PA. 48 49 17. Perdue, E. Deposition testimony. Scearce v. Sherwin Williams et al. State of 50 51 52 North Carolina Superior Court Division. Case No. 008CVS420 at Page 61. March 53 54 15, 2011. 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 15 of 17 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 18. Selisker, A. Deposition testimony, Ewen et al v. Radiator Specialty et al. Superior 4 5 6 Court of the State of Washington, Case No. 09-2-06135-7, at pages 66 and 88. 7 8 May 18, 2010 9 10 19. Williams, PRD. Deposition testimony, Volume I. Allsop v. CRC Industries, Inc. 11 12 et al. Superior Court, Los Angeles County, Case No. BC-498745, at Page 92. 13 14 15 December 19, 2014 16 17 20. Williams, PRD. Expert report of Pamela RD Williams, ScD., Allsop v. 3M et al. 18 19 at Page 69. December 17, 2014 20 21 22 21. ASTM International. Designation: D2360-04a. Standard Test Method for Trace 23 24 Impurities in Monocyclic Aromatic Hydrocarbons by Gas Chromatography. West 25 26 Conshohocken, PA. 27 28 29 22. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition., Method 30 31 Hydrocarbons, Aromatic: Method 1501March 15, 2003 32 33 23. Chevron Phillips Chemical Company: Material Safety Data Sheet (#3476) for 34 35 Toluene (Reference Fuel) . The Woodlands, TX. Revision Date August 15, 2002. 36 37 38 24. Kopstein, M. Estimating airborne benzene exposures from air monitoring data for 39 40 mineral spirits. J. Occup. Environ. Hyg. 2011. 3: 1-8 41 42 25. Total Petrochemicals and Refining: Material Safety Data Sheet for Toluene. 43 44 45 Houston, TX. March 7, 2013. 46 47 26. Total Petrochemicals and Refining: Product Summary Toluene. May 2017 48 49 27. Chevron Phillips Chemical Company. Material Safety Data Sheet for Toluene 50 51 52 (Commercial Grade). The Woodlands, Texas. July 21, 2003 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 16 of 17

1 2 3 28. Equistar Chemicals, LLP: “Material Safety Data Sheet for Toluene Commercial 4 5 6 Grade.” Houston, Texas: Equistar, 2003. 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 17 of 17 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 Table 1: Benzene Content of Different Toluene Grades 4 5 6 TYPE OF TOLUENE YEAR BENZENE CONTENT PPM w/w 7 unless otherwise stated 8 Blend A Toluene (Note 1) 2018 3.68 9 Ultra Pure(6) (Note 2) 2018 Up to 100 10 Hillman (Note 3) 1978 Possibly greater than 1,000 11 (23) 12 Reference Grade (Note 4) 2002 Up to 1,000 ppm (11) 13 Nitration 2006 20,000 14 Nitration(12) 2008 20,000 (up to 50,000) 15 Nitration(24) 2011 Up to 2.29% (molar) 16 Unspecified(25) 2013 2,000 17 (26) 18 Unspecified (Note 5) 2017 Greater than 1,000 (27) 19 Commercial (Note 6) 2000 Up to 25,000 20 Commercial(28) (Note 6) 2014 Up to 15,000 21 22 Note 1: Article does not provide grade and purity 23 Note 2: Purity guaranteed to be higher than 99.9%; $125 per 150 ml septum 24 25 Note 3: Reference #2 in the Article refers to toluene as “benzene critical” solvent 26 Note 4: Purity higher than 99.9% (per ASTM TDI Feedstock Toluene); MSDS has 27 benzene carcinogenicity warning 28 Note 5: Toluene is Category 1A carcinogen because it contains more than 1,000 29 ppm benzene 30 Note 6: Does not specify if nitration or industrial 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only

Journal of Occupational and Environmental Hygiene

Letter to the Editor regarding "Airborne exposures associated with the typical use of an aerosol brake cleaner during vehicle repair work"

Journal: Journal of Occupational & Environmental Hygiene

Manuscript ID JOEH-18-0117.R2

Manuscript Type: Letter to the Editor

benzene exposure, toluene, brake cleaner, industry funded, analytical Keyword: testing

http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 1 of 9 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 INTRODUCTION 4 5 6 The purpose of this letter is to discuss scientific errors, inaccurate 7 8 statements, and undisclosed conflicts of interest in the Short Report (SR), 9 10 Airborne exposures associated with the typical use of an aerosol brake cleaner 11 12 during vehicle repair work. (1) 13 14 15 UNDISCLOSED CONFLICTS OF INTEREST 16 17 1) The same authors conducted the CRC-funded simulation in 2016, two years 18 19 before publication of the SR. The findings and simulation results were 20 21 22 memorialized in an unpublished report (available as a supplement to this letter). 23 24 2) The unpublished report is utilized regularly in benzene exposures lawsuits, 25 26 with one of the authors (PDRW) relying on it in as a CRC expert witness in at 27 28 29 least two benzene exposure lawsuits, 3) The SR draws extensively from the 30 31 unpublished litigation report without referring to it, and 4) One of the authors (AM) 32 33 is the author of numerous published articles funded by chemical manufacturers 34 35 and chemical trade associations, including the American Chemistry Council and 36 37 38 the American Petroleum Institute. 39 40 BENZENE CONTENT OF TOLUENE 41 42 Consensus ASTM specifications exist for the three commercial grades of 43 44 (2) (3) (4) 45 toluene, (a) industrial , (b) nitration , and (c) TDI feedstock. TDI feedstock is 46 47 the only toluene grade having specified maximum benzene content (300 ppm) 48 49 and minimum purity (99.9% toluene). Toluene sold for solvent use (nitration and 50 51 52 industrial grades) also contains benzene, xylene isomers (ortho, meta, para), 53 54 ethyl benzene, water, and nonaromatic hydrocarbon impurities such as heptane 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 2 of 9

1 2 3 isomers. Variability in composition occurs because toluene is a commodity 4 5 6 product that is frequently a mixture comprised of toluene from different 7 (5) 8 manufacturers and refineries. The refinery process for manufacturing toluene 9 10 consists of three steps, 1) catalytic reforming (widely used since the 1960s(6)), 2) 11 12 extractive distillation to remove aliphatic impurities, and 3) several distillations to 13 14 (7) 15 separate toluene from benzene and other aromatics. Since the process just 16 17 described has been the same for decades, it is unsurprising that the benzene 18 19 content of the different grades of toluene has remained the same over that same 20 21 (5) 22 period. Table 1 summarizes the benzene content toluene prior to 2013. ASTM 23 24 specifications for nitration grade toluene became more stringent in 2013 25 26 (minimum purity of 98.8%; but no limit on benzene content).(8) 27 28 29 Brakleen Blend A contained 38.3% toluene. Since the measured benzene 30 31 content of Blend A was reportedly 1.4 ppm, the toluene that CRC used to 32 33 prepare it contained only 3.66 ppm benzene (1.4 /0.383). This benzene content 34 35 is to be viewed with skepticism because, with the exception of ultrapure toluene 36 37 38 used in laboratory applications, it is orders of magnitude below the benzene 39 40 levels in Table 1 (spanning 1978 to 2017). Each order of magnitude is a factor of 41 42 ten. 43 44 45 “SPIKED” BRAKLEEN BLENDS 46 47 CRC prepared Brakleen blends B and C by “spiking” Blend A with pure 48 49 benzene to achieve “targeted” benzene contents of 100 ppm and 1,000 ppm, 50 51 52 respectively. This creates the impressions that a) non-chlorinated Brakleen 53 54 products could not contain more than 1,000 ppm benzene (an important 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 3 of 9 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 threshold in benzene exposure litigation), and b) toluene cannot contain more 4 5 6 than 2,600 ppm benzene (1,000/0.383), which Table 1 shows is not the case. 7 8 The grade and benzene content of toluene that CRC used to prepare Blend A 9 10 was not mentioned in the Short Report. Without first testing for the benzene 11 12 content of Blend A toluene, CRC could not have known the volume of benzene 13 14 15 necessary to achieve the “spiked” benzene contents - unless the toluene used 16 17 contained almost no benzene (consistent with an ultrapure toluene sold for 18 19 laboratory applications). CRC does not test to determine the benzene content of 20 21 (9) 22 incoming toluene. 23 24 RELIABLE WAY TO DETERMINE BENZENE CONTENT OF CRC BLENDS 25 26 The benzene content of the CRC Brakleen blends could have been 27 28 29 reliably determined by using a widely accepted standard method that has 30 31 undergone peer review. First, the benzene content of the toluene used in the 32 33 blends could have been accurately measured using ASTM International D2360, 34 35 which has a benzene detection limit of 10 ppm.(10) The benzene content of Blend 36 37 38 A is calculable by multiplying the ASTM 2360 result by the fraction of the blend 39 40 that was made up of toluene. ASTM testing methods are consensus standards 41 42 that are used to referee disputes.(11) As discussed below, the accuracy and 43 44 45 reliability of the reported benzene contents of CRC blends are very much in 46 47 question. 48 49 ANALYTICAL TESTING OF BULK LIQUID BRAKLEEN BLENDS 50 51 52 There appears to be a difference of opinion between the authors and ALS 53 54 Global regarding the analytical testing method used to measure the benzene 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 4 of 9

1 2 3 content of bulk Brakleen blends. According to the SR, ALS analyzed the liquid 4 5 (12) 6 blends by NMAM 1501 with an Agilent DB-MTBE capillary column. According 7 8 to ALS, however, it used testing method “Gas-Chromatography-Rinsate IH-001” 9 10 (not offered in the ALS Catalog of services) - not NMAM1501 as stated by the 11 12 authors. “IH” can denote an in-house test. Finally, the aforementioned 13 14 15 unpublished report (available as a supplement to this letter) states the Brakleen 16 17 blends were analyzed by gas chromatography with a flame ionization detector 18 19 (no specific analytical testing method was identified). The scientific merit of the 20 21 22 reported benzene contents cannot be established without identification of the 23 24 actual analytical testing method and its performance properties (e.g., detection 25 26 limit, precision, reporting limits, interferences). The article does not say if the “IH” 27 28 29 test has been published or peer-reviewed, or if it represents a modification of 30 31 NMAM 1501. In general, it is a good idea for authors to communicate details 32 33 about unpublished analytical methods, as well as about standard methods that 34 35 have been modified, so reviewers and readers can better understand the method 36 37 38 and evaluate the results. It is unclear why the authors selected a laboratory that 39 40 they say is accredited to perform NMAM 1501 on air samples, while at the same 41 42 time acknowledging that the lab lacks accreditation for determining the benzene 43 44 45 content of bulk liquids. 46 47 There are legitimate concerns if NMAM 1501 was used to analyze liquid 48 49 samples. To start with, the capillary column identified by the authors differs 50 51 52 markedly from the one specified in NMAM documentation (fused silica PEG 53 54 capillary column or equivalent having polar properties). The column discussed in 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 5 of 9 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 the SR, Agilent DB-MTBE, is a non-polar column for determining the 4 5 6 concentration of MTBE in soil and water. Secondly, NMAM 1501 is for 7 8 determining the concentration of aromatic hydrocarbons in air samples. It is not 9 10 intended for liquids. Lastly, ketones and alcohol (which comprise more than 60% 11 12 of the Brakleen blends) are known to present potential analytical interference 13 14 15 with NMAM 1501 determinations. 16 17 “TYPICAL” AND “WORST CASE” MISCHARACTERIZATIONS 18 19 Because Short Reports have limited generalizability, the authors should 20 21 22 not have offered their opinion that the results are representative of typical and 23 24 worst case exposures that a mechanic would encounter while using Brakleen 25 26 products. The assertions that the simulations corresponded to “typical use of an 27 28 29 aerosol brake cleaner,” and that some high-temperature/low-air-speed conditions 30 31 encountered represented “worst-case workplace conditions,” are offered absent 32 33 independent verification and seem based on the authors’ opinion. The fact is the 34 35 authors studied one mechanic in one facility during eight uses of a brake cleaner. 36 37 38 The assertions are unfounded because the authors do not consider 39 40 environmental conditions and patterns of use encountered by mechanics in 41 42 countless other workplaces. The fact is that benzene exposures are known to 43 44 45 occur under widely different conditions. To this point, CRC has not monitored 46 47 benzene exposure during the use of Brakleen products because: “We wouldn’t 48 49 be able to properly reproduce every possible scenario that a mechanic would 50 51 52 encounter. There’s so many environmental conditions that need to be measured 53 54 in any specific test that if we were to test in one area and come up with the 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 6 of 9

1 2 3 results, they would probably not be meaningful to the next person in another 4 5 (12) 6 scenario.” 7 8 CONCLUSION 9 10 Because this Short Report communicates inaccurate and misleading findings, it 11 12 is recommended that readers exercise caution in interpreting and applying the 13 14 15 results. 16 17 ACKNOWLEDGEMENTS 18 19 I am a voting member of three ASTM Committees, including one (D02) that 20 21 22 evaluates analytical methods for determining the properties of petrochemical 23 24 products (including benzene content). I have testified opposite Dr. Williams in 25 26 numerous benzene exposure cases, including at least one involving CRC 27 28 29 Industries as a defendant. I recently learned that Dr. Williams is an expert 30 31 witness in a benzene exposure case involving the use of a non-chlorinated brake 32 33 cleaner in which I am an expert witness for the other side. I have never received 34 35 compensation for preparing published articles. 36 37 38 39 REFERENCES 40 41 1. Fries, M., P. Williams, J. Ovesen, and A. Maier: Airborne exposures 42 43 44 associated with the typical use of an aerosol brake cleaner during vehicle 45 46 repair work. J. Occup. Environ. Hyg. 2018. 15, 7: 531-540 47 48 2. ASTM International. Designation: D362-84. Standard Specification for 49 50 Industrial Grade Toluene. Philadelphia, PA. 1984 51 52 53 3. ASTM International. Designation: D841-01 (Reapproved 2006). Standard 54 55 Specification for Nitration-Grade Toluene. West Conshohocken, PA. 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 7 of 9 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 4. ASTM International. Designation: D5606-01 (Reapproved 2006). 4 5 6 Standard Specification for Toluene Diisocyanate (TDI) Feedstock. West 7 8 Conshohocken, PA 9 10 5. Whitlock, W. Deposition testimony, Whitehead et al. v. Baxter Healthcare 11 12 et al. US District Court for the Eastern District of Missouri, Case No. 4:08- 13 14 15 cv-421, at Pages 45 and 80. March 16, 2010. 16 17 6. Peavy, C.C. The importance of platinum in petroleum refining. Platinum 18 19 Metals Rev. Volume 2 (2), 48-52. 1958 20 21 22 7. United States Environmental Protection Agency. Locating and 23 24 estimating air emissions from sources of toluene. EPA-454/R-93-047. 25 26 March 1994. 27 28 29 8. ASTM International. Designation: D841-13. Standard Specification for 30 31 Nitration-Grade Toluene. West Conshohocken, PA. 32 33 9. Selisker, A. Deposition testimony, Ewen et al v. Radiator Specialty et al. 34 35 Superior Court of the State of Washington, Case No. 09-2-06135-7, at 36 37 38 pages 66 and 88. May 18, 2010 39 40 10. ASTM D 2306-00. Standard Test Method for C8 Hydrocarbon Analysis by 41 42 Gas Chromatography. West Conshocken, PA. 43 44 th 45 11. Grob, R.L. and E.F. Barry. Modern Practice of Gas Chromatography. 4 46 47 Edition. ISBN 0-471-22983-0. John Wiley and Sons. 2004 48 49 12. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition., 50 51 52 Method Hydrocarbons, Aromatic: Method 1501. March 15, 2003 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 8 of 9

1 2 3 13. Sigma-Aldrich. Toluene dried. Product 1.08326. 4 5 6 https://www.sigmaaldrich.com/catalog/product/mm/108326?lang=en®io 7 8 n=US. (Last accessed July 2, 2018) 9 10 14. Chevron Phillips Chemical Company: Material Safety Data Sheet 11 12 (#3476) for Toluene (Reference Fuel). The Woodlands, TX. Revision Date 13 14 15 August 15, 2002. 16 17 15. Chevron Phillips Chemical Company: “Safe Handling and Storage of 18 19 Toluene.” The Woodlands, Texas: Chevron Phillips Chemical Company, 20 21 22 2006 23 24 16. Equistar Chemicals LLP: “Material Safety Data Sheet for Toluene 25 26 Nitration.” Houston, Texas: Equistar, 2008 27 28 29 17. Kopstein, M. Estimating airborne benzene exposures from air monitoring 30 31 data for mineral spirits. J. Occup. Environ. Hyg. 2011. 3: 1-8 32 33 18. Total Petrochemicals and Refining: Material Safety Data Sheet for 34 35 Toluene. Houston, TX. March 7, 2013. 36 37 38 19. Total Petrochemicals and Refining: Product Summary Toluene. May 39 40 2017 41 42 20. Chevron Phillips Chemical Company. Material Safety Data Sheet for 43 44 45 Toluene (Commercial Grade). The Woodlands, Texas. July 21, 2003 46 47 21. Equistar Chemicals, LLP: “Material Safety Data Sheet for Toluene 48 49 Commercial Grade.” Houston, Texas: Equistar, 2003. 50 51 52 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 9 of 9 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 Table 1: Benzene Content of Different Toluene Grades 4 5 6 TYPE OF TOLUENE YEAR BENZENE CONTENT PPM w/w 7 unless otherwise stated 8 Blend A Toluene (Note 1) 2018 3.66 9 Ultra Pure(13) (Note 2) 2018 Up to 100 10 Hillman (Note 3) 1978 Can be greater than 1,000 11 (14) 12 Reference Grade (Note 4) 2002 Up to 1,000 ppm (15) 13 Nitration (Note 5) 2006 20,000 14 Nitration(16) (Note 5) 2008 20,000 (up to 50,000) 15 Nitration(17) (Note 5) 2011 Up to 2.29% (molar) 16 Unspecified(18) 2013 2,000 17 (19) 18 Unspecified (Note 6) 2017 Greater than 1,000 (20) 19 Commercial (Note 7) 2000 Up to 25,000 20 Commercial(21) (Note 7) 2014 Up to 15,000 21 22 Note 1: CRC never performed analytical testing to measure the amount of 23 benzene in incoming shipments of toluene used in Brakleen.(12) 24 25 Note 2: Purity guaranteed to be higher than 99.9%; $125 per 150 ml septum 26 Note 3: Reference #2 in the Short Report refers to toluene as a “benzene 27 critical” solvent that has “typically presented problems because it can contain 28 relatively high benzene contents (greater than 0.1 percent benzene).” 29 Note 4: Purity higher than 99.9% (per ASTM TDI Feedstock Toluene); MSDS has 30 benzene carcinogenicity warning. 31 Note 5: In 2013 ASTM established a minimum purity specification (98.8%) for 32 (8) 33 nitration grade toluene - no maximum benzene specification 34 Note 6: Document discloses that toluene is a Category 1A carcinogen because it 35 contains more than 1,000 ppm benzene 36 Note 7: Does not specify whether nitration or industrial grade (both grades are 37 used as solvents). 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only

Journal of Occupational and Environmental Hygiene

Letter to the Editor regarding "Airborne exposures associated with the typical use of an aerosol brake cleaner during vehicle repair work"

Journal: Journal of Occupational & Environmental Hygiene

Manuscript ID JOEH-18-0117.R2

Manuscript Type: Letter to the Editor

benzene exposure, toluene, brake cleaner, industry funded, analytical Keyword: testing

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1 2 3 4 Letter to the Editor regarding “Airborne exposures associated 5 with the typical use of an aerosol brake cleaner during vehicle 6 7 repair work” 8 9 Key Words: Benzene exposure; brake cleaner; industry funded; toluene 10 11 12 Exposition Word Count: 1,614 13 14 INTRODUCTION 15 16 17 In this letter I discuss scientific errors, inaccurate statements, and undisclosed conflicts of 18 19 interest in the Short Report (SR), Airborne exposures associated with the typical use of 20 21 (1) 22 an aerosol brake cleaner during vehicle repair work. Letters to the Editor and 23 24 Commentaries augment the peer review process by providing important checks and 25 26 balances to help ensure that results reported in published articles have scientific merit. In 27 28 29 this regard, I previously commented on another benzene exposure article in a letter to the 30 31 editor.(2) More recently, I critiqued the occupational exposure section of the most recent 32 33 IARC Benzene Monograph in a published Commentary.(3) Others have done so as well.(4, 34 35 5) 36 37 38 Undisclosed Conflicts of Interest 39 40 The authors do not reference an unpublished benzene exposure report(6) (“CRC report” 41 42 43 dated January 20,2017). Nor do they disclose that conclusions, figures, and tables offered 44 45 in the SR come directly from that report. I believe the “in-field exposure study” of 46 47 August 4-5, 2016, and the CRC report that followed a few months later, were not 48 49 50 exercises in academic research. They pertained to benzene exposure litigation involving 51 52 the sponsor, CRC Industries. The SR does not disclose the fact that as a testifying expert 53 54 for CRC, one of the authors (PDRW) referenced the CRC report in at least two court 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 2 of 10

1 2 3 cases (Simmons(7) and Pennington(8)) to buttress her opinions about benzene exposures 4 5 6 arising from non-chlorinated Brakleen products. 7 8 The SR Draws Heavily from the CRC Report 9 10 11 SR analytical results were first presented in the CRC report. Figures and tables in the SR 12 13 were directly constructed from tabulated results in the CRC report. Three ALS 14 15 Laboratory (“ALS”) reports(9) (all dated August 11, 2016) reflect results from ALS 16 17 analytical testing of bulk Brakleen samples received from PDRW on July 18, 2016. The 18 19 20 ALS-determined compositions of Brakleen blends are tabulated in Appendix 2 of the 21 22 CRC report and in Supplemental Table 1 of the SR. The SR refers to 104 charcoal 23 24 samples collected during the “in-field exposure study” - the same number of airborne 25 26 27 samples for which analytical results are provided in Appendix 3 of the CRC report. 28 29 Supplemental Tables 2, 3, and 4, as well as Figure 2, of the SR are constructed directly 30 31 from the 104 tabulated results in Appendix 3 of the CRC report. They are identical in 32 33 34 terms of amount of product used and measured airborne concentrations. The only 35 36 difference is that Appendix 3 of the CRC report tabulates 104 airborne benzene levels 37 38 below the detection limit, while the published article consolidates the same results in a 39 40 sentence on page 534, “Benzene was not detected in any of the personal, area, and 41 42 3 43 background samples at a detection limit of approximately 0.3 mg/mg (0.1 ppm).” 44 45 ANALYTICAL TESTING OF BULK LIQUID BRAKLEEN BLENDS 46 47 The authors report that ALS analyzed the bulk blends using “the same analytical method 48 49 50 and quality control procedures as for the charcoal air samples.” (Emphasis added) More 51 52 specifically, the authors inform readers that air samples (and thus the bulk blends as well) 53 54 were analyzed by NIOSH 1501 (which is applicable to air samples only). I note that the 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 3 of 10 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 Agilent DB-MTBE capillary column discussed in the SR is applicable to MTBE in soil 4 5 (10) 6 and water matrices. 7 8 The three ALS reports identify “Gas-Chromatography-Rinsate IH-001” (“IH- 9 10 001”) as the method used to analyze the bulk Brakleen blends, and indicate that chain of 11 12 custody seals were not present for sample bottles and shipping containers received from 13 14 15 E Risk Science. Method IH-001 (not offered in the ALS Test Catalog and Fee 16 17 Schedule(11)) appears to be an in-house test whose performance properties (e.g., detection 18 19 limit, precision, reporting limits, interferences) have not been peer-reviewed. In general, 20 21 22 it is a good idea for authors to communicate details about unpublished analytical 23 24 methods, as well as about standard methods that have been modified, so reviewers and 25 26 readers can better understand the method and evaluate the results. 27 28 29 Of additional concern is the fact that ketones and alcohols (which comprise more 30 31 than 60% of the Blend A standard) are known to present potential interferences with 32 33 NMAM 1501 determinations. This important concern is not referred to in the SR, but is 34 35 acknowledged in the CRC report, “Note that methanol and acetone (two of the primary 36 37 38 constituents of the Brakleen® formulations) are not designated analytes per the NIOSH 39 40 1501 method.” It is unclear why the authors did not request ALS to analyze air samples 41 42 by OSHA Method 12 (offered in the ALS catalog) and for which there are minimal 43 44 45 interferences. 46 47 Curiously, the authors acknowledge that ALS is unaccredited to perform bulk 48 49 sample analyses. That lack of accreditation is certainly not ALS’s fault. The authors - or 50 51 (12) 52 CRC Industries - should have engaged a laboratory accredited in ASTM D7504 to 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 4 of 10

1 2 3 determine the benzene content of toluene used to formulate the Blend A, after which the 4 5 6 Blend A benzene content could have been accurately calculated. 7 8 Benzene Content of the Blend a Standard and Toluene 9 10 11 For the “in field exposure study”, CRC prepared a Blend A standard to replicate the 12 13 recipe for a historical Brakleen product (sold between 1999 and 2011 according to the 14 15 CRC report): toluene (38.3%), methanol (35.5%, acetone (19.5%), CO2 (6.5%), and 16 17 xylene (0.2%). The authors claim their reported benzene content for Blend A (1.4 ppm) 18 19 20 is “consistent with current supplier certificates of analysis [COAs] for the main 21 22 hydrocarbon ingredient (toluene), but which do not necessarily reflect historical levels.” 23 24 The COAs are not identified, and will be discussed further. The suggestion that current 25 26 27 benzene levels in toluene are lower than in the past is incorrect because the refinery 28 29 process for making toluene is unchanged for at least fifty years; catalytic reforming, 30 31 followed by extraction to remove aliphatic chemicals, followed by distillation. 32 33 34 More importantly, the reported 1.4 ppm benzene content of Blend A would 35 36 require the toluene to contain only 3.66 ppm benzene. The latter is consistent with a 37 38 laboratory-grade reagent, which is far too expensive for use in a commercial solvent 39 40 cleaner. Even ultrapure (>99.9%) TDI-grade toluene(13) may contain 300 ppm benzene 41 42 43 (up to 82-fold more than in Blend A toluene). In fact, CRC has historically used a far 44 45 less pure toluene (nitration-grade) to manufacture Brakleen products; nitration-grade 46 47 toluene(14, 15) has never had a benzene specification, and until 2013 had no minimum 48 49 50 purity requirement. The prospect that toluene used in commercial Brakleen products 51 52 contains only 3.66 ppm benzene, at present and/or in the past, is highly improbable. 53 54 For the “in field exposure study”, CRC is said to have “spiked” Blend A with pure 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 5 of 10 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 benzene to achieve “targeted” benzene contents of 100 ppm (Blend B) and 1,000 ppm 4 5 6 (Blend C). This exercise intimates that historic Brakleen (which is the subject of many 7 8 benzene exposure lawsuits) contained no more than 1,000 ppm benzene (an important 9 10 threshold in benzene exposure litigation). The 1,000 ppm value does not comport with 11 12 two results for non-chlorinated carburetor cleaners (known to have formulations similar 13 14 15 to brake cleaners) reported in SR reference #5. The first was a carburetor cleaner 16 17 formulated with toluene, methanol, and acetone (ID#525308 in the study) found to 18 19 contain 9,000 ppm benzene. Because it comprised only a fraction of the product, the 20 21 22 toluene used certainly contained well in excess of 10,000 ppm benzene - consistent with 23 24 benzene contents for toluene reported in two of my published articles(16, 17). The second 25 26 carburetor cleaner (ID#225108 in the study) contained 2,000 ppm benzene. I note that all 27 28 29 but one of the brake cleaners in the study (including a CRC Brakleen product) were 30 31 chlorinated, and therefore not expected to contain much benzene. 32 33 Certificates of Analysis 34 35 36 Verifying the accuracy of COAs, and the importance of independent, third party 37 38 analytical testing of purchased raw materials, are widely understood to be very 39 40 important(18). A well known gas chromatography textbook warns that analytical methods 41 42 (19) 43 referred to in COAs should be “critically reviewed.” To this point, in discussing the 44 45 sampling and testing of raw materials, the US Food and Drug Administration (FDA) 46 47 writes, “As a minimum, a complete analysis should be performed at appropriate intervals 48 49

50 and compared with COAs. Reliability of COAs should be checked at regular intervals.” 51 52 (20) A topical example underscores why it is bad practice to accept unverified COAs as 53 54 valid laboratory records. A major manufacturer and distributor of toluene produced 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 6 of 10

1 2 3 COAs in which ASTM D2306(21) was listed as the analytical test used to measure 4 5 6 benzene content (some of the COAs actually reported a benzene content of 0.0 ppm) even 7 8 though the test has nothing at all to do with assaying benzene in toluene (it determines the 9 10 distribution of ethyl benzene and three xylene isomers present in xylene mixtures). 11 12 Because COAs do not represent laboratory records, and because the authors cannot 13 14 15 confirm the accuracy of their unreferenced toluene COAs, it was improper of them to 16 17 suggest they corroborate the reported result that the Blend A standard contained 1.4 ppm 18 19 benzene. 20 21 22 “Typical” and “Worst Case” Mischaracterizations 23 24 Short Reports “should acknowledge that the findings might only apply to the limited 25 26 27 sites/conditions included in the study” because they present “a relatively small number of 28 29 measurements.”(22) In this instance, the authors studied just one mechanic in one facility 30 31 during eight uses of a brake cleaner. The authors readily acknowledge a “paucity of data” 32 33 34 and a “limited dataset” on benzene exposures arising from the use of aerosolized non- 35 36 chlorinated brake cleaners. Based on these circumstances, the conclusions offered by the 37 38 authors that the results are representative of “typical” and “worst case” exposures a 39 40 mechanic would encounter are inappropriate and misleading. They seem based on the 41 42 43 authors’ opinion and are offered absent independent verification. 44 45 CONCLUSION 46 47 48 Because this Short Report communicates inaccurate and misleading findings, it is 49 50 recommended that readers exercise caution in interpreting and applying the results. 51 52 53 Documents not available to the public (e.g., COAs; SOP for IH-001) should be cited and 54 55 produced to the journal. 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 7 of 10 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 4 ACKNOWLEDGMENTS 5 6 I am a voting member of three ASTM Committees, including one (D02) that evaluates 7 8 9 analytical methods for determining the properties of petrochemical products (including 10 11 benzene content). As a chemical engineer, I testify on behalf of workers who were 12 13 exposed to brake cleaners and other benzene-containing products. Almost thirteen years 14 15 (23) 16 ago I neglected to disclose this in a published article. I have testified opposite Dr. 17 18 Williams in at least one case in which CRC was a defendant, and in a current lawsuit 19 20 (involving the use of a non-chlorinated brake cleaner) in which Dr. Williams formerly 21 22 served as an expert witness. I have never received compensation for preparing published 23 24 25 articles. 26 27 REFERENCES 28 29 30 1. Fries, M., P. Williams, J. Ovesen, and A. Maier: Airborne exposures associated 31 32 with the typical use of an aerosol brake cleaner during vehicle repair work. J. 33 34 35 Occup. Environ. Hyg. 2018. 15, 7: 531-540 36 37 2. Kopstein, M. Letters to the Editor. Comparison of exposure measurements to 38 39 near field-far field modeled results for benzene and base solvents during a 40 41 42 cleaning process using plain or 0.1% benzene spiked toluene and xylene. JCH&S. 43 44 2013. March/April. 1-4 45 46 3. Kopstein, M. Commentary. Critique of the IARC 100F working group evaluation 47 48 49 of occupational benzene exposure: suggestions for the October 2017 benzene- 50 51 only working group meeting. New Solut. 2018. 28,1: 10-23 52 53 4. Infante, P. The IARC October evaluation of benzene carcinogenicity was 54 55 incomplete and needs to be reconsidered. Am J Ind Med 2011.54:157-164 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 8 of 10

1 2 3 5. Kelland, K. WHO cancer agency “left out key findings” in benzene review. 4 5 6 Reuters. 2018. February 28. 7 8 6. Fries, M., P. Williams, J. Ovesen, and A. Maier: Unpublished Report: 9 10 Workplace/simulation study of benzene and total hydrocarbon (THC) exposures 11 12 associated with an aerosol brake cleaner. January 20, 2017. Prepared for CRC 13 14 15 Industries, Inc. 16 17 7. Williams, P. Expert report of Pamela Williams, MS, ScD, CIH: Simmons et al. v. 18 19 US Steel et al. August 7, 2017 20 21 22 8. Williams, P. Expert report of Pamela Williams, MS, ScD, CIH: Pennington et al. 23 24 v. US Steel et al. March 2, 2018 25 26 9. ALS Environmental. Three reports prepared for E Risk Sciences, LLP: CRC 27 28 29 Project. August 11, 2016. 30 31 10. Agilent Technologies. GC and GC/MS your essential resource for columns and 32 33 supplies. https://www.agilent.com/cs/library/catalogs/public/5991- 34 35 5213EN_GC_Catalog_Columns.pdf Last accessed December 7, 2018. 36 37 38 11. ALS. Test catalog and fee schedule. 39 40 https://www.alsglobal.com/locations/americas/north-america/usa/ohio/cincinnati- 41 42 environmental. Last accessed December 7, 2018. 43 44 45 12. ASTM International. D7504-17a. Standard test method for trace impurities in 46 47 monocyclic aromatic hydrocarbons by gas chromatography and effective carbon 48 49 number. West Conshohocken. PA 50 51 52 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Page 9 of 10 Journal of Occupational and Environmental Hygiene-For Peer Review Only

1 2 3 13. ASTM International. Designation: D5606-01 (Reapproved 2006). Standard 4 5 6 Specification for Toluene Diisocyanate (TDI) Feedstock. West Conshohocken, 7 8 PA. 9 10 14. ASTM International. Designation: D841-12. Standard Specification for 11 12 Nitration-Grade Toluene. West Conshohocken, PA. 13 14 15 15. ASTM International. Designation: D841-13. Standard Specification for 16 17 Nitration-Grade Toluene. West Conshohocken, PA. 18 19 16. Kopstein, M. Estimating airborne benzene exposures from air monitoring data for 20 21 22 mineral spirits. 2011. J. Occup. Environ. Hyg. 8:5, 300-309 23 24 17. Peckham, T., Kopstein, M., Klein, J., and J. Dahlgren. Benzene-contaminated 25 26 toluene and acute myeloid leukemia: a case review of literature. Toxicol Ind 27 28 29 Health. 2014. 30(1):73-81. 30 31 18. California Military Environmental Coordination Committee. Best practices 32 33 for the detection and deterrence of laboratory fraud. March 1997 34 35 19. Grob, R and E.F. Barry. Modern practice of gas chromatography. 4th Edition. 36 37 38 2004. 39 40 20. United States Food and Drug Administration. Manufacturing practice guidance 41 42 for active pharmaceutical ingredients. 43 44 45 https://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformati 46 47 on/Guidances/UCM073497.pdf Last accessed December 7, 2018. 48 49 21. ASTM International. D 2306-00. Standard test method for C8 hydrocarbon 50 51 52 analysis by gas chromatography (Withdrawn 2006). West Conshocken, PA. 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected] Journal of Occupational and Environmental Hygiene-For Peer Review Only Page 10 of 10

1 2 3 22. Kopstein, M. Potential uses of petrochemical products can result in significant 4 5 6 benzene exposures: MSDSs must list benzene as an ingredient. J. Occup. Environ. 7 8 Hyg. 2006. 3:1-8. 9 10 23. Anthony, R. From the Editor: Research manuscripts - short report vs. technical 11 12 manuscript. J. Occup. Environ. Hyg. 2018. Vol. 15. 11:D69-D70 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/joeh; E-mail: [email protected]