Influence of Varying Environmental Conditions on the ... · Polyurethane Foam (PUF) is a minor...
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Influence of Varying Environmental Conditions on the Leaching of Flame Retardant Additives from Polyurethane Foam Microplastics Meredith Evans, Drew Luellen, Mark LaGuardia, Kelley Uhlig and Robert Hale Department of Aquatic Health Sciences, Virginia Institute of Marine Science, College of William & Mary,1375 Greate Road, Gloucester Point, VA 23062; contact: [email protected] Introduction Polyurethane Foam (PUF) is a minor constituent of marine debris but - PUF rapidly fragments into smaller plastics à greater surface area - PUF contains high concentrations of harmful chemical additives Objective: evaluate the release of flame retardant additives from PUF under varying aquatic conditions. Polyurethane Chemical Additives Polyurethane Foam may be amended with % concentrations of flame retardant (FR) additives, including: Brominated Flame Retardants (BFRs) 2,2’,4,4’-tetrabromodiphenyl ether (BDE-47)* 2,2’,4,4’,6-pentabromodiphenyl ether (BDE-100)* 2,2’,4,4’,5-pentabromodiphenyl ether (BDE-99)* 2,2’,4,4’,5,6’-hexabromodiphenyl ether (BDE-154)* 2,2’,4,4’,5,5’-hexabromodiphenyl ether (BDE-153)* 2-ethylhexyl 2, 3, 4, 5-tetrabromobenzoate (TBB) ⁺ 2-ethylhexyl 2, 3, 4, 5-tetrabromophthalate (TBPH) ⁺ Organophosphate Ester Flame Retardants (PFRs) tris (2-chloroethyl) phosphate (TCEP) tris (1-chloro-2-propyl) phosphate (TCPP) tris (1,3-dichloro-2-propyl) phosphate (TDCPP) triphenyl phosphate (TPP) Some BFR are chemically similar to PCBs. BFRs that have not already been removed from commerce are under chemical assessment review by the EPA. All above PFRs are listed as problem formulations by the EPA. Many FRs are known endocrine disruptors. * Discontinued in 2004 or prior due to toxicity effects, but still found in older furniture and PUF products ⁺ Consistent with flame retardant Firemaster® 550 References & Acknowledgements https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/fact-sheet- assessing-risks-flame-retardants La Guardia & Hale. 2015. Halogenated flame-retardant concentrations in settled dust, respirable and inhalable particulates and polyurethane foam at gymnastic training facilities and residences. Environ. Int. 79, 106 - 114. Support received from the NOAA Marine Debris Program, ICF International & U.S. EPA Methods PUF Microplastic (53-300µm) were loaded into a column and leached with 1 liter of test condition water (see table for example), isolating one water variable and keeping the remainder constant. BFR and PFR leachates were analyzed by LC/MS. Here, only PUF particles of size range 53-300µm are reported. However, PUF of other size ranges and two UV exposures were evaluated for surface area using the Brunauer, Emmett and Teller (BET) approach. UV pre-exposure of microplastics was preformed via Q-Sun Xenon Test Chamber for 0, 500 and 1000 hours (equivalent to ~ 0, 6 and 12 months of sunlight). Two synthetic digestive fluid proxies were used: sodium taurocholate (STC) and sodiumdodecylsulfate (SDS) at 10 mM each. 1 10 100 1000 10000 BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH Concentration (ng/L) Effect of Temperature 1 10 100 1000 10000 100000 TCEP TCPP TDCPP TPP 4°C 20°C 40°C 1 10 100 1000 10000 BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH Concentration (ng/L) Effect of Salinity 1 10 100 1000 10000 100000 1000000 TCEP TCPP TDCPP TPP 0 psu 15 psu 35 psu 1 10 100 1000 10000 100000 BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH Concentration (ng/L) Effect of Digestive Fluid 1 10 100 1000 10000 100000 1000000 TCEP TCPP TDCPP TPP 0 10 SDS 10 STC 1 10 100 1000 10000 100000 BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH Concentration (ng/L) Effect of Humic Acid 1 10 100 1000 10000 100000 1000000 TCEP TCPP TDCPP TPP 0 mg/L 5 mg/L 10 mg/L 100 mg/L 1 10 100 1000 10000 BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH Concentration (ng/L) Effect of Surface Area 1 10 100 1000 10000 100000 TCEP TCPP TDCPP TPP 0.73 m2/g 0.53 m2/g 0.46 m2/g 1 10 100 1000 10000 BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH Concentration (ng/L) Effect of UV exposure time 1 10 100 1000 10000 100000 TCEP TCPP TDCPP TPP 0 hours 500 hours 1000 hours Results Test H 2 0 Conditions Baseline Eg: Humic Acid test Temp. C 40 40 Salinity (psu) 0 0 Humic Acid (mg/L) 0 10 Digestive Fluid 0 0 UV Exposure time 0 0 Temperature Incubator 1 Liter Test H 2 0 PUF Sand Filter LC-MS FR quantification Surrogate Spiking DCM extraction Experimental Design: Surface Area Effects BET approach to measure surface area of different size PUF. PUF particle size is inversely related to surface area. UV exposure decreased chemical surface area relative to non- UV exposed PUF of the same size range, but PUF was not exposed to physical stress following UV, and would likely show increased surface area with physical degradation. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 <53 µm 53-300 µm 300-1000 µm 500hr UV 53-300 µm 1000hr UV 53-300 µm BET Surface Area (m 2 /g) Particle Size Category and UV treatment PUF Surface Area UV Exposure Effects SEM of non-UV exposed PUF particle 53-300µm SEM of UV exposed PUF particle, 53-300µm Scanning Electron Microscopy (SEM) images reveal minimal physical changes with UV weathering , but caused visible yellowing. The fragility of the PUF increased, however, and would have fractured more if exposed to subsequent frictional stress. Discussion PUF is found in couch cushions, mattresses, carpet underlayment and other household products. Salinity BFR Leaching PFR Leaching Temperature Digestive Fluid Humic Acid BFR Leaching Surface Area UV Exposure No change in BFR Leaching No change in PFR Leaching ü PFRs responded to different water conditionsless than BFRs, potentially due to greater leaching rates suggesting PFRs are more readily released from PUF. Illustrated by PFR concentration tracked over 10 days: PFR leaching over 10 days in 40°C and 100 mg/L Humic Acid Sampling Time (days) Concentration of PFR (ng/L) ü Surface area results for PUF 53-300µm were not as expected, likely due to narrow range (0.46-0.73 m 2 /g). Differences would be expected between different size classes (<53µm and >300µm). ü UV exposure visibly changed PUF, but minimally affected leachate and inversely affected surface area. Subsequent physical degradation would likely counter theses results. ü Suggested PUF pollution areas with notable aquatic health concern: Warm temperatures Freshwater or saltwater Digestive tracts High natural organics content Flame retardant concentrations following hurricanes and floods in standing water and runoff Debris containing PUF following disaster cleanup. Credit: fema.org
Transcript of Influence of Varying Environmental Conditions on the ... · Polyurethane Foam (PUF) is a minor...
InfluenceofVaryingEnvironmentalConditionsontheLeachingofFlameRetardantAdditivesfromPolyurethaneFoamMicroplasticsMeredithEvans,DrewLuellen,MarkLaGuardia,KelleyUhlig andRobertHaleDepartmentofAquaticHealthSciences,VirginiaInstituteofMarineScience,CollegeofWilliam&Mary,1375Greate Road,GloucesterPoint,VA23062;contact:[email protected]
IntroductionPolyurethaneFoam(PUF)isaminorconstituentofmarinedebrisbut
- PUFrapidlyfragmentsintosmallerplasticsà greatersurfacearea
- PUFcontainshighconcentrationsofharmfulchemicaladditives
Objective:evaluatethereleaseofflameretardantadditivesfromPUFundervaryingaquaticconditions.
PolyurethaneChemicalAdditivesPolyurethaneFoammaybeamendedwith%concentrationsofflameretardant(FR)additives,including:
BrominatedFlameRetardants(BFRs)2,2’,4,4’-tetrabromodiphenylether(BDE-47)*2,2’,4,4’,6-pentabromodiphenylether(BDE-100)*2,2’,4,4’,5-pentabromodiphenylether(BDE-99)*2,2’,4,4’,5,6’-hexabromodiphenylether(BDE-154)*2,2’,4,4’,5,5’-hexabromodiphenylether(BDE-153)*2-ethylhexyl2,3,4,5-tetrabromobenzoate(TBB) ⁺2-ethylhexyl2,3,4,5-tetrabromophthalate(TBPH) ⁺
OrganophosphateEsterFlameRetardants(PFRs)tris (2-chloroethyl)phosphate(TCEP)tris (1-chloro-2-propyl)phosphate(TCPP)tris (1,3-dichloro-2-propyl)phosphate(TDCPP)triphenyl phosphate(TPP)
SomeBFRarechemicallysimilartoPCBs.BFRsthathavenotalreadybeenremovedfromcommerceareunderchemicalassessmentreviewbytheEPA.AllabovePFRsarelistedasproblemformulationsbytheEPA.ManyFRsareknownendocrinedisruptors.
*Discontinuedin2004orpriorduetotoxicityeffects,butstillfoundinolderfurnitureandPUFproducts
⁺ConsistentwithflameretardantFiremaster®550
References&Acknowledgementshttps://www.epa.gov/assessing-and-managing-chemicals-under-tsca/fact-sheet-assessing-risks-flame-retardants
LaGuardia&Hale.2015.Halogenatedflame-retardantconcentrationsinsettleddust,respirable andinhalableparticulatesandpolyurethanefoamatgymnastictrainingfacilitiesandresidences.Environ.Int. 79,106- 114.
SupportreceivedfromtheNOAAMarineDebrisProgram,ICFInternational&U.S.EPA
MethodsPUFMicroplastic(53-300µm)wereloadedintoacolumnandleachedwith1literoftestconditionwater(seetableforexample),isolatingonewatervariableandkeepingtheremainderconstant.BFRandPFRleachateswereanalyzedbyLC/MS.
Here,onlyPUFparticlesofsizerange53-300µmarereported.However,PUFofothersizerangesandtwoUVexposureswereevaluatedforsurfaceareausingtheBrunauer,EmmettandTeller(BET)approach.UVpre-exposureofmicroplasticswaspreformedviaQ-SunXenonTestChamberfor0,500and1000hours(equivalentto~0,6and12monthsofsunlight).Twosyntheticdigestivefluidproxieswereused:sodiumtaurocholate (STC)andsodium dodecyl sulfate(SDS)at10mM each.
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BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH
Concentration(ng/L)
EffectofTemperature
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TestH2 0Conditions Baseline Eg:HumicAcidtest
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HumicAcid(mg/L) 0 10DigestiveFluid 0 0
UVExposuretime 0 0
TemperatureIncubator
1LiterTestH20
PUF SandFilter
LC-MSFRquantificationSurrogateSpiking
DCMextraction
ExperimentalDesign:
SurfaceAreaEffectsBETapproachtomeasuresurfaceareaofdifferentsizePUF.
PUFparticlesizeisinverselyrelatedtosurfacearea.UVexposuredecreasedchemicalsurfacearearelativetonon-UVexposedPUFofthesamesizerange,butPUFwasnotexposedtophysicalstressfollowingUV,andwouldlikelyshowincreasedsurfaceareawithphysicaldegradation.
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SEMofnon-UVexposedPUFparticle53-300µm SEMofUVexposedPUFparticle,53-300µm
ScanningElectronMicroscopy(SEM)imagesrevealminimalphysicalchangeswithUVweathering,butcausedvisibleyellowing.ThefragilityofthePUFincreased,however,andwouldhavefracturedmoreifexposedtosubsequentfrictionalstress.
Discussion
PUFisfoundincouchcushions,mattresses,carpetunderlaymentandotherhousehold
products.
Salinity BFRLeachingPFRLeaching
TemperatureDigestiveFluidHumic Acid
BFRLeaching
SurfaceAreaUVExposure
NochangeinBFRLeachingNochangeinPFRLeaching
ü PFRsrespondedtodifferentwaterconditionslessthanBFRs,potentiallyduetogreaterleachingratessuggestingPFRsaremorereadilyreleasedfromPUF.IllustratedbyPFRconcentrationtrackedover10days:
PFRleachingover10daysin40°Cand100mg/LHumic Acid
SamplingTime(days)
ConcentrationofPFR(ng/L)
ü SurfacearearesultsforPUF53-300µmwerenotasexpected,likelyduetonarrowrange(0.46-0.73m2/g).Differenceswouldbeexpectedbetweendifferentsizeclasses(<53µmand>300µm).
ü UVexposurevisiblychangedPUF,butminimallyaffectedleachateandinverselyaffectedsurfacearea.Subsequentphysicaldegradationwouldlikelycounterthesesresults.
ü SuggestedPUFpollutionareaswithnotableaquatichealthconcern:
WarmtemperaturesFreshwaterorsaltwater
DigestivetractsHighnaturalorganicscontent
Flameretardantconcentrationsfollowinghurricanesandfloodsinstandingwaterandrunoff
DebriscontainingPUFfollowingdisastercleanup.Credit:fema.org
