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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.
1
10
100
1000
10000
BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH
Concentration(ng/L)
EffectofTemperature
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)
EffectofSalinity
1
10
100
1000
10000
100000
1000000
TCEP TCPP TDCPP TPP
0psu
15psu
35psu
1
10
100
1000
10000
100000
BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH
Concentration(ng/L)
EffectofDigestiveFluid
1
10
100
1000
10000
100000
1000000
TCEP TCPP TDCPP TPP
0
10SDS
10STC
1
10
100
1000
10000
100000
BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH
Concentration(ng/L)
EffectofHumicAcid
1
10
100
1000
10000
100000
1000000
TCEP TCPP TDCPP TPP
0mg/L
5mg/L
10mg/L
100mg/L
1
10
100
1000
10000
BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH
Concentration(ng/L)
EffectofSurfaceArea
1
10
100
1000
10000
100000
TCEP TCPP TDCPP TPP
0.73m2/g
0.53m2/g
0.46m2/g
1
10
100
1000
10000
BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH
Concentration(ng/L)
EffectofUVexposuretime
1
10
100
1000
10000
100000
TCEP TCPP TDCPP TPP
0hours
500hours
1000hours
Results
TestH2 0Conditions Baseline Eg:HumicAcidtest
Temp.C 40 40Salinity(psu) 0 0
HumicAcid(mg/L) 0 10DigestiveFluid 0 0
UVExposuretime 0 0
TemperatureIncubator
1LiterTestH20
PUF SandFilter
LC-MSFRquantificationSurrogateSpiking
DCMextraction
ExperimentalDesign:
SurfaceAreaEffectsBETapproachtomeasuresurfaceareaofdifferentsizePUF.
PUFparticlesizeisinverselyrelatedtosurfacearea.UVexposuredecreasedchemicalsurfacearearelativetonon-UVexposedPUFofthesamesizerange,butPUFwasnotexposedtophysicalstressfollowingUV,andwouldlikelyshowincreasedsurfaceareawithphysicaldegradation.
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
<53µm 53-300µm 300-1000µm 500hrUV53-300µm
1000hrUV53-300µm
BETSurfaceArea(m
2 /g)
ParticleSizeCategoryandUVtreatment
PUFSurfaceArea
UVExposureEffects
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