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:mevans@vims.edu

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

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BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH

Concentration(ng/L)

EffectofTemperature

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TCEP TCPP TDCPP TPP

4°C

20°C

40°C

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BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH

Concentration(ng/L)

EffectofSalinity

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TCEP TCPP TDCPP TPP

0psu

15psu

35psu

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BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH

Concentration(ng/L)

EffectofDigestiveFluid

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1000000

TCEP TCPP TDCPP TPP

0

10SDS

10STC

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BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH

Concentration(ng/L)

EffectofHumicAcid

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TCEP TCPP TDCPP TPP

0mg/L

5mg/L

10mg/L

100mg/L

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BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH

Concentration(ng/L)

EffectofSurfaceArea

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TCEP TCPP TDCPP TPP

0.73m2/g

0.53m2/g

0.46m2/g

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BDE-47 BDE-100 BDE-99 BDE-154 BDE-153 TBB TBPH

Concentration(ng/L)

EffectofUVexposuretime

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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

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0.5

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<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