最新有机溶剂的特性(精)课件PPT.ppt

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1、有机溶剂的特性(精)有機溶劑的特性溶解性脂溶性（可溶解脂肪）愈強，去脂效能愈佳，對皮膚和神經系統的傷害也愈大可燃性可燃性高者作燃料，不可燃者則作滅火劑。揮發性蒸氣壓愈高，揮發性愈強，空氣中有機溶劑的濃度愈大，愈多經由呼吸道吸入人體。化學結構一般而言，結構相似者毒性可能相近，例如鹵化有機溶劑（四氯甲烷，三氯乙烯，四氯乙烯等），對肝皆具毒性。也可能差很多，2,4-diaminotoluene(livertumor)/2,6-diaminotoluene(not)Themaindeterminantsofasolvent’sinherenttoxicitythenumber

2、ofcarbonatomlipophilicityvolatilitywhetheritissaturatedorhasdoubleortriplebondsbetweenadjacentcarbonatomsitsconfiguration(straightchain,branchchain,orcyclic)thepresenceoffunctionalgroupsex.Amides/amines-potentsensitizeraldehyde-irritatingOccupationalStandards:TWAThetime-weightedaveragei

3、sthetime-weightedaverageconcentrationforanormal8-hourworkdayor40-hourworkweek,towhichnearlyallworkersmayberepeatedlyexposed,dayafterday,withoutadverseeffect.Asshowninthefigure,timeweightedaveragespermitexcursionsabovethelimitprovidedthattheyarecompensatedbyequivalentexcursionsbelowthe

4、limitduringtheworkweekTWAToillustratetheTWAformula,assumethatasubstancehasan8-hourtime-weightedaveragePELof100ppm.Assumethatanemployeeissubjecttothefollowingexposure:Twohoursexposureat150ppmTwohoursexposureat75ppmFourhoursexposureat50ppm.Substitutingthisinformationintheformula,wehave:

5、TWA=(150)(2)+(75)(2)+(50)(4)=81.25ppm                             8Since81.25ppmislessthan100ppm,the8-hourtime-weightedaveragelimit,theexposureisacceptableShort-TermExposureLimit(TLV-STEL)themaximumconcentrationtowhichworkerscanbeexposedcontinuouslyforashortperiodoftime(15-minute)witho

6、utsufferingfromirritation,chronicorirreversibletissuechange,ornarcosisofsufficientdegreetoincreaseaccidentproneness,impairself-rescue,ormateriallyreduceworkefficiency.Ceiling(TLV-C)Ceiling(TLV-C)istheconcentrationthatshouldnotbeexceededeveninstantaneously.Forsomesubstances,forexampleirr

7、itantgases,onlytheTLV-ceilingmayberelevant.GeneralAcuteToxicEffectsCNSdepressionHighlevelexposure中樞神經麻醉效果，例如乙醚麻醉一般而言，碳鏈愈長，含雙鍵、鹵素基（氯、溴、氟等）的溶劑中樞效果愈強。臨床上，暴露的人會頭暈、頭痛、噁心、嘔吐、嗜睡，平衡失調，像醉酒一般，除了影響健康外，勞工甚易發生工作意外。工作場所中常存在多種溶劑或混合物，彼此加強作用，危害比單一物質更大。-SubanestheticdosebehavioraltoxicityDermala