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ID:62270422
大小:1.28 MB
页数:142页
时间:2021-04-24
《最新有机溶剂的特性(精)课件PPT.ppt》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
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
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