1、Designation:E253507(Reapproved 2013)Standard Guide forHandling Unbound Engineered Nanoscale Particles inOccupational Settings1This standard is issued under the fixed designation E2535;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,t
2、he year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONNanometre-scale particles are encountered in nature and in industry in a variety of forms andmaterials.Engineer
3、ed nanoscale particles as a class comprise a range of materials differing in shape,size,and chemical composition,and represent a broad range of physical and chemical properties.Workers within some nanotechnology-related industries and operations have the potential to beexposed to these engineered na
4、noscale particles at levels exceeding ambient nanoscale particleconcentrations through inhalation,dermal contact and ingestion when not contained on or within amatrix(unbound).Occupational health risks associated with manufacturing,processing and handlingunbound nanoscale particles,agglomerates or a
5、ggregates of nanoscale particles are not yet clearlyunderstood.Dominant exposure routes,potential exposure levels and any material hazard are expectedto vary widely among particular nanoscale particle materials and handling contexts.Additionalresearch is needed to understand the impact of these expo
6、sures on employee health and how best todevise appropriate exposure monitoring and control strategies.Until clearer understandings emerge,the limited evidence available suggests caution when potential exposures to unbound engineerednanoscale particles(UNP)may occur.1.Scope1.1 This guide describes ac
7、tions that could be taken by theuser to minimize human exposures to unbound,engineerednanoscale particles(UNP)in research,manufacturing,labora-tory and other occupational settings where UNP may reason-ably be expected to be present.It is intended to provideguidance for controlling such exposures as
8、a cautionary mea-sure where neither relevant exposure standards nor definitivehazard and exposure information exist.1.2 General GuidanceThis guide is applicable to occupa-tional settings where UNP may reasonably be expected to bepresent.Operations across those settings will vary widely inthe particu
9、lar aspects relevant to nanoscale particle exposurecontrol.UNP represent a vast variety of physical and chemicalcharacteristics(for example,morphology,mass,dimension,chemical composition,settling velocities,surface area,surfacechemistry)and circumstances of use.Given the range ofphysical and chemica
10、l characteristics presented by the variousUNP,the diversity of occupational settings and the unevenempirical knowledge of and experience with handling UNPmaterials,the purpose of this guide is to offer general guidanceon exposure minimization approaches for UNP based upon aconsensus of viewpoints,bu
11、t not to establish a standardpractice nor to recommend a definite course of action to followin all cases.1.2.1 Accordingly,not all aspects of this guide may berelevant or applicable to all circumstances of UNP handling.The user should apply reasonable judgment in applying thisguide including conside
12、ration of the characteristics of theparticular UNP involved,the users engineering and otherexperience with the material,and the particular occupationalsettings where the user may apply this guide.Users areencouraged to obtain the services of qualified professionals inapplying this guide.1.2.2 Applic
13、able Where Relevant Exposure Standards DoNot ExistThis guide assumes that the user is aware of and incompliance with any authoritative occupational exposure stan-dard applicable to the bulk form of the UNP.This guide may beappropriate where such exposure standards do not exist,orwhere such standards
14、 exist,but were not developed withconsideration of the nanoscale form of the material.1.3 Applicable Where Robust Risk Information Does NotExistThis guide assumes the absence of scientifically soundrisk assessment information relevant to the particular UNP1This guide is under the jurisdiction of AST
15、M Committee E56 on Nanotech-nology and is the direct responsibility of Subcommittee E56.03 on Environment,Health,and Safety.Current edition approved Sept.1,2013.Published September 2013.Originallyapproved in 2007.Last previous edition approved in 2007 as E2535 07.DOI:10.1520/E2535-07R13.Copyright AS
16、TM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 involved.Where sound risk assessment information exists,orcomes to exist,any exposure control measures should bedesigned based on that information,and not premised on thisguide.Such measures may be more or less stringent than thosesuggested by this guide.1.4 Materials Within ScopeThis guide pertains to un-bound engineered nanoscale particles or their respirable ag-glomerates or aggregates thereof.Re
