1、Designation: E 2535 07Standard Guide forHandling Unbound Engineered Nanoscale Particles inOccupational Settings1This standard is issued under the fixed designation E 2535; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONNanometer-scale particles are encountered in nature and in industry in a variety of forms andmaterials. Engineered n
3、anoscale 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 nano
4、scale 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 o
5、r aggregates 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 thes
6、e exposures 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 de
7、scribes actions 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 su
8、ch exposures as a cautionary mea-sure where neither relevant exposure standards nor definitivehazard and exposure information exist.1.2 General GuidanceThis Guide is applicable to occu-pational settings where UNP may reasonably be expected to bepresent. Operations across those settings will vary wid
9、ely inthe particular aspects relevant to nanoscale particle exposurecontrol. UNP represent a vast variety of physical and chemicalcharacteristics (e.g., morphology, mass, dimension, chemicalcomposition, settling velocities, surface area, surface chemis-try) and circumstances of use. Given the range
10、of physical andchemical characteristics presented by the various UNP, thediversity of occupational settings and the uneven empiricalknowledge of and experience with handling UNPmaterials, thepurpose of this Guide is to offer general guidance on exposureminimization approaches for UNP based upon a co
11、nsensus ofviewpoints, but not to establish a standard practice nor torecommend a definite course of action to follow in 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 t
12、hisGuide including consideration 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 inapp
13、lying this Guide.1.2.2 Applicable 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 maybe appropriate where such exposure standards do no
14、t exist, orwhere such standards 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 UNPinvolved. Wh
15、ere sound risk assessment information exists, orcomes to exist, any exposure control measures should be1This guide is under the jurisdiction of ASTM Committee E56 on Nanotech-nology and is the direct responsibility of Subcommittee E56.03 on Environment,Health, and Safety.Current edition approved Sep
16、t. 15, 2007. Published October 2007.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.designed based on that information, and not premised on thisGuide. Such measures may be more or less stringent than thosesuggested by this Guide.1.4
17、Materials within ScopeThis Guide pertains to un-bound engineered nanoscale particles or their respirable ag-glomerates or aggregates thereof. Relevant nanoscale particletypes include, for example, intentionally produced fullerenes,nanotubes, nanowires, nanoropes, nanoribbons, quantum dots,nanoscale
18、metal oxides, and other engineered nanoscale par-ticles. Respirable particles are those having an aerodynamicequivalent diameter (AED) less than or equal to 10 m (10 000nm) or those particles small enough to be collected with arespirable sampler (12, 34, 36).2The AED describes thebehavior of an airb
19、orne particle and is dependent upon theparticle density, shape, and sizefor instance, a particle with aspherical shape, smooth surface, density of 1.0 g/cc and aphysical diameter of 4 m would have an AED of 4 m,whereas a particle with a spherical shape, smooth surface,density of 11.35 g/cc and a phy
20、sical diameter of 4 m wouldhave an AED of 14 m and would therefore be of a nonrespi-rable size. Respirable fibers are those having physical diam-eters less than or equal to 3 m (3000 nm) or those fibers smallenough to be collected with a thoracic sampler (65, 66).1.5 Materials Beyond Scope:1.5.1 UNP
21、 may be present in various forms, such aspowders or suspensions, or as agglomerates and aggregates ofprimary particles, or as particles dispersed in a matrix. ThisGuide does not pertain to UNP incapable, as a practical matter,from becoming airborne or be expected to generate or releaseUNP in occupat
22、ional settings under the particular circum-stances of use (e.g., UNPs dispersed or otherwise fixed withina solid, strongly bonded to a substrate or contained within aliquid matrix such as aggregated primary crystals of pigmentsin paints). This guide does not pertain to aggregates oragglomerates of U
23、NP that are not of a respirable size.1.5.2 This Guide does not pertain to materials that presentnanoscale surface features, but do not contain UNPs (e.g.,nanoscale lithography products, nanoelectronic structures ormaterials comprised of nanoscale layers).1.5.3 This Guide does not pertain to UNPs whi
24、ch exist innature which may be present in normal ambient atmospheres orare unintentionally produced by human activities, such as bycombustion processes. Nor does it pertain to materials thathave established exposure control programs (e.g. safe handlingprotocols for nanoscale biological agents) or pu
25、blished expo-sure limits such as occupational exposure limits for weldingfumes See Appendix X1.1.6 Handling Considerations Beyond ScopeThe use ofthis Guide is limited to the scope set forth in this section. ThisGuide generally does not address actions related to potentialenvironmental exposures, nor
26、 to exposures potentially arisingat disposal or other end-uses.1.7 Not a Standard of CareThis ASTM standard Guidedoes not necessarily represent the standard of care by which theadequacy of a set of exposure control measures should bejudged; nor should this document be used without consider-ation of
27、the particular materials and occupational circum-stances to which it may be applied. The word “standard” in thetitle means only that the document has been approved throughthe ASTM consensus process.1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its u
28、se. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3E 2456 Terminology Relating to Nanotechnology3. Terminology3.1 Definitions
29、Refer to Terminology E 2456 for defini-tions of terms used within this guide.3.2 Definitions of Terms Specific to This Standard:3.2.1 aerodynamic equivalent diameter (AED), nthe di-ameter of a smooth, unit density ro= 1 gram per cubiccentimeter (g/cm3) sphere that has the same terminal settlingveloc
30、ity as the actual particle (26).3.2.2 agglomerate, nin nanotechnology, a group of par-ticles held together by relatively weak forces (e.g., van derWaals or capillary.) and which may break apart into smallerparticles upon processing.3.2.3 aggregate, nin nanotechnology, a discrete group ofparticles in
31、 which the various individual components are noteasily broken apart, such as in the case of primary particles thatare strongly bonded together (for example, fused, sintered, ormetallically bonded particles).3.2.4 control principle, nthe principle establishes in thisguide that, as a cautionary measur
32、e, occupational exposures tounbound, engineered nanoscale particles (UNP) should beminimized to levels that are as low as is reasonably practicable.3.2.5 nanoscale, adjhaving one or more dimensions onthe order of 1 to 100 nanometers.3.2.6 particle, nin nanotechnology, a small object thatbehaves as a
33、 whole unit in terms of transport and properties.3.2.7 program, na management policy to minimize occu-pational UNP exposures together with the procedures andactions to meet that objective.3.2.8 respirable, adjairborne particles which are smallenough to enter the alveolar (gas-exchange) region of the
34、 lung.3.2.9 inhalable, adjairborne particles which are smallenough to enter the head airways through the nose and/ormouth during inhalation.3.2.10 should, aux., vas used in this guide, indicates thata provision is not mandatory but is recommended as a goodpractice.3.2.11 ultrafine particle, na parti
35、cle smaller than about0.1 micrometer (100 nanometers) in diameter.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book
36、of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.E25350723.2.12 unbound, adjwith reference to engineered nanos-cale particles, those nanoscale particles that are not containedwithin a matrix under normal temperature and pressure condi-tions that wo
37、uld reasonably be expected to prevent the particlesfrom being separately mobile and a potential source of expo-sure. An engineered primary nanoscale particle dispersed andfixed within a polymer matrix, incapable as a practical matterof becoming airborne, would be “bound,” while such a particlesuspen
38、ded as an aerosol would be “unbound”.3.3 Acronyms:3.3.1 HEPAhigh efficiency particulate air3.3.2 MSDSmaterial safety data sheet(s)3.3.3 PPEpersonal protective equipment3.3.4 UNPunbound engineered nanoscale particles4. Summary of Guide4.1 This Guide presents the elements of an UNP handlingand exposur
39、e minimization program including considerationsand guidance, based on a consensus of viewpoints, for estab-lishing such a program. The six principal elements are: (a)establishing management commitment to the control principle;(b) identifying and communicating potential hazards; (c) as-sessing potent
40、ial UNP exposures within the worksite; (d)identifying and implementing engineering, and administrativecontrols consistent with the control principle for all relevantoperations and activities; (e) documentation; and (f) periodi-cally reviewing its adequacy.4.2 The Control PrincipleExposure control gu
41、idance inthis Guide is premised on the principle (established in thisguide) that, as a cautionary measure, occupational exposures toUNP should be minimized to levels that are as low as isreasonably practicable. This principle does not refer to aspecific numerical guideline, but to a management objec
42、tive,adopted on a cautionary basis, to guide the user when (a)assessing the site-specific potential for such exposures; (b)establishing and implementing procedures to minimize suchexposures; (c) designing facilities and manufacturing pro-cesses; and (d) providing resources to achieve the objective.A
43、dditional discussion of the application of the control principleis set forth in Annex A1.5. Significance and Use5.1 This Guide is intended for use by entities involved in thehandling of UNP in occupational settings. The Guide covershandling principles and techniques that may be applied, asappropriat
44、e, to the variety of UNP materials and handlingsettings. These settings include research and developmentactivities, material manufacturing, and material use and pro-cessing. The Guide may also be used by entities that receivematerials or articles containing or comprising nanoscale par-ticles fixed u
45、pon or within a matrix (i.e., bound nanoscaleparticles), but whose own processes or use may reasonably beexpected to cause such particles to become unbound.6. Establishing a Program to Implement the ControlPrinciple6.1 Process for Establishing ProgramTo attain the inte-grated effort needed to minimi
46、ze UNP exposures consistentwith the control principle, the user should develop a programthat addresses the efforts in all management, planning andoperational phases of the enterprise to be taken to achieve thatobjective. The principal topics of this Guide outline an iterativeprocess typical of many
47、occupational safety regimes the user ofthis Guide may adopt for the initial establishment and imple-mentation of an effective program to minimize occupationalUNP exposures.6.2 Management CommitmentA formal, written manage-ment policy should be established committing to minimizingpotential occupation
48、al UNP exposures to levels that are as lowas is reasonably practicable. The policy and commitmentshould be regularly communicated throughout the organizationand reflected in (a) written administrative procedures, instruc-tions and training materials for operations and contingenciespotentially involv
49、ing occupational UNP exposures, (b) facili-ties design, and (c) instructions to designers, vendors and userpersonnel specifying or reviewing facility design, systems,operations or equipment.6.3 Organization of Personnel and ResponsibilitiesResponsibility and authority for implementing a minimizationprogram consistent with this Guide should be assigned to anindividual with organizational freedom to ensure appropriatedevelopment and implementation of the program. This pro-gram manager would be responsible for coordinating effortsamong the several funct
