ASQ ISO 14040-1997 Environmental management - Life cycle assessment - Principles and framework.pdf

1、ANSI/ISO 14040-1997AMERICAN NATIONAL STANDARDEnvironmental management Life cycle assessment Principles and frameworkAMERICAN SOCIETY FOR QUALITYP.O. BOX 3005MILWAUKEE, WI 53201-3005ANSI/ISO 14040-1997AMERICAN NATIONAL STANDARDEnvironmental managementLife cycle assessment Principles and frameworkAppr

2、oved as an American National Standard by:NSF International (NSF)American Society for Testing - evaluating the potential environmental impacts associated with those inputs and outputs ;- interpreting the results of the inventory analysis and impact assessment phases in relation to theobjectives of th

3、e study.LCA studies the environmental aspects and potential impacts throughout a products life (i.e. cradle-to-grave) from raw material acquisition through production, use and disposal. The general categories ofenvironmental impacts needing consideration include resource use, human health, and ecolo

4、gicalconsequences.LCA can assist in- identifying opportunities to improve the environmental aspects of products at various points in theirlife cycle ;- decision-making in industry, governmental or non-governmental organizations (e.g. strategicplanning, priority setting, product or process design or

5、redesign) ;- selection of relevant indicators of environmental performance, including measurement techniques ;and- marketing (e.g. an environmental claim, ecolabelling scheme or environmental product declaration).This International Standard recognizes that LCA is still at an early stage of developme

6、nt. Some phasesof the LCA technique, such as impact assessment, are still in relative infancy. Considerable workremains to be done and practical experience gained in order to further develop the level of LCA practice.Therefore, it is important that the results of LCA be interpreted and applied appro

7、priately.If LCA is to be successful in supporting environmental understanding of products, it is essential that LCAmaintains its technical credibility while providing flexibility, practicality and cost effectiveness ofapplication. This is particularly true if LCA is to be applied within small- and m

8、edium-sized enterprises.1)In this International Standard, the term “product“ used alone not only includes product systems but can also include servicesystems.2)An inventory may include environmental aspects which are not directly related to the inputs and outputs of the system.ANSI/ISO 14040-1997viT

9、he scope, boundaries and level of detail of an LCA study depend on the subject and intended use ofthe study. The depth and breadth of LCA studies may differ considerably depending on the goal of aparticular LCA study. However, in all cases, the principles and framework established in thisInternation

10、al Standard should be followed.LCA is one of several environmental management techniques (e.g. risk assessment, environmentalperformance evaluation, environmental auditing, and environmental impact assessment) and may not bethe most appropriate technique to use in all situations. LCA typically does

11、not address the economic orsocial aspects of a product.Because all techniques have limitations, it is important to understand those that are present in LCA. Thelimitations include the following.- The nature of choices and assumptions made in LCA (e.g. system boundary setting, selection ofdata source

12、s and impact categories) may be subjective.- Models used for inventory analysis or to assess environmental impacts are limited by theirassumptions, and may not be available for all potential impacts or applications.- Results of LCA studies focused on global and regional issues may not be appropriate

13、 for localapplications, i.e. local conditions might not be adequately represented by regional or globalconditions.- The accuracy of LCA studies may be limited by accessibility or availability of relevant data, or bydata quality, e.g. gaps, types of data, aggregation, average, site-specific.- The lac

14、k of spatial and temporal dimensions in the inventory data used for impact assessmentintroduces uncertainty in impact results. This uncertainty varies with the spatial and temporalcharacteristics of each impact category.Generally, the information developed in an LCA study should be used as part of a

15、 much morecomprehensive decision process or used to understand the broad or general trade-offs. Comparingresults of different LCA studies is only possible if the assumptions and context of each study are thesame. These assumptions should also be explicitly stated for reasons of transparency.This Int

16、ernational Standard provides principles and framework and provides some methodologicalrequirements for conducting LCA studies. Additional details regarding methods are provided in thecomplementary International Standards ISO 14041, ISO 14042 and ISO 14043 concerning the variousphases of LCA .This In

17、ternational Standard, like other International Standards, is not intended to be used to create non-tariff trade barriers or to increase or change an organizations legal obligations.ANSI/ISO 14040-19971Environmental management Life cycle assessment Principles andframework1 ScopeThis International Sta

18、ndard specifies the general framework, principles and requirements forconducting and reporting life cycle assessment studies. This International Standard does notdescribe the life cycle assessment technique in detail.2 Normative referenceThe following standard contains provisions which, through refe

19、rence in this text, constituteprovisions of this International Standard. At the time of the publication, the edition indicated wasvalid. All standards are subject to revision, and parties to agreements based on this InternationalStandard are encouraged to investigate the possibility of applying the

20、most recent edition of thestandard indicated below. Members of IEC and ISO maintain registers of currently validInternational Standards.ISO 14041: 3Environmental management - Life cycle assessment - Goal and scopedefinition and life cycle inventory analysis3 DefinitionsFor the purposes of this Inter

21、national Standard, the following definitions apply.3.1allocationpartitioning the input or output flows of a unit process to the product system under study3.2comparative assertionenvironmental claim regarding the superiority or equivalence of one product versus a competingproduct which performs the s

22、ame function3.3elementary flow(1) material or energy entering the system being studied, which has been drawn from theenvironment without previous human transformation(2) material or energy leaving the system being studied, which is discarded into the environmentwithout subsequent human transformatio

23、n3.4environmental aspectelement of an organizations activities, products or services that can interact with the environment3To be published.ANSI/ISO 14040-199723.5functional unitquantified performance of a product system for use as a reference unit in a life cycle assessmentstudy3.6inputmaterial or

24、energy which enters a unit processNOTE : Materials may include raw materials and products.3.7interested partyindividual or group concerned with or affected by the environmental performance of a productsystem, or by the results of the life cycle assessment3.8life cycleconsecutive and interlinked stag

25、es of a product system, from raw material acquisition orgeneration of natural resources to the final disposal3.9life cycle assessmentLCAcompilation and evaluation of the inputs, outputs and the potential environmental impacts of aproduct system throughout its life cycle3.10life cycle impact assessme

26、ntphase of life cycle assessment aimed at understanding and evaluating the magnitude andsignificance of the potential environmental impacts of a product system3.11life cycle interpretationphase of life cycle assessment in which the findings of either the inventory analysis or the impactassessment, o

27、r both, are combined consistent with the defined goal and scope in order to reachconclusions and recommendations3.12life cycle inventory analysisphase of life cycle assessment involving the compilation and quantification of inputs and outputs,for a given product system throughout its life cycle3.13o

28、utputmaterial or energy which leaves a unit processNOTE : Materials may include raw materials, intermediate products, products, emissions and waste.3.14practitionerindividual or group that conducts a life cycle assessmentANSI/ISO 14040-199733.15product systemcollection of materially and energeticall

29、y connected unit processes which performs one or moredefined functionsNOTE : In this International Standard, the term “product“ used alone includes not only product systems butcan also include service systems.3.16raw materialprimary or secondary material that is used to produce a product3.17system b

30、oundaryinterface between a product system and the environment or other product systems3.18transparencyopen, comprehensive and understandable presentation of information3.19unit processsmallest portion of a product system for which data are collected when performing a life cycleassessment3.20wasteany

31、 output from the product system which is disposed of4 General description of LCA4.1 Key features of LCAThe following list summarizes some of the key features of the LCA methodology.- LCA studies should systematically and adequately address the environmental aspects ofproduct systems, from raw materi

32、al acquisition to final disposal.- The depth of detail and time frame of an LCA study may vary to a large extent, depending onthe definition of goal and scope.- The scope, assumptions, description of data quality, methodologies and output of LCA studiesshould be transparent. LCA studies should discu

33、ss and document the data sources, and beclearly and appropriately communicated.- Provisions should be made, depending on the intended application of the LCA study, torespect confidentiality and proprietary matters.- LCA methodology should be amenable to the inclusion of new scientific findings andim

34、provements in the state-of-the-art of the technology.- Specific requirements are applied to LCA studies which are used to make a comparativeassertion that is disclosed to the public.ANSI/ISO 14040-19974- There is no scientific basis for reducing LCA results to a single overall score or number, since

35、trade-offs and complexities exist for the systems analysed at different stages of their life cycle.- There is no single method for conducting LCA studies. Organizations should have flexibility toimplement LCA practically as established in this International Standard, based upon thespecific applicati

36、on and the requirements of the user.4.2 Phases of an LCALife cycle assessment shall include definition of goal and scope, inventory analysis, impactassessment and interpretation of results, as illustrated in figure 1.LCA results may be useful inputs to a variety of decision-making processes. Applica

37、tions of LCAsuch as the examples listed in figure 1 are outside the scope of this International Standard.Life cycle inventory studies shall include definition of goal and scope, inventory analysis andinterpretation of results. The requirements and recommendations of this International Standard,with

38、the exception of those provisions regarding impact assessment, also apply to life cycleinventory studies.Goaldefinitionand scopeInventoryanalysisImpactassessmentInterpretationLife cycle assessment frameworkDirect applications :- Product development- Marketingand improvement- Strategic planning- Othe

39、r- Public policy makingFigure 1 : Phases of an LCA5 Methodological frameworkIn addition to the general requirements specified below, it is a requirement of this InternationalStandard that the definition of goal and scope and the inventory comply with the respectiveprovisions of ISO 14041.ANSI/ISO 14

40、040-199755.1 Definition of goal and scopeThe goal and scope of an LCA study shall be clearly defined and consistent with the intendedapplication.5.1.1 Goal of the studyThe goal of an LCA study shall unambiguously state the intended application, the reasons forcarrying out the study and the intended

41、audience, i.e. to whom the results of the study areintended to be communicated.5.1.2 Scope of the studyIn defining the scope of an LCA study, the following items shall be considered and clearlydescribed :- the functions of the product system, or, in the case of comparative studies, the systems ;- th

42、e functional unit ;- the product system to be studied ;- the product system boundaries ;- allocation procedures ;- types of impact and methodology of impact assessment, and subsequent interpretation to beused ;- data requirements ;- assumptions ;- limitations ;- initial data quality requirements ;-

43、type of critical review, if any ;- type and format of the report required for the study.The scope should be sufficiently well defined to ensure that the breadth, the depth and the detailof the study are compatible and sufficient to address the stated goal.LCA is an iterative technique. Therefore, th

44、e scope of the study may need to be modified while thestudy is being conducted as additional information is collected.5.1.2.1 Function and functional unitThe scope of an LCA study shall clearly specify the functions of the system being studied. Afunctional unit is a measure of the performance of the

45、 functional outputs of the product system.The primary purpose of a functional unit is to provide a reference to which the inputs and outputsare related. This reference is necessary to ensure comparability of LCA results. Comparability ofLCA results is particularly critical when different systems are

46、 being assessed to ensure that suchcomparisons are made on a common basis.A system may have a number of possible functions and the one selected for a study is dependenton the goals and scope of the study. The related functional unit shall be defined and measurable.EXAMPLE : The functional unit for a

47、 paint system may be defined as the unit surface protected for aspecified time period.ANSI/ISO 14040-199765.1.2.2 System boundariesThe system boundaries determine which unit processes shall be included within the LCA.Several factors determine the system boundaries, including the intended application

48、 of the study,the assumptions made, cut-off criteria, data and cost constraints, and the intended audience.The selection of inputs and outputs, the level of aggregation within a data category, and themodelling of the system shall be consistent with the goal of the study. The system should bemodelled

49、 in such a manner that inputs and outputs at its boundaries are elementary flows.The criteria used in establishing the system boundaries shall be identified and justified in thescope of the study. LCA studies used to make a comparative assertion that is disclosed to thepublic shall perform an analysis of material and energy flows to determine their inclusion in thescope of the study.5.1.2.3 Data quality requirementsData quality requirements specify in general terms the characteristics of the data needed for thestudy. Data quality requirements shall be defined to enable the goals an