Toolbox for Life Cycle Sustainability Assessment of Products

Life Cycle Assessments (LCA) are predominantly used to evaluate environmental impacts throughout the life cycle of a product or service. Sustainability, however, is a tripod based on environmental, economic, and social issues; which justifies the extension of the application of environmental LCAs by the missing key applications such as Life Cycle Costing (LCC) and Social Life Cycle Assessment (S-LCA). The techniques selected are ISO conform. The frameworks described for each of them present differences and commonalities that are discussed in this paper. Decision making processes are becoming more complex; answers to real problems need multi-criteria assessments. For instance, the assessment of socio-economic impacts of climate change cannot only rely on the application of an S-LCA or LCC. In order to move towards a life cycle sustainability assessment, there is a need to link existing tools. Aiming to contribute to better informed decisions on sustainability aspects of products, and following the advice of the International Life Cycle Board, UNEP and SETAC are developing a toolbox on Life Cycle Sustainability Assessment (LCSA). This proposal has the aim to show the outline of the toolbox under development: selected tools, their commonalities and differences, and a proposal of an integrated LCSA. 1 Life Cycle Sustainability Assessment Life Cycle Sustainability Assessment (LCSA) is a technique to evaluate environmental, social, and economic impacts of a product over its entire life cycle. In the last decade, a number of sustainability assessment approaches, tools and discussion papers have been presented to Governments, academia, experts and agencies for development, addressing national (e.g. the Swiss contribution [1]), regional (e.g. Mattisse project funded by the EU [2]) or sectoral (e.g. proposal for the building sector [3] concerns. The World Bank, for instance, incorporates sustainability criteria in their assessments, however, no systematic quantitative tool is available yet, but a recommendation of principles to be used [4]. The development of all these approaches is a response to the need to evaluate sustainability; nevertheless, few of them are based on life cycle aiming to provide quantitative (and qualitative) results on sustainability aspects for informed decisions on products. Three examples, among others, are the following ones: * the BASF ecoefficiency tool [5], which aims to integrate quantified social indicators into the BASF eco-efficiency analysis, originally addressing environmental concerns; * the Product Sustainability Assessment tool (PROSA) [6], that gives particular attention to the analysis of social and economic aspects, and to the consideration of utility and consumer aspects; * the Sustainability Assessment Model (SAM) [7], a tool for engaging people within organisations in sustainable development thinking and to evaluate the sustainability of projects. Although the former examples given propose indicators and assessment methods, none of them are presented as a tool. Therefore, we propose a toolbox on Life Cycle Sustainability Assessment (LCSA) based on life cycle based techniques which are ISO 14040 conform (ISO, 2006a): environmental LCA (E-LCA), social LCA (S-LCA) and life cycle costing (LCC). The toolbox has been discussed under the UNEP and SETAC Life Cycle Initiative aiming ‘to interlink current LCA tools and provide a triple-bottom-line sustainable development toolbox’ [8]. The aim of this LCSA toolbox is to contribute to better informed decisions on sustainability aspects of products, with impact categories and sub-categories for the three dimensions of sustainability; however without presenting impact assessment methods and interlinkages among the models, but providing recommendations on how to proceed with results obtained. 2 Overview of E-LCA, LCC and S-LCA E-LCA aims to address the environmental dimension in a holistic manner by covering all relevant environmental impacts. Yet, in practice often a smaller subset of the possible and also of the relevant impacts identified by means of a hotspot assessment are taken into account; reasons are 1) to obtain a clearer picture that is easier to communicate, 2) some impacts are hard to grasp and operationalise, as noise, long term emissions, (still) land use, and therefore omitted for practicality reasons. While LCC is a generic method used in industry since about 50 years; a specific approach has been developed to be used in the context of Life Cycle Assessment, called Environmental LCC [9 e 10]. Environmental LCC focuses on the economic dimension and only on microeconomic, real money flows; money flows can be positive (as revenues) or negative (as costs). LCC hotspot assessment can help assess where the cost or benefit are significant in the entire life cycle of products. Other types of economic impacts are not addressed, to avoid double counting and overlap. S-LCA has the focus on social and socio-economic hotspots which are identified in consultation and validated by concerned stakeholders: consumers, local community, workers, value chain actors and the society. Stakeholder involvement is essential to develop S-LCA studies. More specifically, the following topics need to be understood and aligned when combining E-LCA, S-LCA, and LCC (here and in the following always understood as Environmental LCC): 1) Goal and scope definition i) Functional unit: in all three approaches, the product utility should be considered, though in S-LCA a social utility (the utility to other stakeholders, beyond the consumer’s ) may be included; ii) Product system: regarding the modeling structure, while the E-LCA and LCC studies consider the unit processes along the life cycle, the SLCA study adds the organizations that run the processes and the stakeholders; iii) cut-off rules could be different in each of the approaches: while in ELCA, physical, economical or environmental relevance criteria might be used, in S-LCA, a socio-economical criteria is used (working-hours); in LCC, quite often different processes are relevant for the result, such as research and development processes; therefore, system boundaries need to be equivalent when combining the three approaches, but they will not necessarily be identical. 2) Inventory: i) in E-LCA and LCC, in praxis, only quantitative data is used. The situation is different in S-LCA, where more qualitative and semiquantitative data is used; ii) in E-LCA, validation is performed using mass or energy balances, and by comparing emission factors. In S-LCA, mass and energy balances are not accessible usually; therefore, common model validation techniques, such as triangulation, need to be used.; iii) In E-LCA, time is frequently not taken into account. S-LCA is at an early stage of implementation and applications are static without considering time effects. In LCC time is is often taken into account, and discounting is often applied as well. 3) Impact assessment: i) in E-LCA positive impacts are not defined separately in the impact assessment method. Environmental benefits are understood as the negative value of a given impact. This is different in LCC and S-LCA, where positive impacts can occur (e.g. revenues in LCC and employment creation in S-LCA); ii) In E-LCA all impacts are assumed to be linear.; iii) Regionalization is an important issue in S-LCA and although also relevant for E-LCA, the first impact assessment methods did not include this. iv) Characterization methods are available for some impact categories for E-LCA (although not to all of them as some impacts are hard to grasp and operationalise, as noise, long term emissions, (still) land use); in SLCA, the first impact assessment methods are proposed [11]; in LCC, aggregated costs are already the evaluated impact, therefore an impact asssement methods as such is not necessary. v) In E-LCA weighting of impact categories is an area of discussion. Impact categories can be grouped into 3 or four areas of protection (human health, Ecosystem quality, resources, etc). In many cases, a clear ranking of options can only be obtained if priorities among impact categories are defined. 4) Peer review is recommended for the three tools and is regular praxis for comparisons and public communication. In addition, in S-LCA, stakeholder consultation and involvement is needed before finalizing the critical review statements. 3 A way to implement an LCSA (UNEP, 2010b) 3.1 Goal and Scope Definition in LCSA LCC, S-LCA and E-LCA pursue different overall aims. While the LCC has the aim to provide an indication on costs along the product chain, the E-LCA and SLCA provide findings on environmental and social impacts, correspondingly. The goal of the study is to evaluate the sustainability of two alternatives for heating water to take showers as a support for the product designer. The functional unit chosen was heating 200 liters of water per day of 40 C for a family with 4 people during 20 years in Brazil. Furthermore, the maintainance of products should be ease and for the low class (that is, the initial costs should not be higher than $ 20,00 and the usage costs, $ 20,00/month). Due to the initial investments, only electric shower would be an option, nevertheless considering that each person takes a 5 min shower a day (10 hours / month) and the costs of electricity is of 0,50 $/ kWh, the maximum power of the product is 4000 W. So, the reference flow is a 4000 W showLet us consider that the electric shower life cycle. To assembly consider that the shower demands only 6 types of materials. As there are current LCA databases (although not reflecting Brazilian conditions), it was possible to use a cut-off considering an environmental relevance, which resulted in 2 materials. Nevertheless, while considering the working hours, 1 of these processes was not important, but another 2 processes should be considered. All the chosen materials were also important in costs terms.