LCA Process (review) Define Scope Inventory Analysis Impact Analysis Feedback Improvement Analysis Manufacture RERP Where RERP is the “Environmentally Responsible Product Rating”

Improvement Analysis (Interpretation) Life Cycle Interpretation is the phase in which the results of the study and all choices and assumptions made during its course are evaluated in terms of soundness and robustness, and overall conclusions are drawn and recommendations made. ISO14044 distinguishes between three different elements: Identification of significant issues based on LCI and LCIA results Completeness, sensitivity and consistency checks Conclusions, limitation and recommendations One of the main aims of Interpretation is to check the results of Inventory Analysis and Impact assessment against the Goal and Scope Definition of the study.

Identification of significant issues based on LCI and LCIA results Significant inventory data such as energy, emissions, waste, etc. Significant impact categories such as resource use, climate change, toxicity, etc. Significant contribution from life cycle stages such as individual unit processes or whole process groups (e.g. use phase) 10.3 % 4.3 % 85.3 % 0.1 % Typical life cycle GHG emissions of an ICE passenger car

Completeness, sensitivity and consistency checks Completeness check makes sure that nothing important or relevant has been left out (e.g. through cut-off, data gaps or missing impact category). Relevance of missing elements with respect to goal and scope of study needs to be discussed Sensitivity and uncertainty analysis studies the effect of variations in process data, boundary, allocation and modeling choices and other variables. The objective is to assess the reliability and robustness of the LCI and CLIA results. Consistency check determines whether the assumptions, methods, models and data are consistent with goal and scope of the LCA study and with each other. Examples are consistency in - data quality along a product life cycle or between different product systems - regional and temporal aspects - allocation rules and system boundaries - impact assessment

Conclusions, limitation and recommendations Conclusions are based on the significant findings and their robustness. Limitations are based the completeness, sensitivity and consistency checks. Recommendations are based on the conclusions and their limitations. ISO 14044 also provides guidelines on how to report on LCA studies how to conduct a critical review of an LCA study Critical reviews by external experts or panels on interested parties are especially important if the LCA study is intended to be used for a comparative assertion intended to be disclosed to the public.

Case study: Disposable versus reusable diapers Background: When Proctor & Gamble (P&G) launched Pampers disposable diapers in the 1960s, it was considered to be the product breakthrough of the decade. By the early 1990s, Pampers contributed over 18% to the company’s annual revenues. It also became a symbol of the ‘throw-away’ society and was targeted by NGOs. To deflect criticism, P&G commissioned Arthur D. Little to conduct a Life Cycle Assessment of both types of diapers to settle the debate. The Life Cycle Assessment: Arthur D. Little researchers started by defining a functional unit and the resulting reference flows. They made the following simplifying assumption The number of daily diaper changes is the same for both types of diapers. Based on the reference flows life cycle inventories for both product systems were calculated. The following assumption was made: 90% of all reusable diapers are laundered at home. Source: World Resources Institute, 1994

Case study: Disposable versus reusable diapers Raw cotton Cotton fabric Reusable diaper Diaper use Diaper laundry Diaper landfill Other materials Pulp and paper 43% Absorbent gel 27% LDPE film PP fabric Disposable diaper Diaper use Diaper landfill Tapes, elastics, adhesives 23% 7% Source: World Resources Institute, 1994

Case study: Disposable versus reusable diapers Functional unit: Weekly diaper needs Source: World Resources Institute, 1994

Case study: Disposable versus reusable diapers This graph compares data from two different sources: Allen et al. (1992) which report data from a Franklin Associates Study (1992) and the World Resources Institute (WRI, 1994) which reports data from the Arthur D. Little study (1990):

Case study: Disposable versus reusable diapers The results from Allen et al. are mostly higher than those from the WRI, up to a factor of 6. The differences between disposable and reusable diapers are smaller in the Allen et al. results compared to the WRI results. However, the general direction of the results are identical: Reusable diapers consume more energy and more water consume less raw materials generate more emissions to air and water generate less waste Summary: Many environmental choices are about trade-offs between different types of burdens Without impact assessment these burdens are very difficult to compare Without common methodology LCA results are very difficult to reproduce LCA results without comprehensive documentation are not very useful LCA methodology has come a long way since the early 1990s

Life Cycle Assessment of Disposable and Reusable Nappies in the UK (UK’s EPA) Commissioner: Environmental Resources Management (Simon Aumônier, Michael Collins) LCA practitioner: Goal: Compile life cycle inventory and compare potential environmental impacts of production, use and disposal of reusable and disposable nappies Scope: Temporal coverage: 2001-2002 Allocation: Physical relationship, economic for retail energy use Cut-off: Capital equipment and human labor excluded

Life Cycle Assessment of Disposable and Reusable Nappies in the UK Functional unit: The use of nappies during the first 2.5 years of a child’s life, in the UK, for the period 2001-2002 Reference flows: 4.16 disposable nappies of 44.6g daily over 2.5 years 47.5 reusable nappies Impact categories: CML 2000 mid-point indicators global warming • ozone depletion • photo-oxidant formation • depletion of abiotic resources • eutrophication • acidification • human, aquatic and terrestrial toxicity

Process flow diagram disposable nappies

Process flow diagram home laundered reusable nappies

Process flow diagram commercially laundered reusable nappies

Life Cycle Assessment of Disposable and Reusable Nappies in the UK Home laundered reusable Commercially laundered reusable Abiotic resource depletion (kg Sb eq) 4.82 4.09 5.76 Acidification (kg SO2 eq) 3.78 3.13 3.05 Eutrophication (kg PO4 eq) 0.338 0.334 0.275 Global warming (GWP100) (kg CO2 eq) 626 559 762 Ozone layer depletion (ODP) (kg CFC-11 eq) 0.000261 0.00004 0.00008 Photochemical oxidation (kg C2H2) 0.174 0.048 0.049 Human toxicity (kg 1,4-DB eq) 49.4 132 123 Fresh water aquatic ecotox. (kg 1,4-DB eq) 7.01 11.4 11.6 Terrestrial. ecotoxicity (kg 1,4-DB eq) 1.92 1.53 2.7

Life Cycle Assessment of Disposable and Reusable Nappies in the UK Normalization factor: Total estimated impact of Western Europe in 1995

Life Cycle Assessment of Disposable and Reusable Nappies in the UK Sensitivity Analysis Number of changes Excreta as putrescible waste Omitted materials Equivalent COD and BOD emissions Percentage of tumble drying Average age of washing machines Number of reusable nappies

Life Cycle Assessment of Disposable and Reusable Nappies in the UK Conclusions There is no significant difference between any of the environmental impacts of the disposable, home use reusable and commercial laundry systems that were assessed. Main sources of environmental impact: Disposables: Reusables: Raw material production and conversion of nappy components Fuels and electricity used in washing and drying Waste management: No substantial contribution to total impact Main opportunities for improvement: Disposables: Reusables: Mass reduction and improved materials manufacturing Increase energy efficiency of washing and drying

The Use of Life Cycle Assessments LCA: Goal & Scope Life Cycle Inventory Impact Assessment Interpretation Who are the users? What are the uses?

The Users of Life Cycle Assessments Companies: Especially in Scandinavian countries, Japan, Holland, Germany, Switzerland (e.g. Volvo, Electrolux, Honda, Toyota, Proctor & Gamble, Unilever, Corus, Arcelor, Alcan, etc.) Through in-house experts, LCA consultancies or universities. Trade associations: Especially for material commodities (e.g. plastics, steel, aluminum, concrete, etc.) Through the experts of their member companies, LCA consultancies or universities. NGOs: Mostly commissioned to external LCA consultancies or universities. Government agencies: Especially in Scandinavian countries, Japan, Holland, Germany, Switzerland, EU Through in-house experts, LCA consultancies or universities. Business analysts: Typically analyze externally created LCA information on businesses and sectors.

The Uses of Life Cycle Assessments Companies: Originally intended for external use, e.g. marketing. However, currently mainly for internal use due to bad initial experiences of external uses. Currently mainly retrospective and for learning proposes, instead of prospective use for decision making purposes. Currently, decisions based on LCA results are more operational than strategic. Trade associations: Trade associations of material commodities producers more frequently use LCA for external purposes (e.g. marketing, as lobbying tool in the policy process). NGOs: To create scientific foundations of campaigns or investigate claims by industry. Government agencies: To analyze and design environmental policies and regulations (especially by the EPAs of European countries). EUs Integrated Product Policy recommends LCA. Business analysts: To analyze and rate individual companies and industry sectors.

Internal vs. external use of Life Cycle Assessments Most companies currently use LCA for internal purposes. Internal uses are: Hotspot analysis of existing or planed products Compare existing products with products under development Product/process design (short-term, operational) Product/process development (long-term, strategic) As LCA methodology matures, so do the number and frequency of external uses . External uses are: Marketing, especially final product comparisons (credibility and complexity issues) Lobbying, especially commodity comparisons Providing information and education to customers and other stakeholders Eco-labeling (also called environmental product declarations – EPDs)