Ten global chemical companies and stakeholders have released guidance for the chemical sector on communicating a product’s environmental footprint using life cycle assessment (LCA) methods. Collaborating as a working group of the World Business Council for Sustainable Development (WBCSD), the members developed the guidance document – titled Life Cycle Metrics for Chemical Products – with the objective of facilitating “improved sustainability across value chains” by communicating reliable information using a “common language.” The guidance is based on ISO 14040:2006 and 14044:2006 and sets out requirements covering topics including:
- Footprint system boundaries: Product footprint studies should be cradle-to-grave, except for business-to-business products, which may use cradle-to-gate studies. Cradle-to-gate studies must include end-of-life impacts for all waste generated in production.
- Defining the functional unit and reference flow: The functional unit must be consistent with the goal and scope of the study, and the duration of the functional unit must be specified for cradle-to-grave studies. Compared solutions shall be assessed on main functionality, technical quality (stability, durability, ease of maintenance), and additional functions rendered during use and disposal.
- Impact categories, energy, and other flows: The guidance names certain models to use in characterizing impacts ranging from global warming to marine eutrophication to human toxicity and ecotoxicity. Energy flows, including cumulative energy demand, renewable energy consumption, and non-renewable energy consumption, must also be assessed and reported.
- Data source requirements and quality management: Primary data (from specific operations in the studied product’s life cycle) should be “the most accurate available data,” including on-site measurements of aggregated consumed water, energy, and raw material, as well as continual air and water emissions.
- Main methodological choices: The guidance provides a decision tree for choosing how to allocate environmental impacts for multiple products with different functions coming from the same system. Other methodological choices addressed include: attribution of recycling benefits; avoided emissions; bio-based carbon storage; carbon storage and delayed emissions; and land-use change.
- Uncertainties of results: At a minimum, studies should include a qualitative description of uncertainties. Quantitative assessments of uncertainty based on Monte Carle simulations are optional.
- Critical/peer review: Chemical product footprint studies must undergo peer review to assess consistency with the guidance. Externally published comparative claims must undergo “an external critical review by a panel of LCA experts.” All studies must include a statement specifying that the study was critically or peer reviewed and summarizing the review’s conclusions.
This guide is the third release from the WBCSD Chemical Sector’s “Reaching Full Potential” project, which previously released guidance for the chemical industry on accounting and reporting corporate greenhouse gas emissions and avoided emissions. Together, the Project’s publications seek to provide for “consistent and credible communication on how the value chains of chemicals impact on and contribute to sustainability.”
The working group is comprised of major companies like BASF, Eastman Chemical, Evonik, and Solvay, as well as Cefic, the European Chemical Industry Council. The next step for the Reaching Full Potential project is to develop a guide for companies to assess social impacts and benefits of chemical products. Development of that guide is already under way, with release expected in late 2015.