The Federal LCA Commons Elementary Flow List: Background, Approach, Description and Recommendations for Use
Edelen, A., T. Hottle, S. Cashman, AND W. Ingwersen. The Federal LCA Commons Elementary Flow List: Background, Approach, Description and Recommendations for Use. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-19/092, 2019.
This report describes the background and creation of a comprehensive list of resources and emissions in the standard life cycle assessment data type of elementary flows called the Federal LCA Commons Elementary Flow List. It was created to serve as a foundational data component for use by Federal agencies and others that are sharing LCA data via the Federal LCA Commons data portal. The list may also be used more broadly by LCA practitioners. This report is intended by all those interested in using the Federal LCA Commons Elementary Flow List.
Elementary flows are a foundational component of the life cycle assessment data model, used to represent resources and emissions that are used or released in human and industrial activities. They enable the development of life cycle inventories and the subsequent application of life cycle impact assessment methods to model potential impacts associated with product systems. This report describes the development of a standardized elementary flow list (FEDEFL) for the Federal LCA Commons. Introduction and Background sections describe relevant history of elementary flows in life cycle data, the purpose of a FEDEFL, and a technical background on elementary flows. An Approach section describes the steps toward creating the FEDEFL and mapping files to convert flows from other sources to FEDEFL flows. It includes the definition of flow classes and flow components - flowables, contexts, and units - and describes the assembly of the components into a flow list using a new Python package, fedelemflowlist. fedelemflowlist also provides the FEDEFL and mappings to Python users and creates a version of the list for use in openLCA software. A brief summary of the resulting v1.0 of the FEDEFL is provided in a Summary section, followed by general and flow class specific Recommendations for Use. Flows are anticipated to be regularly added to the FEDEFL to cover emerging life cycle data needs, and its functionality periodically enhanced as LCA modeling needs and capabilities continue to evolve. A system for updating the FEDEFL has been developed through GitHub and is described in Future Work and Contributing. Related files and resources including the FEDEFL on the Federal LCA Commons, the fedelemflowlist package and associated Wiki, and documentation of usage of the mapping files in openLCA software, are briefly described and links are provided. The FEDEFL will play a critical role in enabling interoperability between life cycle datasets created by federal agencies and can also serve as a standard for elementary flows for a broader community.