Submitted Comment Name Chantal Lavigne Affiliation Vertima Subject Comments to Embodied Carbon Reporting Technical Meeting October 30, 2025 Message First of all, thank you very much for the opportunity to comment on your program. Comments below should be read as shared thoughts and not a judgement on the work done. Definitions For clarity, examples or definitions should be added to the following: - Primary impact results (definition is needed) - Contracted purchases (how is this defined) - Renewable energy (they should be named to confirm which energy source is considered renewable) - Low carbon fuels (they should be named or defined to confirm which fuel is considered low carbon) - Percentage of primary data used to estimate GWP (provide example and/or definition) Allocation - According to ISO 14044, allocation shall be dealt with according to a stepwise approach: 1) Allocation should be avoided if possible; 2) When allocation cannot be avoided, the inputs/outputs of the system should follow an allocation that reflects the underlying physical relationships; 3) When physical relationships cannot be established, other relationships should be used. This includes economic allocation. - As economic allocation should be used as a last resort, clarification regarding the use of potential environmental impact results obtained with economic allocation should be put forward, as well as the goal it is thought to achieve. - Presenting potential environmental impact results obtained with economic allocation in an EPD will bring additional complexity in understanding the EPD results. This should be considered before requesting potential environmental impact results obtained with economic allocation to be presented in an EPD. Emission factors A reference to a list of available emission factors and how they were determined would improve the clarity of the document and how the goal is fulfilled. Using fixed emission factors for raw materials reduces the opportunity for manufacturers to work with their suppliers to reduce the embodied carbon of their products. Knowing that, for some manufacturers, A1 is the life cycle stage with the most contribution to potential environmental impacts, obtaining an important reduction in embodied carbon will not be possible without the collaboration of suppliers. In the event fixed emission factors are maintained, will they be updated on a regular basis? At which frequency? Confidentiality EPDs are based on LCAs and the details of the LCAs are presented in project reports (not public) as requested by PCRs/ISO 21930:2017. The limit to transparency in the EPD is data confidentiality. Too much transparency on the LCA model, for example, could cause prejudice to the manufacturer. Please consider this type of situation in the EPD approach and associated reporting requirements (CARB method 1). Uncertainty EPDs are based on LCA models. With every model comes choices, such as, for example, choosing LCI datasets to best represent raw materials needed to produce a product. The choice of the LCI dataset (or EPD) varies from practitioner to practitioner, database to database, and over time as new data becomes available. The choice of the LCI dataset is made to obtain the best possible temporal, geographical, technological representativeness of the product. This is part of the comparability problem as you mentioned, but it is also part of the nature of LCAs for EPDs in trying to represent the studied product as best as possible. Instead of using fixed emission factors per raw material and limiting the flexibility of LCAs for EPDs, it would be interesting to work with estimated uncertainty values associated to model choices. This would also have the advantage of increasing the EPD user awareness of EPD uncertainty. Age of primary data and update frequency As already mentioned by others, requesting data no more than 2 years old and updating the third-party verified EPD, change or no change in the product A1-A3, every two years is challenging cost-wise and time wise. A simplified process would be appreciated and help implement the process. Generally speaking, most EPDs updates tend toward GWP reduction over time and not the opposite. A lack of EPD update before the 5 year expiration date could potentially be considered as a conservative approach for some materials. Thank you for your consideration. Chantal Lavigne, LCA & Human Health Management Lead Vertima File Upload (i.e., Attachments): N/A N/A
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