Comparison of type III environmental product declarations for construction products: Material sourcing and harmonization evaluation

Environmental Product Declarations (EPDs) are third-party verified product data sheets developed based on the requirements of ISO 14025, and are governed by Product Category Rules (PCRs) - documents developed by “Program Operators” responsible for both rule creation and third-party verification. Together, these documents are intended to provide consistent, complete, transparent, and trustworthy material information, appropriate to inform decision making based on product environmental performance. Despite this intention, a detailed study of 50 Environmental Product Declarations and their underlying 13 Product Category Rules across three categories: insulation, flooring, and cladding, and showed that 38% of Environmental Product Declarations were missing information required by the ISO standard and 8% contained self-contradictory information. Further, the lack of harmonization between and poor quality of several underlying Product Category Rules limited the comparability between Environmental Product Declarations in the same categories (ranging from 1 to 24%) and even between those written to the same Product Category Rules (8-83%). This paper investigates the common errors and omissions in these documents that result in this poor harmonization and presents a discussion of the systemic issues arising from unregulated Product Category Rule development. In light of this investigation, specific actions are proposed to improve both overall Environmental Product Declaration quality and facilitate harmonization efforts.