This document defines product category rules (PCR) for electronic and electrical products and systems (EEPS). It specifies the process and requirements on how to conduct life cycle assessment(LCA) in the context of environmental declarations. PCR is complemented by additional product-specific rules (PSR), which further define e.g. functional units and default scenarios in the product-specific context. Therefore, it also provides guidance on how to develop PSR in corresponding technical committees. This document provides common rules for: a) LCA, including the requirements for developing default scenarios; b) the LCA report; c) the development of PSRs. This document provides further guidelines for environmental declarations. The LCA principles and framework are based on the ISO 14040 series of standards (i.e., ISO 14040 and ISO 14044), and therefore out of scope of this standard.