Waste audit methods and techniques: International experience and implications for Vietnam

Environmental audit (EA) is an effective management tool, applied by many countries and stipulated in Vietnam's Law on Environmental Protection (2020).EA provides information on the current state of the environment, aiding assessment and decision-making.Among these, waste audit (WA) is an important type, helping businesses determine the amount of solid waste generated, thereby proposing recycling solutions, optimising resources, and enhancing production efficiency.However, currently, WA mainly focuses on processes, lacking specific guidance on implementation methods and techniques.This study synthesises WA experiences from other countries and proposes their application in Vietnam.The results indicate two approaches: top-down and bottom-up.The top-down approach (using LCA, MFA models) is suitable for sectoral and inter-sectoral audits.Meanwhile, the bottom-up approach (onsite emission inventory, material balance, field monitoring) is suitable for production and service facilities.Depending on data availability and output requirements, the auditing unit can select appropriate methods and techniques.The flexible application of these methods will enhance WA efficiency, contributing to sustainable waste management.