A comprehensive review of used electrical and electronic equipment management with a focus on the circular economy-based policy-making

In recent years, technological advancements have resulted in a proliferation of electrical and electronic equipment (EEE), accompanied by a rising massive amount of used electrical and electronic equipment (UEEE). Studies show that if transboundary flows of UEEE are carried out illegally, it can be one of the reasons for the increase in the volume of waste electrical and electronic equipment (WEEE) in developing countries, which necessitates urgent attention to the management of UEEE and WEEE. Toxic chemical components of WEEE can negatively impact ecosystems and human health and pose a severe threat to accomplishing sustainable development goals (SDGs). This review article provides an in-depth survey of UEEE and its differences from WEEE. UEEE is examined in detail to determine whether it is a potential toxic threat or a valuable source. If the transboundary flows of UEEE occur under legal regulations, it is a step toward a circular economy (CE), and the UEEE is recognized as a valuable resource. Otherwise, it is a potential threat to developing countries. Furthermore, the UEEE and WEEE are assessed from the perspective of international law, particularly the transboundary movement guidelines. In the following, the challenges in the transboundary flows of UEEE from developed to developing countries are mentioned. These challenges include a lack of inventory data, weak waste management policies and laws, expansion of the informal sector, and weak monitoring by law enforcement agencies for reliable environmental management. Finally, solutions to current challenges are presented. Undoubtedly, proper global management and legislation of UEEE and WEEE can help reduce the risks of e-waste and be the most effective way to achieve sustainable development goals.