The Stockholm Convention was signed in 2001 to protect humans and the environment from POPs . An EU Legislation regulation (EC No 850/2004) was adopted later to implement the Convention in the EU . Initially, the Convention regulated 12 POPs or groups of POPs such as aldrin, chlordane and dichlorodiphenyltrichloroethane (DDT). Over time, the list expanded to include 39 substances and substance groups as of January 2024, with the regulation covering the manufacturing, sales, use, and waste management of these chemicals, as well as unintentional releases in some cases . Structural similarity and the resulting similar compound properties played a major role in managing the grouping of substances under the Convention, for instance, polychlorinated biphenyls (PCBs), dioxins and DDT derivatives .