Water is becoming increasingly contaminated with substances considered persistent, mobile and toxic (PMT) or very persistent and very mobile (vPvM). Increasing regulatory action has been introduced to address the substantial impact of such substances, including several per- and polyfluoroalkyl substances (PFAS), melamine and 1,4-dioxane. New hazard classes for PMT/vPvM substances have been proposed for implementation in the European regulation for the classification, labelling and packaging of substances and mixtures (CLP Regulation). Ultimately, preventing the emissions and exposure of PMT/vPvM substances is the best way to ensure zero pollution from them. The development of PMT/vPvM substances as a hazard class, and pathways to reduce their exposure, will be presented.