USEtox 1.01 and 2.01 are relatively consistent in identifying the substances with largest impact potentials. Metals were identified as a priority group of substances for both human toxicity and ecotoxicity. Zinc is a major contributor to the human toxicity impact potential, in both model versions. Zinc’s dominance concerning human toxicity sharply contrasts results from other studies: this is somewhat of a paradox. Using the mass of chemical emissions as a simplified indicator pinpoints somewhat different substances.