Widespread presence of synthetic chemicals throughout the natural environment, both abiotic and biotic, including humans, is a fact, and improved analytical techniques now demonstrate the presence of mixtures of hundreds, if not thousands, of synthetic chemicals and their transformation products in the environment. For most of these chemicals, data on their effects on humans, animals, or plants are missing. For the roughly 24 000 chemicals registered under REACh, for instance, the European Chemicals Agency recently reported that 88% of the dossiers reviewed in 2020 were incomplete, particularly with respect to long-term effects. Conversely, several prominent legacy compounds, such as polychlorinated biphenyls, phthalates, or PFOA, have been intensely investigated and have been shown to affect multiple life functions, including reproduction. Accordingly, the chemical pollution problem is being considered as one of nine planetary boundary threats, yet the least well understood.