Halogens such as chlorine and fluorine are highly reactive and, in some cases, toxic—yet they are also an everyday part of our lives when incorporated into compounds and materials: they are used in toothpaste, Teflon pans, and swimming pools. At the same time, chlorine is one of the most important basic chemicals in the chemical industry, with annual production reaching around 100 million tons—a process that consumes vast amounts of electricity. Einstein Professor Sebastian Hasenstab-Riedel, Professor of Inorganic Chemistry at Freie Universität Berlin, explains in the podcast the opportunities and environmental challenges—particularly those associated with fluorinated compounds—and how his team is working on safe alternatives and new storage technologies. Chemistry as the key to greater sustainability? Yes—with a lot of research!