Yale professor Paul Anastas explains dose-response curves as part of the toxicology module in his Introduction to Green Chemistry course. He lays out the molecular basis of chemical hazard and walks through how toxicologists relate the amount of a substance an organism receives to the severity of biological effect, the core logic behind concepts like LD50 and threshold versus non-threshold responses. The lecture builds on earlier material introducing basic toxicity concepts, framing dose-response as a foundational tool for evaluating whether a chemical is hazardous and at what exposure level. It fits within the course's broader argument that chemists need to understand toxicology to design safer molecules from the outset rather than treating hazard as an afterthought. Aimed at students with some chemistry background, the video is short and focused, using the dose-response curve as its central teaching device.