This podcast episode explores the creation and impact of symbols used to communicate danger and warn people about hazardous substances. It begins with the introduction of Mr. Yuk, a famous symbol for poison prevention. The episode delves into the history of poison control centers and the rise of dangerous household products in the United States. It also discusses the challenges faced by Mr. Yuk, including the emergence of rival mascots and the decline of recognition over time. The podcast then transitions to the challenges of designing a warning marker for nuclear waste and the importance of communicating danger across vast time frames. The episode concludes with a discussion on the limitations of symbols and the need to address current issues of nuclear waste contamination.