To keep swimming pool water clean and clear, consumers purchase, transport, store, use, and dispose of large amounts of potentially hazardous chemicals. Data about incidents due to the use of these chemicals and the resultant public health impacts are limited. The authors analyzed pool chemical release data from 17 states that participated in the Agency for Toxic Substances and Disease Registry’s chemical event surveillance system during 2001–2009. In 400 pool chemical incidents, 60% resulted in injuries. Of the 732 injured persons, 67% were members of the public and 50% were under 18 years old. Incidents occurred most frequently in private residences (39%), but incidents with the most injured persons (34%) occurred at recreational facilities. Human error (71.9%) was the most frequent primary contributing factor, followed by equipment failure (22.8%). Interventions designed to mitigate the public health impact associated with pool chemical releases should target both private pool owners and public pool operators.