This final rule, issued pursuant to the Toxic Substances Control Act (TSCA) and the TSCA Health and Safety Data Reporting rule, requires manufacturers (including importers) of 50 specified chemical substances to report certain lists and copies of unpublished health and safety studies to EPA. The chemical substances subject to this rule are listed in this document and consist of the 20 designated by EPA as High-Priority Substances and the 30 organohalogen flame retardants being evaluated for risks by the Consumer Product Safety Commission (CPSC) under the Federal Hazardous Substances Act (FHSA). EPA is taking this action because the TSCA Interagency Testing Committee (ITC) added these chemical substances to the Priority Testing List through its 69th and 74th Reports and EPA will use this information to inform the risk evaluations currently underway for 20 High-Priority Substances and for future prioritization.