For each chemical you have reported, check all the physical and health hazard boxes that apply.
These hazard categories are defined in 40 CFR 370.66. The physical and health hazards are defined in the OSHA Hazard Communication Standard, 29 CFR 1910.1200, which EPA has adopted in a Federal Register notice on June 13, 2016 (81 FR 38104). See also the correction notice published on July 22, 2016 (81 FR 47311).
These Federal Register notices and the fact sheet are available online: https://www.epa.gov/epcra/epcra-non-section-313-amendments-and-guidance#technical amendment