This action proposes to revise EPA's definition of Volatile Organic Compounds (VOC) for purposes of preparing State Implementation Plans (SIPs) to attain the National Ambient Air Quality Standards (NAAQS) for ozone. The action would add (Z)-1-Chloro2,3,3,3,-Tetrafluoropropene (also known as HCFO-1224yd (Z); CAS # 111512-60-8) to the list of compounds excluded from the definition of VOC on the basis that this compound makes a negligible contribution to tropospheric ozone formation. VOC exemption petition submitted by AGC Chemicals Americas, Inc., on July 29, 2020. This compound is not a hazardous air pollutant and is not a stratospheric ozone depleting substance. It has low global warming potential compared to other compounds which it is substituting.