Reported emissions from the Fluorinated Chemicals Production sector decreased from 17.3 million metric tons (MMT) CO2e in 2011 to 6.4 MMT CO2e in 2020, a decrease of 63%. This long-term downward trend was driven primarily by increases in voluntary emission controls at facilities (e.g., use of destruction devices) but also by changes in the types and quantities of fluorinated gases produced. The fluctuations seen between 2016 and 2020 were primarily driven by fluctuations in the emission rate from production of chlorodifluoromethane (HCFC-22), which is associated with emissions of trifluoromethane (HFC-23).  Since 2012, emissions from HCFC-22 production and HFC-23 destruction have varied, with a high of 5.2 MMT CO2e in 2017 and a low of 2.2 MMT CO2e in 2020. Because HCFC-22 depletes stratospheric ozone, its production for non-feedstock uses was phased out in 2020 under the U.S. Clean Air Act and the Montreal Protocol on Substances that Deplete the Ozone Layer. However, production of HCFC-22 for use as a feedstock is permitted to continue indefinitely. 
Emissions from production of other fluorochemicals decreased from a high of 9.3 MMT CO2e in 2013 to 4.7 MMT CO2e in 2017. Emissions then increased through 2019 to 5.3 MMT CO2e, and in 2020, these emissions decreased to 4.2 MMT CO2e, a decrease of 21%. This decrease was primarily due to the increased use of emission control technology, although some facilities had lower emissions due to reduced production.
 Trifluoromethane (HFC-23 or CHF3) is generated as a byproduct during the manufacture of chlorodifluoromethane (HCFC-22). HCFC-22 is produced by the reaction of chloroform (CHCl3) and hydrogen fluoride (HF) in the presence of a catalyst, antimony pentachloride (SbCl5). The HFC-23 generated may be released to the atmosphere, recaptured for use in a limited number of applications, or destroyed.
 Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2018. U.S. Environmental Protection Agency. April 13, 2020. EPA 430-R-20-002. Available at https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2018.