Resources for Stationary Refrigeration and Air-Conditioning Equipment Technicians

Learn about the phaseout of ODSODSA compound that contributes to stratospheric ozone depletion. ODS include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl bromide, carbon tetrachloride, hydrobromofluorocarbons, chlorobromomethane, and methyl chloroform. ODS are generally very stable in the troposphere and only degrade under intense ultraviolet light in the stratosphere. When they break down, they release chlorine or bromine atoms, which then deplete ozone. A detailed list of class I and class II substances with their ODPs, GWPs, and CAS numbers is available., and how the phaseout affects technicians and contractors.

Refrigerants with “22a” or “R-22a” in their names are highly flammable substances that are not approved for use in existing air-conditioning systems. These refrigerants have never been submitted to EPA for review of their health and environmental impacts. Using these propane-based refrigerants in an air conditioner that is not designed for flammable refrigerants poses a threat to homeowners and service technicians. EPA is investigating instances where propane-based refrigerants have been marketed and used as a substitutes for  hydrochlorofluorocarbon hydrochlorofluorocarbon A compound consisting of hydrogen, chlorine, fluorine, and carbon. The HCFCs are one class of chemicals being used to replace the CFCs. They contain chlorine and thus deplete stratospheric ozone, but to a much lesser extent than CFCs. HCFCs have ozone depletion potentials (ODPs) ranging from 0.01 to 0.1. Production of HCFCs with the highest ODPs are being phased out first, followed by other HCFCs. A detailed list of ozone-depleting substances with their ODPs, GWPs, and CAS numbers is available.  (HCFC)-22 (also called R-22) and has taken enforcement actions where appropriate.

Learn about EPA’s efforts to enforce regulations to protect the  ozone layer ozone layer The region of the stratosphere containing the bulk of atmospheric ozone. The ozone layer lies approximately 15-40 kilometers (10-25 miles) above the Earth's surface, in the stratosphere. Depletion of this layer by ozone depleting substances (ODS) will lead to higher UVB levels, which in turn will cause increased skin cancers and cataracts and potential damage to some marine organisms, plants, and plastics. See Basic Ozone Layer Science for more details. .