Phaseout of Class II Ozone-Depleting Substances | US EPA (2024)

Additional Information

Information for Equipment Owners and Operators

“Class II” ozone-depleting substances (ODSA 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 (http://www.epa.gov/ozone/science/ods/index.html) of class I and class II substances with their ODPs, GWPs, and CAS numbers are available.) have an ozone depletion potentialA number that refers to the amount of ozone depletion caused by a substance. The ODP is the ratio of the impact on ozone of a chemical compared to the impact of a similar mass of CFC-11. Thus, the ODP of CFC-11 is defined to be 1.0. Other CFCs and HCFCs have ODPs that range from 0.01 to 1.0. The halons have ODPs ranging up to 10. Carbon tetrachloride has an ODP of 1.2, and methyl chloroform's ODP is 0.11. HFCs have zero ODP because they do not contain chlorine. A table of all ozone-depleting substances (http://www.epa.gov/ozone/science/ods/index.html) shows their ODPs, GWPs, and CAS numbers. less than 0.2, and are all hydrochlorofluorocarbonsA 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 table of ozone-depleting substances (http://www.epa.gov/ozone/science/ods/classtwo.html) shows their ODPs, GWPs, and CAS numbers. HCFCs are numbered according to a standard scheme (http://www.epa.gov/ozone/geninfo/numbers.html). (HCFCs). HCFCs were developed as transitional substitutes for Class I ODS and are subject to a later phaseout schedule than Class I ODS.

HCFCs were used in a wide variety of applications, including refrigeration, air conditioning, foam blowing, solvents, aerosols, and fire suppression. Although 34 HCFCs are subject to the phaseout, only a few were commonly used. Historically, the most widely used included HCFC-22 (usually as a refrigerant), HCFC-141b (as a solvent and foam-blowing agent), and HCFC-142b (as a foam-blowing agent and component in refrigerant blends). While most HCFCs have been phased out, there are some uses that continue, such as for servicing refrigeration and air-conditioning equipment and in fire suppression. Learn more about common HCFCs and their uses.

Some HCFCs, like HCFC-22, are also a component in refrigerant blends. While these blends are not listed among the 34 controlled HCFCs, they are subject to the same rules because they contain Class II ODS. Common refrigerant blends that contain HCFC-22 included R-401A, R-402A, R-408A, R-409A, R-414B, and R-502A.

The Phaseout of HCFCs

Key Resources

As a Party to the Montreal ProtocolThe international treaty governing the protection of stratospheric ozone. The Montreal Protocol on Substances That Deplete the Ozone Layer and its amendments control the phaseout of ODS production and use. Under the Montreal Protocol, several international organizations report on the science of ozone depletion, implement projects to help move away from ODS, and provide a forum for policy discussions. In addition, the Multilateral Fund provides resources to developing nations to promote the transition to ozone-safe technologies. The full text of the Montreal Protocol (http://ozone.unep.org/Publications/MP_Handbook/Section_1.1_The_Montreal_Protocol/) is available from the United Nations Environmental Programme (UNEP)., the United States must incrementally decrease HCFC consumption and production, culminating in a complete HCFC phaseout in 2030. HCFC usage must be reduced to at least 90 percent below baseline levels in 2015 and to at least 99.5 percent below baseline levels in 2020.

Section 605 of the Clean Air ActA law amended by Congress in 1990. Title VI of the CAA (http://www.epa.gov/ozone/title6/index.html) directs EPA to protect the ozone layer through several regulatory and voluntary programs. Sections within Title VI cover production of ozone-depleting substances (ODS), the recycling and handling of ODS, the evaluation of substitutes, and efforts to educate the public. establishes the U.S. phaseout targets for Class II substances. In 1993, EPA established the phaseout framework and the "worst-first" approach, which focused first on HCFC-22, HCFC-141b, and HCFC-142b because they have the highest ozone depletion potentials of all HCFCs.

The U.S. schedule for meeting the Montreal Protocol phaseout requirements is summarized in the following table.

U.S. Action to Meet the Montreal Protocol Phaseout Schedule
Year to Be ImplementedImplementation of HCFC Phaseout through Clean Air Act RegulationsYear to Be ImplementedPercent Reduction in HCFC Consumption and Production from Baseline
2003No production or import of HCFC-141b200435.0%
2010No production or import of HCFC-142b and HCFC-22, except for use in equipment manufactured before January 1, 2010201075.0%
2015No production or import of any other HCFCs, except as refrigerants in equipment manufactured before January 1, 2020201590.0%
2020No production or import of HCFC-142b and HCFC-22202099.5%
2030No production or import of any HCFCs2030100.0%

More about the HCFC Allowance System

Common HCFCs and Their Uses

Historic uses for HCFCs include:

  • HCFC-22: used as a refrigerant in several applications such as unitary air conditioners, cold storage, retail food refrigeration equipment, chillers, and industrial process refrigeration. Also historically used (in smaller quantities) as a blowing agent for certain foam applications and as a propellant in aerosols.
  • HCFC-141b: used as a blowing agent in rigid polyurethane foams and integral skim foams and in aerosol solvent cleaning applications.
  • HCFC-142b: used as a blowing agent in extruded polystyrene boardstock. Also used in small quantities in refrigerant blends and as a retrofit refrigerant, such as in motor vehicle air conditioners that previously used chlorofluorocarbonA compound consisting of chlorine, fluorine, and carbon. CFCs are very stable in the troposphere. They move to the stratosphere and are broken down by strong ultraviolet (UV) light, where they release chlorine atoms that then deplete the ozone layer. CFCs are commonly used as refrigerants, solvents, and foam blowing agents. The most common CFCs are CFC-11, CFC-12, CFC-113, CFC-114, and CFC-115. The ozone depletion potential (ODP) for each CFC is, respectively, 1, 1, 0.8, 1, and 0.6. A table of all ozone-depleting substances (http://www.epa.gov/ozone/science/ods/index.html) shows their ODPs, global warming potentials (GWPs), and CAS numbers. CFCs are numbered according to a standard scheme (http://www.epa.gov/ozone/geninfo/numbers.html). (CFC)-12.
  • HCFC-123: used in centrifugal chillers and portable fire extinguishers.
  • HCFC-124: used in some sterilant mixtures and as a component in some CFC-12 retrofit refrigerants. Can be used as aretrofit to replaceCFC-114 in some heat pumps and special air conditioning equipment.
  • HCFC-225ca and HCFC-225cb: used as a solvent and aerosol solvent. Also historicallyused in small quantities in adhesives, coatings, and inks.
  • HCFC-21: used as a refrigerant in highly specialized cooling loops.

The phaseout restricts the use of these HCFCs, and EPA continues to evaluate HCFC alternatives through its Significant New Alternatives Policy (SNAP) program.

Phaseout of Class II Ozone-Depleting Substances | US EPA (2024)

FAQs

What is the EPA phase out of ODS? ›

The Phaseout of Ozone-Depleting Substances

Class I substances, such as chlorofluorocarbons (CFCs) and halons, have a higher ozone depletion potential and have been phased out in the U.S.; with a few exceptions, this means no one can produce or import class I substances.

What is the ozone-depleting substances phase out plan? ›

The Montreal Protocol on Substances that Deplete the Ozone Layer is a global agreement to protect the Earth's ozone layer by phasing out the chemicals that deplete it. This phase-out plan includes both the production and consumption of ozone-depleting substances.

What is the protocol for phasing out ozone-depleting substances? ›

The Montreal Protocol, finalized in 1987, is a global agreement to protect the stratospheric ozone layer by phasing out the production and consumption of ozone-depleting substances (ODS).

What is the difference between Class 1 and Class 2 ODS? ›

Ozone-depleting substances are divided into two classes: Class I includes the fully halogenated CFCs, halons, and the ODSs that are the most threatening to the ozone layer. Class II compounds are those substances that are known or reasonably anticipated to have harmful effects on the stratospheric ozone layer.

What are the EPA phases? ›

“the process that evaluates the likelihood that adverse ecological effects may occur or are occurring as a result of exposure to one or more stressors.” An ERA includes three primary phases: problem formulation, analysis, and risk characterization.

Have HCFCs been phased out? ›

Developed countries completely phased them out by 2020. Developing countries agreed to start their phase-out process in 2013 and with a complete phase-out of HCFCs targeted by 2030.

Which refrigerant is being phased out by 2030? ›

R-22 is an HCFC refrigerant that is often used in air-conditioning equipment. To protect the Earth's protective ozone layer, the United States is phasing out R-22, along with other chemicals.

What are the ODS regulations? ›

The ODS Regulation bans all ODS, with derogations for essential uses and where no technically feasible alternatives are available.

When were all CFCs phased out? ›

In 1996, when CFC-based aerosols were phased out in developed countries, CFC-free replacement inhalers were not available for the hundreds of millions of patients with asthma/chronic obstructive pulmonary disease worldwide who relied on them, and so a temporary exemption was allowed.

What refrigerants will be phased out? ›

U.S. Refrigerant Phase Out Chart & Info
Phase-Out ActionYear
R134a, R404a and R507a can't be used on low temp retail refrigeration units2020
R22 and R142b can't be produced or imported with any exceptions2020
R134a can't be used in the AC on light-duty motor vehiclesModel year 2021
7 more rows

What are the 5 ozone-depleting substances? ›

ODS include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl bromide, carbon tetrachloride, hydrobromofluorocarbons, chlorobromomethane, and methyl chloroform.

What is the phaseout date for the production and import of new R-22 in the US? ›

As of January 1, 2020, production and import of R22 refrigerant will be illegal in the United States. Of course, continued use of your air conditioner (AC) or heat pump system using R22 refrigerant is allowed.

Which refrigerant has the highest ozone depletion potential? ›

The correct answer is CFCs. CFCs are chlorofluorocarbons generally used in refrigerant industries. CFCs has the maximum potential amongst chlorocarbons because of the presence of three chlorine atoms in the molecule. Chlorine is responsible for ozone layer depletion.

What are the ozone-depleting substance regulations? ›

Environment Canada, through the Ozone-depleting Substances Regulations, 1998 (SOR/99-7) and subsequent amendments under the Canadian Environmental Protection Act (1999), controls the import, manufacture, use, sale and export of bulk chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrobromofluorocarbons ( ...

Which refrigerant is being phased out? ›

Unfortunately, releases of HCFCs deplete the Earth's protective ozone layer and contribute to climate change. R-22 is an HCFC refrigerant that is often used in air-conditioning equipment. To protect the Earth's protective ozone layer, the United States is phasing out R-22, along with other chemicals.

When were R-22 and R 142b phased out in the United States? ›

On January 1, 2010, the phase-out and ban of HCFC-22 (i.e., R-22) and R142b refrigerants began with a requirement for the consumption of R-22 and R-142b refrigerants to be reduced by 75% below the U.S. baseline.

What are the new EPA refrigerant regulations 2025? ›

New EPA Refrigerant Regulations 2025

In 2025, the goal is to eliminate all refrigerants with a high Global Warming Potential. In practice, this means that all new AC units must use refrigerants with a GWP rating of 750 or less.

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