Hydrofluorocarbons and the rules for US and UK refrigerants
Hydrofluorocarbons face supply phase-downs and equipment restrictions, not a blanket ban. Check the 18 Kigali HFCs and the separate US, GB and NI rules.
Hydrofluorocarbons, or HFCs, contain hydrogen, fluorine and carbon and are used in refrigeration and air conditioning. They face supply phase-downs and equipment-specific restrictions, rather than a blanket ban on every HFC or existing system. EPA explains their uses and regulation.
The Kigali Amendment controls 18 individual HFCs under the Montreal Protocol. Domestic rules then set separate requirements for refrigerant supply, equipment and servicing. For a US or UK purchase, the gas name alone can't show whether equipment meets the rules. The territory and activity also matter. Kigali's treaty text, US equipment rules and GB equipment prohibitions address different questions.
What are HFCs?
HFC stands for hydrofluorocarbon. People also call them HFC gas. These gases contain no chlorine, unlike chlorine-containing CFCs and HCFCs associated with ozone depletion. HFC controls address their greenhouse effect. Replacing an ozone-depleting refrigerant with an HFC does not remove the climate concern. See EPA's HFC background.
The rules use global warming potential, or GWP. The table below uses the 100-year values in Annex F for treaty accounting. Use the GWP required by the applicable rule, not a newer scientific value. Jurisdictions can also use different substance lists. Annex F identifies the controlled HFCs and their GWPs.
The 18 Annex F hydrofluorocarbons
Annex F contains 17 substances in Group I and HFC-23 in Group II. This is a controlled-substance list, not a list of 18 commercial refrigerant products. It does not mean every entry is commonly used as a refrigerant. HFC-161 is not an Annex F substance. Source for every entry and value below: Kigali Amendment.
| Annex F substance | Treaty GWP |
|---|---|
| HFC-134 | 1,100 |
| HFC-134a | 1,430 |
| HFC-143 | 353 |
| HFC-245fa | 1,030 |
| HFC-365mfc | 794 |
| HFC-227ea | 3,220 |
| HFC-236cb | 1,340 |
| HFC-236ea | 1,370 |
| HFC-236fa | 9,810 |
| HFC-245ca | 693 |
| HFC-43-10mee | 1,640 |
| HFC-32 | 675 |
| HFC-125 | 3,500 |
| HFC-143a | 4,470 |
| HFC-41 | 92 |
| HFC-152 | 53 |
| HFC-152a | 124 |
| HFC-23 | 14,800 |
An HFC refrigerant list for procurement must distinguish pure substances from blends. R-410A contains HFC-32 and HFC-125. R-404A contains HFC-125, HFC-143a and HFC-134a. Neither blend adds an entry to Annex F, and a component's GWP is not the blend's GWP. Check the mixture identification in GOV.UK's F-gas guidance.
How the Kigali phase-down works
Kigali limits production and consumption against separate baselines. The percentages below are quantities remaining, not reductions. For example, 60% remaining means a 40% reduction against the applicable baseline. Exemptions qualify these headline schedules. UNEP publishes the schedules and party groups.
| Party group | Baseline components | Permitted level remaining |
|---|---|---|
| Standard non-Article 5 | 2011–2013 HFC average plus 15% of the corresponding HCFC baseline | 90% in 2019–2023; 60% in 2024–2028; 30% in 2029–2033; 20% in 2034–2035; 15% from 2036 |
| Special non-Article 5 | 2011–2013 HFC average plus 25% of the corresponding HCFC baseline | 95% in 2020–2024; 65% in 2025–2028; then the same 30%, 20% and 15% periods |
| Article 5 Group 1 | 2020–2022 HFC average plus 65% of the corresponding HCFC baseline | 100% in 2024–2028; 90% in 2029–2034; 70% in 2035–2039; 50% in 2040–2044; 20% from 2045 |
| Article 5 Group 2 | 2024–2026 HFC average plus 65% of the corresponding HCFC baseline | 100% in 2028–2031; 90% in 2032–2036; 80% in 2037–2041; 70% in 2042–2046; 15% from 2047 |
The special non-Article 5 group comprises Belarus, Russia, Kazakhstan, Tajikistan and Uzbekistan. Article 5 Group 2 comprises Bahrain, India, Iran, Iraq, Kuwait, Oman, Pakistan, Qatar, Saudi Arabia and UAE. Other Article 5 parties follow Group 1. The HCFC component belongs in each baseline calculation even though the schedule controls HFCs. See UNEP's group definitions.
A phase-down is not a removal order.
The percentages limit production and consumption. They do not clear a system for installation or sale, so check the domestic rule for the activity in front of you.
US HFC rules under the AIM Act
The allowance programme and the Technology Transitions rules do different jobs. Technology Transitions comes from the American Innovation and Manufacturing Act (AIM Act). Under the published allowance schedule, production and consumption ceilings are 60% of baseline in 2024–2028. They fall to 30% in 2029–2033, 20% in 2034–2035 and 15% from 2036. These are aggregate ceilings, not individual company allocations or equipment bans. See 40 CFR 84.7.
Technology Transitions addresses products and systems. Section 84.54 distinguishes manufacture and import from later product sale, distribution and export restrictions. It also sets system installation restrictions. A product sell-through period must not be treated as permission to install a field-assembled system. The activity named in the rule matters as much as the refrigerant. See 40 CFR 84.54.
EPA published its reconsideration final rule on 26 May 2026, effective 27 July 2026. Use that final text rather than the October 2025 proposal for procurement checks. Consult the final rule and EPA's regulatory actions page.
Cold-storage warehouse systems and supermarket systems show why one installation date does not fit every sector. Under the published installation rule, both restrictions cover a regulated substance or a blend that contains one. Cold storage is restricted at a GWP of 700 or greater from 27 July 2026. Supermarket systems are restricted at a GWP of 1,400 or greater from 1 January 2027. From 1 January 2032 the same paragraphs tighten those installs: GWP 150 or greater where the charge is 200 pounds or more and the system is not a cascade high-temperature side, and GWP 300 or greater for a smaller charge or a cascade high-temperature side. A building permit approved before 5 October 2023 can extend the applicable installation date by one year, but only if it specifies the restricted refrigerant, or a blend containing it, and the system. See section 84.54.
Residential and light-commercial air-conditioning or heat-pump systems that are not variable refrigerant flow (VRF) are on a different path. Installation of a system using a regulated substance, or a blend containing one, at a GWP of 700 or greater is restricted from 1 January 2025, unless every specified component was manufactured or imported before that date. That inventory path does not clear every old component. See section 84.54.
Those dates describe the published rule. They do not establish whether a deadline is enforceable for a particular project. Before procurement or installation, check current EPA sector requirements, applicable court orders and any relief. A federal rule check also does not determine compliance with state requirements.
Great Britain and Northern Ireland have different rules
Great Britain uses its amended Regulation 517/2014 regime. Northern Ireland applies EU Regulation 2024/573 from 11 March 2024, as DAERA confirms. A UK-wide equipment checklist that treats both territories alike can therefore give the wrong result.
Great Britain
The GB quota schedule specifies 31% for 2024–2026, 24% for 2027–2029 and 21% for 2030. Those percentages use the GB-adjusted statutory calculation, including the 2015–2019 GB-market average and specified adjustments. Do not label them simply as percentages of 2009–2012 consumption. See Annex V.
For equipment, Annex III point 15 prohibits placing on the market, from 1 January 2025, single-split air-conditioning systems containing less than 3 kg of F-gases that contain, or whose functioning relies on, F-gases with a GWP of 750 or more. This category restriction does not order removal of every installed system. The threshold includes 750. See Annex III, point 15.
Servicing needs a separate check. GB Article 13 restricts the use of gases with GWP at least 2,500 to service refrigeration equipment with a charge of at least 40 tonnes CO₂ equivalent. Exceptions apply, including conditional relief for reclaimed or recycled gas until 2030. Check Article 13, rather than applying Northern Ireland's newer provisions.
Northern Ireland
EU Regulation 2024/573 has expanded refrigeration servicing restrictions from 1 January 2025 and air-conditioning/heat-pump restrictions from 1 January 2026. Conditional reclaimed and recycled gas relief has different periods. Read the relevant category in Article 13 before assessing a service job.
Equipment restrictions also require an exception check. For chillers above 12 kW, corrected Annex IV point 7(d) uses GWP 750 or more, with a 1 January 2027 date. Read the 24 March 2025 corrigendum alongside the regulation.
Specific semiconductor chillers have a derogation for 2027–2029 under Regulation 2026/286. Specified compressed-air refrigerated dryers have one for 2027–2030 under Regulation 2026/1975. These are limited exceptions, not general extensions. Article 13(3) also excludes refrigeration equipment with an authorised Article 11(5) exemption from that servicing restriction. An equipment derogation can therefore affect servicing.
What to check before buying or servicing equipment
Start with the pure gas or blend identity and the GWP required by the relevant law. Then record the territory, equipment category and activity: manufacture, import, placing on the market, installation or servicing. Check the date and any exception against that exact combination. The US rule, GB annex and EU regulation do not regulate those activities interchangeably.
RegAffairs AI has an answer on HFC regulation. That page is not a guarantee of complete US or UK coverage. For a specific purchase, the equipment category and any exception still matter more than the label "HFC refrigerant" alone.