Quick answer
R-600a is isobutane, a hydrocarbon. It is not a fluorinated substance and it appears in none of the lists that trigger the familiar duties of Regulation (EU) 2024/573. The practical consequence splits in two.
- What does not apply. The hydrofluorocarbon quota in Article 16(1), because Article 3, point (4), defines HFCs as the substances listed in Section 1 of Annex I or mixtures containing them. The leak checks in Article 5(1), written for Annex I and Annex II Section 1 gases. The equipment record in Article 7(1), which follows exactly that scope. The recovery duty in Article 8(1) and the precautions in Article 4, both written for fluorinated greenhouse gases. The label in Article 12 and the sales restriction in Article 11(6), likewise.
- What does apply. Certification. Article 10(1) covers activities involving fluorinated greenhouse gases or relevant alternatives to them, including natural refrigerants, and Implementing Regulation (EU) 2024/2215 names hydrocarbons expressly in Article 2(1), points (b) and (c). Alongside that sits the whole of chemical safety law: CLP classification and labelling, the safety data sheet, dangerous goods, pressure equipment and explosive atmospheres.
Annex VI does list it: when the GWP of a mixture is calculated, isobutane (R-600a) is given the value 0. That is the only place in the regulation where it appears at all.
It contains no charge limits, no minimum room volumes, no separation distances, no explosive-atmosphere zone classes and no numeric transport thresholds. Those figures come from the refrigerating-system safety standards and from national law, not from the F-gas Regulation, and we do not reproduce standard text we cannot cite directly. The sections below say exactly where to look for each of them.
Where R-600a sits in the F-gas Regulation
It is worth going through this provision by provision, because "not a fluorinated gas" translates differently in each article.
| Provision | Scope as written | R-600a |
|---|---|---|
| Article 16(1) — quota | Hydrofluorocarbons, as defined in Article 3, point (4) | Outside |
| Article 5(1) — leak checks | 5 tonnes CO2 equivalent of Annex I gases, or 1 kg of Annex II Section 1 gases | Outside |
| Article 7(1) — equipment record | Equipment required to be checked under Article 5(1) | Outside |
| Article 8(1) — recovery | Operators of equipment containing fluorinated greenhouse gases | Outside |
| Article 11(6) — who may buy | Annex I and Annex II Section 1 gases | Outside |
| Article 12(1) — the F-gas label | Products and equipment containing fluorinated greenhouse gases | Outside |
| Annex VI — GWP of mixtures | Non-fluorinated substances used in the calculation | Listed, GWP 0 |
| Article 10(1) — certification | Fluorinated gases or relevant alternatives, including natural refrigerants | Inside |
The Annex VI value is not a curiosity. It matters whenever isobutane turns up as a component of a mixture: the GWP of a mixture is a weighted average, the sum of the weight fractions of the individual substances multiplied by their GWP, including substances that are not fluorinated greenhouse gases.
For a mixture of 60 % dimethyl ether, 10 % HFC-152a and 30 % isobutane: (60 % × 1) + (10 % × 124) + (30 % × 0), giving a total GWP of 13.0. The weight tolerance is plus or minus 1 %. Only emissible components that fulfil broadly the same function count in the calculation.
The footnote to Annex VI shows where the figure comes from: the isobutane value is taken from the 2018 WMO assessment, where it is given as very much less than 1, and is carried into the annex as 0. Substances not listed in the annex at all take the same default value of 0.
A mixture containing isobutane alongside an Annex I or Annex II substance is still a fluorinated mixture, with every consequence that follows. The natural status of one component does not lift the mixture out of the regime. If you work with blends, see the ban timetable and leak check frequency.
Where it is used, and why it ended up there
R-600a is the classic refrigerant of domestic refrigeration and of small self-contained equipment. The reason it ended up there is not commercial but calendar-driven: Annex IV closed exactly those categories to fluorinated gases, one row at a time.
| Annex IV point | Equipment | Limit | Date |
|---|---|---|---|
| 2(a) | Domestic refrigerators and freezers | HFCs with GWP of 150 or more | 1.1.2015 |
| 2(b) | The same appliances | Any fluorinated greenhouse gas, except if required to meet safety requirements at the site of operation | 1.1.2026 |
| 3(b) | Commercial self-contained refrigerators and freezers | HFCs with GWP of 150 or more | 1.1.2022 |
| 3(c) | The same equipment | Other fluorinated greenhouse gases with GWP of 150 or more | 1.1.2025 |
| 4 | Any self-contained refrigeration equipment except chillers | GWP of 150 or more, except where safety requirements at the site of operation require otherwise | 1.1.2025 |
Read together, those rows leave very little room for a fluorinated gas in a small, hermetic, series-manufactured appliance. Hydrocarbons and CO2 are the alternatives that remain, and for small charges isobutane is the usual choice.
Watch the recurring wording "except if required to meet safety requirements at the site of operation". It is not a general escape hatch. Article 13(19) requires the operator to be able to prove that the relevant safety requirements at that particular location do not permit equipment using gases below the specified GWP, and Article 13(20) requires the documentation to be kept for at least 5 years. Article 12(15) adds a labelling duty: the product must state that it is to be used only where required by the safety requirements or national safety standards, and those requirements or standards must be specified on the label.
Do not read the absence of a prohibition as a recommendation. The regulation nowhere says you must use R-600a; it says only that, after the dates above, you can no longer place the equivalent fluorinated-gas appliance on the market.
Certification: hydrocarbons are inside the scheme
This is the part that firms moving to natural refrigerants miss most often. The gas leaving the F-gas regime does not take the job out of the certification regime.
Article 10(1) of Regulation (EU) 2024/573 requires natural persons to be certified for activities involving fluorinated greenhouse gases or relevant alternatives to fluorinated greenhouse gases, including natural refrigerants, where relevant. Implementing Regulation (EU) 2024/2215 turns that into operational text:
- Article 2(1), point (b) — installation of the equipment listed in Article 1 containing fluorinated greenhouse gases or the alternative substances ammonia (NH3), carbon dioxide (CO2) or hydrocarbons.
- Article 2(1), point (c) — repair, maintenance or servicing, as well as decommissioning of the same equipment, with the same list of alternatives.
- Article 2(2) — legal persons carrying out installation, repair, maintenance, servicing or decommissioning for third parties on that equipment, again with the alternative substances included.
Points (a) and (d) of Article 2(1) — leak checks and recovery — are written for fluorinated greenhouse gases only. The difference is deliberate and worth remembering.
Which certificate covers hydrocarbons? Article 3(2) sets out six types. Hydrocarbons have no certificate of their own: they sit inside the same certificates as the fluorinated gases.
| Certificate | Substances | Charge limit |
|---|---|---|
| A1 | Fluorinated greenhouse gases and hydrocarbons | None |
| A2 | Fluorinated greenhouse gases and hydrocarbons | Under 3 kg, or under 6 kg for labelled hermetically sealed systems |
| B | Carbon dioxide (CO2) | No stated limit |
| C | Ammonia (NH3) | No stated limit |
Annex I to the implementing regulation shows how that is examined. Certificates A1 and A2 add heading 12 — installation and good practice of servicing for equipment and systems relying on hydrocarbons — on top of the common core. For Certificates B and C, at least one of the theoretical questions must relate to the specifics of hydrocarbons.
Article 6(1) of Implementing Regulation (EU) 2024/2215 requires two things of the legal person: employment of a sufficient number of certified natural persons to cover the expected volume of activities, and proof that the necessary tools and procedures are available to them. With an extremely flammable refrigerant, the second condition is not a formality. Article 10(12) of the base regulation additionally requires you to verify a subcontractor's certificates before assigning the activity.
For the overall picture of the categories, see the certificate categories and what changes on site with low-GWP refrigerants.
Safety class A3: what it means and where it comes from
The first point is a legal one: the F-gas Regulation does not assign safety classes. The expressions A1, A2L, A3 and B2L appear nowhere in the text of Regulation (EU) 2024/573. They come from the refrigerant classification standards, ISO 817 and ANSI/ASHRAE 34, and their technical consequences are worked out in the system safety standards.
Manufacturers' technical documentation describes the scheme like this: the letter indicates toxicity — A for lower toxicity, B for higher toxicity — and the figure indicates flammability, from class 1, practically non-flammable under most conditions of use, through class 2L, mildly flammable, class 2, flammable, to class 3, extremely flammable. Hydrocarbons generally populate class 3. That is where the usual designation of isobutane comes from: A3.
The second point is chemical, and you can verify it directly in the safety data sheet of the product in front of you. The classification under Regulation (EC) 1272/2008, from the supplier sheet:
| Item | Value from the safety data sheet |
|---|---|
| CLP classification | Flam. Gas 1A, H220 — extremely flammable gas; Press. Gas (Liq.), H280 — contains gas under pressure, may explode if heated |
| Pictograms and signal word | GHS02 and GHS04; Danger |
| Explosive limits | Lower 1.5 vol %; upper 9.4 vol % |
| Auto-ignition temperature | 460 °C |
| Boiling point | −12 °C |
| Gas density | Heavier than air |
| Acute toxicity | Not classified; LC50 inhalation, rat, 4 h: above 800 000 ppmv |
| Other hazards | Asphyxiant in high concentrations, and those concentrations are within the flammability range; contact with the liquid may cause cold burns or frostbite |
The combination of a gas heavier than air and a low lower explosive limit is why floor-level ventilation and the elimination of ignition sources are the fixed points of any R-600a procedure. Leaked gas sinks and pools.
Maximum permitted charge, minimum room volume, ventilation and detection requirements and zoning for explosive atmospheres are set in the refrigerating-system safety standards — the EN 378 family and ISO 5149 for the general framework, the IEC and EN 60335-2 series for appliances — and in national law. We do not reproduce them: we could not consult the text of those standards, and a wrong figure here would be worse than no figure. For equipment intended for potentially explosive atmospheres, the Union framework act is Directive 2014/34/EU.
Working on a class 3 refrigerant
Run the risk analysis before you start
Annex I to Implementing Regulation (EU) 2024/2215, heading 12, requires a risk analysis before starting the work and elimination of the sources of danger or, where elimination is not possible, their identification. It is an examined competence, not a suggestion.
Prepare the work area and pick the right tools
The same heading requires preparation of the area and selection of appropriate tools, equipment and protective equipment for working on flammable refrigerants: gas detection, leak detection, ventilation, personal protective equipment, vacuum pumps and recovery units.
Check the site safety measures
Signs, emergency exits, gas sensors and gas alarms. Heading 12 lists them expressly as items to be checked at the location of the system, in line with applicable rules.
Recover safely and fill with nitrogen
Recovering the flammable refrigerant from the system and filling the system with nitrogen are separate steps in the list of practical competences, before the circuit is opened.
Open the system, change the component, close it again
The order is the one in heading 12: opening, removal and exchange of a component, closing, then a pressure test for tightness and a vacuum test to remove moisture.
Charge the correct volume
The charge of flammable refrigerant is calculated according to the applicable safety standards, which Annex I points to rather than replaces. The actual figure comes from the equipment documentation and the applicable standard.
Leak-check by a direct method and write the report
Both are express requirements of heading 12. The report on the service work performed closes the procedure.
The list above is not a complete safety procedure and does not replace the equipment manufacturer's instructions. It is the competence content that the implementing regulation requires to be examined for Certificates A1 and A2 — a good indicator of what an inspector expects you to know.
Cylinders and transport
Isobutane travels under pressure and as a rule falls inside the dangerous goods regime. The identification data come from section 14 of the safety data sheet for the specific product, in the format required by Regulation (EU) 2020/878. For the product verified while this page was written:
- UN 1969, proper shipping name ISOBUTANE.
- Transport hazard class 2.1, flammable gases.
- Packing group: not applicable.
The applicable Union framework is Directive 2008/68/EC on the inland transport of dangerous goods. The numeric thresholds, transport document obligations, limited-quantity exemptions, equipment required on board and staff training requirements are set there, not here, and must be read in the text in force.
The UN number and class differ from refrigerant to refrigerant, and a mixture has its own classification. Check the sheet for the product you actually have, not a similar one. Responsibility in transit is covered in the cylinder transport guide, and storage conditions in the storage guide.
The purchase restriction in Article 11(6) of the F-gas Regulation refers to Annex I and Annex II Section 1 gases, so not to R-600a. That does not mean anyone may work on it: the certification requirement for installation, repair, maintenance, servicing and decommissioning stands, and it attaches to the activity, not to the purchase. For reading the sheet properly, see how to read a safety data sheet.
Checklist
- You have confirmed the refrigerant really is pure R-600a, not a blendA mixture that also contains an Annex I or Annex II substance stays inside the F-gas regime, with quota, leak checks and label.
- The certificate covers the activity, not just the gasArticle 2(1), points (b) and (c), of Implementing Regulation (EU) 2024/2215: installation, repair, maintenance, servicing, decommissioning. Hydrocarbons sit inside Certificates A1 and A2.
- The company holds a legal-person certificate for third-party workArticle 2(2) and Article 6(1): enough certified staff plus proof of tools and procedures.
- The product safety data sheet is to handSections 2 and 9 for hazards and properties, 4 and 6 for incidents, 14 for transport.
- Ignition sources are removed from the work areaThe lower explosive limit is 1.5 vol %, and the gas is heavier than air, so it accumulates low down.
- Gas detection and ventilation are workingHeading 12 of Annex I to the implementing regulation lists them among the service equipment needed for flammable refrigerants.
- The charge is the one in the equipment documentationLimits come from the applicable safety standards and the manufacturer's instructions, not from the F-gas Regulation.
- The transport classification has been checked for this productSection 14 of the sheet and the Directive 2008/68/EC regime.
- If you are replacing a fluorinated gas, the old file is closed properlyRecovery under Article 8, the record entry under Article 7 and relabelling under Article 12(3) are still owed for the old charge.
Frequently asked questions
Does R-600a count against HFC quota?
No. Article 3, point (4), defines hydrofluorocarbons as the substances listed in Section 1 of Annex I or mixtures containing any of those substances. Isobutane is not among them, so Article 16(1) does not apply to it. Note the trap, though: a mixture containing isobutane and an HFC is, by definition, an HFC.
Do I have to leak-check an R-600a system?
Not under Article 5(1) of Regulation (EU) 2024/573, which applies to equipment containing more than 5 tonnes of CO2 equivalent of Annex I gases or 1 kg or more of Annex II Section 1 gases. Requirements from other legislation — workplace safety, system standards, national rules — are settled separately; confirm them with your competent authority.
Do I need a certificate to work on an isobutane refrigerator?
For installation, repair, maintenance, servicing or decommissioning, yes. Article 2(1), points (b) and (c), of Implementing Regulation (EU) 2024/2215 names hydrocarbons expressly, and the cover comes through Certificate A1 or A2, depending on the charge limit.
Is there a separate certificate for hydrocarbons?
No. Unlike CO2, which has Certificate B, and ammonia, which has Certificate C, hydrocarbons have no certificate of their own: they are inside A1 and A2 alongside the fluorinated gases. Heading 12 of Annex I adds the specific examination content.
Why does Annex VI give isobutane a GWP of 0?
Because the value the annex takes, from the 2018 WMO assessment, is given as very much less than 1 and is listed as 0. The same default value of 0 applies to substances that do not appear in the annex at all. The practical consequence: the isobutane fraction of a blend does not raise the blend's calculated GWP.
Does an R-600a cylinder need the F-gas label?
No. Article 12(1), point (g), covers containers of fluorinated greenhouse gases, and R-600a is not one. The container remains subject to hazard labelling under Regulation (EC) 1272/2008 — for the product verified here, GHS02 and GHS04, the signal word Danger and hazard statement H220.
Official sources
Articles 3, 4, 5, 7, 8, 10, 11, 12, 13 and 16, together with Annexes IV and VI, were read directly in the Official Journal text. The certification implementing regulation was read in full, including Annex I. The hazard and transport data come from the supplier's safety data sheet for the specific product.
Currency of this page and limits of responsibility
R-600a is an extremely flammable gas. This page explains its legal position relative to the F-gas Regulation. It is not a safety procedure, it carries no charge limits, and it does not replace the equipment manufacturer's instructions, the refrigerating-system safety standards or national rules. The work is carried out by certified personnel with appropriate tools and procedures.
General information prepared by EgoLog from Regulation (EU) 2024/573, Implementing Regulation (EU) 2024/2215, official Commission material and the supplier's safety data sheet. It is not legal, safety or engineering advice.
Hazard data, physical properties and transport information must always be checked in the sheet for the product you actually use, in its current version. Pressure equipment, explosive atmosphere and occupational safety requirements fall under other acts; confirm them with your supplier and your national competent authority.