Quick answer
R-744 is carbon dioxide used as a refrigerant. It is not a fluorinated substance, so Regulation (EU) 2024/573 touches it only indirectly: through the prohibitions that pushed fluorinated gases out of commercial refrigeration and made room for the alternatives.
- What does not apply. The quota in Article 16(1), the leak checks in Article 5(1), the record in Article 7(1), the recovery duty in Article 8(1), the label in Article 12 and the purchase restriction in Article 11(6). Every one of them is written for fluorinated greenhouse gases listed in Annex I or in Section 1 of Annex II.
- What does apply. Certification. Article 10(1) covers relevant alternatives to fluorinated greenhouse gases, including natural refrigerants, and Implementing Regulation (EU) 2024/2215 creates a dedicated one: Certificate B, for carbon dioxide.
- What the F-gas Regulation does not address at all. Pressure. A transcritical CO2 system works well above the pressures usual in HFC refrigeration, and when it stops the standstill pressure climbs. The applicable regime comes from pressure equipment law and from the system safety standards.
One drafting detail is worth noticing: in the Annex VI table, which lists non-fluorinated substances with their GWP for mixture calculations, carbon dioxide does not appear. The annex says expressly that for other substances not listed in it a default value of 0 applies. CO2 is the very reference against which every other gas's GWP is measured.
It contains no design pressures, no standstill-pressure values, no charge limits, no minimum room volumes, no alarm thresholds for CO2 sensors and no numeric transport thresholds. Those come from pressure equipment law, from the refrigerating-system safety standards, from the manufacturer's documentation and from national rules. This page says where each one lives; it does not reproduce them.
Outside the F-gas regime: what falls away and what does not
The wording of each article decides. The table below shows the scope as written, and where R-744 lands.
| Provision | Scope as written | R-744 |
|---|---|---|
| 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 6 — leakage detection system | Equipment with 500 tonnes CO2 equivalent or more of Annex I 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 12 — labelling | Products, equipment and containers with fluorinated greenhouse gases | Outside |
| Annex VI — GWP of mixtures | Non-fluorinated substances listed for the calculation | Not listed, default value 0 |
| Article 10(1) — certification | Fluorinated gases or relevant alternatives, including natural refrigerants | Inside |
Beware of one frequent confusion. Article 6 not applying does not mean a CO2 system is left without gas detection. Quite the opposite: Annex I to Implementing Regulation (EU) 2024/2215, heading 13, requires the certified person to know the safety requirements for service tools and equipment such as gas detection, leak detection and personal protective equipment, and to check that signs, emergency exits, gas sensors and gas alarms are in place at the location of the system, in line with applicable rules. The duty no longer comes from the F-gas Regulation, but the technical content survives.
The same goes for paperwork: the Article 7 record no longer applies, yet heading 13 expressly requires writing a report about the performed service work. The documentation habit does not disappear, it only changes its legal basis.
Why commercial refrigeration moved to CO2
Annex IV closed, row by row, exactly the categories a supermarket or a logistics platform lives in.
| Annex IV point | Equipment | Limit | Date |
|---|---|---|---|
| 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 | 1.1.2025 |
| 5(b) | Other refrigeration equipment, chillers and points 4 and 6 excluded | Any fluorinated greenhouse gas with GWP of 2 500 or more | 1.1.2025 |
| 5(c) | The same equipment | GWP of 150 or more | 1.1.2030 |
| 6 | Multipack centralised refrigeration systems for commercial use, rated capacity of 40 kW or more | Annex I gases with GWP of 150 or more | 1.1.2022 |
The point 6 prohibition does not apply in the primary refrigerant circuit of cascade systems, where fluorinated greenhouse gases with a GWP of less than 1 500 may be used. That sentence is the legal basis of the classic cascade architecture: CO2 on the low-temperature stage, a fluorinated refrigerant below 1 500 on the primary circuit.
On top of that regulatory pressure sit the servicing prohibitions. Article 13(3): from 1 January 2025, using a fluorinated greenhouse gas with a GWP of 2 500 or more to maintain or service any refrigeration equipment is prohibited, with a window for reclaimed and recycled gas until 1 January 2030 on the conditions in that paragraph. Article 13(5): from 1 January 2032 the line drops to 750 for stationary refrigeration equipment, chillers excluded.
An operator planning on a ten- or fifteen-year horizon therefore sees two successive lines cutting away the fluorinated options. R-744 carries none of those dates, because none of them apply to it. In regulatory terms, that is the whole explanation of the switch. For the comparison with fluorinated refrigerants, see the ban timetable and replacing R-404A.
Certificate B: what is examined for CO2
Implementing Regulation (EU) 2024/2215 names the alternative substances directly in its scope. Article 2(1), point (b), covers installation; point (c) covers repair, maintenance or servicing and decommissioning of the equipment listed in Article 1 containing fluorinated greenhouse gases or the alternative substances ammonia (NH3), carbon dioxide (CO2) or hydrocarbons. Article 2(2) extends the same scope to legal persons working for third parties.
Article 3(2), point (c), creates Certificate B: holders may carry out all the activities provided for in Article 2(1) in relation to carbon dioxide. Unlike Certificates A1 and A2, where a charge-size limit appears, the Certificate B text states none.
Annex I sets out the specific content. Heading 13 — installation and good practice of servicing for equipment and systems relying on R744 (CO2) — requires, among other things:
- Knowledge of the requirements for labelling of R744 in systems and in pressure vessels. Labelling does not vanish with Article 12; it changes legal basis.
- Reading and understanding the piping and instrumentation diagrams of refrigeration systems with R744.
- Knowledge of the special requirements for refrigerant cylinders and double valves and for gas extraction.
- Knowledge of the safety requirements for service tools and equipment such as gas detection, leak detection and personal protective equipment.
- Calculation of the charge of R744 in a system according to applicable safety standards.
- A risk analysis before starting the work, preparation of the work area and selection of appropriate tools.
- A pressure test to check the pressure resistance and tightness of the system, then a vacuum test for moisture.
- Safe removal of R744 from the system and charging the system with R744 in gaseous form.
- A leak check by a direct method, and writing the service report.
- Knowledge of the significance of high pressure at the triple point and the formation of dry ice.
- Knowledge of the safety requirements for operating an R744 system, and of energy efficiency measures for higher-pressure refrigerants.
The annex also requires, under system design, knowledge of the differences in components and architecture for R744 systems: requirements for pipework materials, the function of booster systems, medium-pressure and high-pressure control valves, optimisations such as parallel compressors, ejector technology — liquid and gas ejectors — and systems with partial flooding, plus safety concepts for limiting standstill pressure and the use of stagnation cooling systems.
Annex I provides that, for Certificates A1 and A2, at least one of the theoretical questions must relate to the specifics of CO2 and ammonia. That does not replace Certificate B for work on CO2 systems — it only shows that the legislator expects every technician to recognise a high-pressure system when one is in front of them.
For the conditions of the company certificate and the subcontractor check, see the guide on low-GWP refrigerants on site and the certificate categories.
Pressure, cylinders and transport
The practical difference between a CO2 system and an HFC one is not the chemistry, it is the pressure. The figures from the supplier's safety data sheet for carbon dioxide:
| Property | Value from the safety data sheet |
|---|---|
| Vapour pressure at 20 °C | 57.3 bar (absolute) |
| Critical temperature | 31 °C |
| Critical pressure | 7 375 kPa |
| Triple point | −56.6 °C |
| Sublimation at atmospheric pressure | −78.5 °C |
| Flammability | Non-flammable |
| CLP classification | Press. Gas (Liq.), H280; pictogram GHS04; signal word Warning |
The critical temperature of 31 °C explains why commercial CO2 plant runs transcritical on warm days: above that temperature there is no conventional condensation. The triple point explains the second peculiarity: expand below the triple-point pressure and dry ice forms, which is exactly why the certification annex requires knowledge of that phenomenon.
A CO2 system that has stopped warms to ambient, and the pressure rises. Annex I to Implementing Regulation (EU) 2024/2215 requires knowledge of safety concepts for limiting standstill pressure and of stagnation cooling systems. The actual design values come from the manufacturer's documentation, the system standards and pressure equipment law — Directive 2014/68/EU for stationary pressure equipment, Directive 2010/35/EU for transportable pressure equipment. You will not find them in the F-gas Regulation, and you will not find them here.
For transport, the 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 1013, proper shipping name CARBON DIOXIDE, transport hazard class 2.2, non-flammable non-toxic gases. The applicable Union framework is Directive 2008/68/EC, and the thresholds and documentary duties come from there, not from here.
R744 service cylinders frequently carry a double valve, for liquid and gas withdrawal — a requirement Annex I mentions expressly. Check before the job which valve you have and which phase you are drawing. Responsibility in transit is covered in the cylinder transport guide.
The real risk is asphyxiation, not flammability
CO2 is classified A1 in the ISO 817 and ANSI/ASHRAE 34 scheme — lower toxicity, flammability class 1, that is practically non-flammable under most conditions of use. The F-gas Regulation assigns no safety classes; they come from the refrigerant classification standards.
"Lower toxicity" does not mean harmless. The supplier's safety data sheet is blunt on this point:
In high concentrations CO2 causes rapid circulatory insufficiency even at normal levels of oxygen concentration. Symptoms are headache, nausea and vomiting, which may lead to unconsciousness and death. The sheet adds the supplemental statement "asphyxiant in high concentrations", and contact with the liquid may cause cold burns or frostbite.
That is the difference from a simple oxygen-displacing asphyxiant: CO2 acts physiologically, not merely by diluting the air. It is why it carries an occupational exposure limit value while ordinary hydrocarbons carry no comparable one.
| Value | Level | Source named in the sheet |
|---|---|---|
| EU indicative limit value, 8 hours | 5 000 ppm (9 000 mg/m3) | Commission Directive 2006/15/EC |
The gas is heavier than air and collects in low places: cold rooms, service ducts, machinery basements, pipe pits. It is colourless and odourless, and the sheet notes expressly that the odour threshold is no useful warning. Instrumental detection is not a luxury.
What the regulation requires here is not a threshold but a competence: heading 13 of Annex I to Implementing Regulation (EU) 2024/2215 puts on the certified person the knowledge of the safety requirements for gas detection and personal protective equipment, and the on-site check that signs, emergency exits, gas sensors and gas alarms are in place. Alarm thresholds, sensor numbers and sensor placement are set in the system standards and in national rules.
Converting from a fluorinated refrigerant: what is left to close
Recover the old charge through certified persons
Article 8(1) of Regulation (EU) 2024/573 applies to the fluorinated charge you take out, whatever replaces it. Recovered gas may not be used for refilling unless it has been recycled or reclaimed, under Article 8(6).
Complete the equipment record
For as long as the equipment was required to be checked under Article 5(1), the Article 7(1) record is still owed for that period, and Article 7(2) requires it to be kept 5 years, by the operator and by the servicing undertaking alike.
Relabel, or remove the F-gas label
The last subparagraph of Article 12(3) requires products and equipment that have been retrofitted, where the fluorinated greenhouse gases have been changed, to be relabelled with updated information. Equipment that no longer contains a fluorinated gas should not carry a label saying it does.
Check that the team's certification covers the new refrigerant
Certificate A1 or A2 does not cover work on CO2 systems. That needs Certificate B, under Article 3(2), point (c), of Implementing Regulation (EU) 2024/2215.
Confirm the pressure equipment regime of the new plant
The new system works at higher pressures. Design, verification and documentation requirements come from pressure equipment law and the applicable standards, not from the F-gas Regulation.
Redo the room detection and ventilation assessment
A non-flammable but asphyxiating refrigerant with a defined exposure limit changes the room monitoring requirements. Settle them with the system designer and the competent authority.
A conversion is not a drop-in: R-744 needs a different circuit, different pipework materials, different control components and a different safety concept. For the general distinction between a direct replacement and a retrofit, see drop-in or retrofit.
Checklist
- The team holds Certificate B for work on CO2 systemsArticle 3(2), point (c), of Implementing Regulation (EU) 2024/2215. A1 and A2 do not cover CO2.
- 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.
- Room gas detection works and has been checkedHeading 13 of Annex I requires checking signs, emergency exits, gas sensors and gas alarms at the location of the system.
- You know which phase you are drawing and which valve you haveAnnex I mentions expressly the special requirements for refrigerant cylinders, double valves and gas extraction.
- The standstill-pressure limiting concept is known and functionalAnnex I requires knowledge of safety concepts for limiting standstill pressure and of stagnation cooling systems.
- The pressure test checks resistance, not only tightnessHeading 13 frames the test as checking the pressure resistance and the tightness of the system.
- The product safety data sheet is accessibleSections 2 and 9 for hazards and properties, 8 for the exposure limit, 14 for transport.
- If you are coming from a fluorinated system, the old file is closedRecovery under Article 8, record under Article 7, relabelling under Article 12(3).
- The service report is writtenHeading 13 requires it expressly, even though the Article 7 record no longer applies.
Frequently asked questions
Does R-744 consume quota?
No. Article 16(1) applies to hydrofluorocarbons, and Article 3, point (4), defines those as the substances listed in Section 1 of Annex I or mixtures containing them. Carbon dioxide is not among them and does not appear in Annex I.
Does a CO2 system have to be leak-checked?
Not under Article 5(1) of Regulation (EU) 2024/573, which is written for Annex I and Annex II Section 1 gases. Checking tightness remains an examined competence for Certificate B, and concrete requirements may come from the system standards and from national rules.
Which certificate do I need for a transcritical system in a shop?
Certificate B, under Article 3(2), point (c), of Implementing Regulation (EU) 2024/2215. Certificates A1 and A2 cover fluorinated greenhouse gases and hydrocarbons, not CO2.
Can I still use a fluorinated gas in a centralised supermarket system?
Point 6 of Annex IV prohibits, from 1 January 2022, multipack centralised refrigeration systems for commercial use of 40 kW or more containing Annex I gases with a GWP of 150 or more — except in the primary refrigerant circuit of cascade systems, where fluorinated greenhouse gases with a GWP of less than 1 500 may be used. That is precisely the cascade architecture with CO2 on the low-temperature stage.
Why is CO2 missing from the Annex VI table?
The table lists non-fluorinated substances that are given a GWP for mixture calculations. The annex says that for other substances not listed in it a default value of 0 applies. CO2 is the reference point of the whole GWP scale, so it has nothing to contribute to a weighted average.
Is CO2 dangerous if it does not burn?
Yes, by a different mechanism. The supplier's safety data sheet states that in high concentrations it causes rapid circulatory insufficiency even at normal oxygen levels, with headache, nausea and vomiting, which may lead to unconsciousness and death. The EU indicative occupational exposure limit value is 5 000 ppm over 8 hours, under Commission Directive 2006/15/EC.
Does a CO2 cylinder need the F-gas label?
No, because Article 12(1), point (g), covers containers of fluorinated greenhouse gases. What remains is hazard labelling under Regulation (EC) 1272/2008 — H280, pictogram GHS04 — and the requirements for labelling R744 in systems and pressure vessels, which Annex I to the certification regulation puts on the certified person.
Official sources
Articles 3, 4, 5, 6, 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 heading 13 of Annex I. The physical properties, the exposure limit and the transport data come from the supplier's safety data sheet.
Currency of this page and limits of responsibility
R-744 works at high pressures and is asphyxiating in high concentrations, with physiological effects even at normal oxygen levels. This page explains its legal position relative to the F-gas Regulation. It is not a safety procedure, it carries no design pressures, alarm thresholds or charge limits, and it does not replace the manufacturer's documentation, the system standards or national rules. The work is carried out by certified personnel.
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.
Requirements for pressure equipment, stationary and transportable, fall under other acts. Confirm them with the system designer, your supplier and your national competent authority.