knowledge article/ f-gas
Leak checks: how often, in tonnes of CO2 equivalent and in kilograms of HFO.
How often an installation has to be checked for leaks depends on what is in it. For an HFC such as R32 or R134a you convert the charge into tonnes of CO2 equivalent. For an HFO such as R1234yf or R1234ze you simply count kilograms. That is how Article 5 of Regulation (EU) 2024/573, the EU F-gas Regulation, sets it out, in every EU member state.
Below are the two scales, the calculation with examples, what applies to a blend and when hermetically sealed equipment is exempt. The sources are at the bottom.
Want to know it for a single unit? Enter it in the leak check calculator.
This is an explanation, not legal advice. What applies to your installation is in the regulation itself.
who and when/
When the obligation starts.
The obligation lies with the operator: the company that has actual power over the technical functioning of the installation (Article 3, point 5). That is usually your customer. You do the check for them.
The obligation applies to stationary refrigeration, air conditioning and heat pumps with 5 tonnes of CO2 equivalent or more of HFCs, or with 1 kilogram or more of HFOs (Article 5(1) and (2)). The check is done by a technician with a personal certificate (Article 5(3)).
Every installation with a leak check obligation needs records. They show how much and which gas is in it, what has been added or recovered, who did the work with their certificate number, and when it was checked with what result. The operator keeps them for at least five years, and the company doing the work keeps a copy (Article 7).
how often/
Two scales side by side.
Article 5(6) gives two limits at every step: one in tonnes of CO2 equivalent for the HFCs in Annex I, and one in kilograms for the HFOs in Section 1 of Annex II.
The more is in it, the more often you check. With a fixed leak detection system the interval may be twice as long. From 500 tonnes or 100 kilograms of HFO such a system is mandatory, and then you also check the system itself at least every 12 months (Article 6).
| charge | leak check | with a fixed leak detection system |
|---|---|---|
| HFCs, such as R32, R410A and R134a: in tonnes of CO2 equivalent | ||
| below 5 tonnes | no obligation | not applicable |
| 5 to 50 tonnes | every 12 months | 24 months |
| 50 to 500 tonnes | every 6 months | 12 months |
| 500 tonnes or more | every 3 months | 6 months |
| HFOs, such as R1234yf and R1234ze: in kilograms | ||
| below 1 kg | no obligation | not applicable |
| 1 to 10 kg | every 12 months | 24 months |
| 10 to 100 kg | every 6 months | 12 months |
| 100 kg or more | every 3 months | 6 months |
If the refrigerant contains some of both, as R454B does, both scales count and the shortest interval applies.
Article 5(6) of Regulation (EU) 2024/573. The same table is on the page about the F-gas records.
the calculation/
Calculating the CO2 equivalent.
The regulation says it itself: tonnes of CO2 equivalent is the weight of the gas in tonnes, times the GWP (Article 3, point 3). With the charge in kilograms, you therefore divide by a thousand.
You take the GWP from the annexes. HFCs are in Annex I, with R32 at 675 and R134a at 1,430. HFOs are in Annex II, with R1234yf at 0.501 and R1234ze at 1.37. For a blend you calculate the GWP with Annex VI: per substance the weight share times the GWP, and you add those up.
| refrigerant | gwp | source | charge | co2 equivalent | leak check |
|---|---|---|---|---|---|
| R32 | 675 | Annex I | 1.2 kg | 0.81 tonnes | below 5 tonnes: no leak check obligation |
| R32 | 675 | Annex I | 8 kg | 5.4 tonnes | every 12 months |
| R134a | 1,430 | Annex I | 40 kg | 57.2 tonnes | every 6 months |
| R1234ze | 1.37 | Annex II | 12 kg | 0.016 tonnes | every 6 months, because 12 kg of HFO |
| R454B | 465 | blend, Annex VI | 33 kg | 15.35 tonnes | every 6 months, because 10.26 kg of HFO |
Example charges to show the calculation. For R32 the 5 tonne limit lies at just over 7.4 kilograms, for R134a at almost 3.5 kilograms.
blends/
A blend counts on both scales.
R454B is a blend of an HFC and an HFO. IPLO, the Dutch government's information point for environmental law, uses it as an example: 68.9 per cent R32 and 31.1 per cent R1234yf. Take an installation with 33 kilograms.
On the tonnes scale. The GWP under Annex VI is 0.689 × 675 + 0.311 × 0.501 = 465.2. That makes 33 × 465.2 ÷ 1000 = 15.35 tonnes. Between 5 and 50 tonnes: every 12 months.
On the kilogram scale. The HFO part is 33 × 31.1 per cent = 10.26 kilograms. Between 10 and 100 kilograms: every 6 months.
The shortest interval applies, so every six months. IPLO specifically points this out to inspectors: an installation that used to be checked once a year on the CO2 route may now have to be checked more often because of its HFO part.
exception/
Hermetically sealed equipment.
Hermetically sealed means that all parts containing gas are sealed in the factory, by welding, brazing or a similar permanent connection, with a tested leakage rate of less than 3 grams per year (Article 3, point 9). A split system, whose parts you connect on site, is therefore not hermetically sealed.
If the label says hermetically sealed, the unit does not need to be checked for leaks if it contains less than 10 tonnes of CO2 equivalent of HFCs, or less than 2 kilograms of HFO. If it is in a home, the limit is less than 3 kilograms of F-gas (Article 5(1)).
IPLO puts it this way in its table: hermetically sealed from 2 kilograms of HFO, in a home from 3 kilograms.
after a leak/
The follow-up check after a repair.
The operator has any leak that is found repaired without undue delay. After that comes a follow-up check by a certified technician: at the earliest once the installation has run for 24 hours, and in any case within one month of the repair (Article 4(5)).
Checking on the same day is therefore no longer allowed. IPLO lists that as one of the important changes in Article 4.
Which new units may only be placed on the market from 2027 and 2029 with a refrigerant below GWP 150, is in the article on the F-gas bans per year. How to schedule the checks in your maintenance, you can read on the page about maintenance contracts and leak checks.
and Fikst/
Where Fikst works out the interval.
Fikst is software for air conditioning, heat pump and installation companies. The F-gas records are built in, next to your technician's work order. Fikst works out the interval from what is in your register.
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The CO2 equivalent per installation
Fikst calculates the CO2 equivalent per installation from the charge and the GWP. For an HFC it takes the GWP from Annex I, for an HFO the one from Annex II. A blend is calculated with Annex VI.
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Both scales, the shortest interval
The charge goes against the tonnes scale and the HFO part against the kilogram scale. For a blend such as R454B, Fikst calculates with the HFO share, and the shortest interval wins. If you record a leak detection system for the installation, the interval doubles.
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Hermetically sealed only with the label
The exemption only counts if the installation record says that the manufacturer's label states hermetically sealed. Fikst then takes the strictest reading: the unit must stay below every limit that applies to its gas.
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The check schedule
Periodic leak checks, follow-up checks after a leak repair and leak repairs in one list, with what is coming up and what is overdue. If there is no work order for it yet, you create one with the Create work order button.
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When something is missing
Without refrigerant or charge, the obligation shows as unknown, in its own tab of the check schedule, with what you need to add to the installation.
What you keep doing yourself
The charge and the refrigerant are only right if they are entered correctly in your register. Fikst calculates what the regulation says; whether your installation complies remains the responsibility of the operator and of you as the installer.
The F-gas records are included in your subscription. If you work with refrigerant, we switch them on for you during the setup. Read what the F-gas records in Fikst do
Questions about leak checks.
All frequently asked questions about FikstHow do you calculate the CO2 equivalent of a refrigerant?
The charge in kilograms times the GWP, divided by a thousand. That gives you tonnes of CO2 equivalent. An installation with 8 kilograms of R32, GWP 675, comes to 5.4 tonnes. The GWP is in the annexes of Regulation (EU) 2024/573; for a blend you calculate it with Annex VI.
How often does a leak check have to be done?
For HFCs it depends on the tonnes of CO2 equivalent: from 5 tonnes every 12 months, from 50 tonnes every 6 and from 500 tonnes every 3. For HFOs you count kilograms: from 1 kilogram every 12 months, from 10 kilograms every 6 and from 100 kilograms every 3. With a fixed leak detection system the interval may be twice as long.
From how many kilograms of R32 must an installation be checked for leaks?
From 5 tonnes of CO2 equivalent. With a GWP of 675 that is from just over 7.4 kilograms of R32. An installation with 1.2 kilograms of R32 comes to 0.81 tonnes and has no leak check obligation.
Do leak checks also apply to HFOs such as R1234yf and R1234ze?
Yes, from a charge of 1 kilogram. Their GWP is so low that they never count on the tonnes scale, which is why Article 5 has a separate scale in kilograms for HFOs. Hermetically sealed equipment labelled as such is exempt below 2 kilograms of HFO, in a home below 3 kilograms of F-gas.
What do you do with a blend of HFC and HFO, such as R454B?
You put both parts against their own scale and the shortest interval applies. IPLO works it out: 33 kilograms of R454B contains 31.1 per cent HFO, so 10.26 kilograms. That falls between 10 and 100 kilograms, and then the check must be every 6 months, while the tonnes scale comes to 12 months with 15.35 tonnes.
When is the follow-up check after a leak repair due?
At the earliest once the installation has run for 24 hours, and in any case within one month of the repair. A certified technician does that check. Checking on the same day therefore no longer counts.
Does Fikst work out the interval for me?
Yes. Fikst calculates the CO2 equivalent per installation and puts the charge against both scales, including for a blend. The interval goes into the check schedule, and with the Create work order button you put the check on a work order. If the refrigerant or the charge is missing, the obligation shows as unknown, with what is missing.
Sources.
Consulted on 11 October 2026, in the Dutch text of the regulation; the link below goes to the English text of the same regulation. The articles and annexes in the text are those of Regulation (EU) 2024/573.
- Regulation (EU) 2024/573, English text on EUR-Lex: Articles 3, 4, 5, 6 and 7 and Annexes I, II and VI
- IPLO, consequences of the revised F-gas Regulation for environmental agency staff and inspectors (table of leak checks for HFO refrigerants and the R-454B example) (in Dutch)
- IPLO, consequences of the revised F-gas Regulation for owners and operators (in Dutch)
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