Quick answer
Leak checking is an obligation of the operator — and, under Article 5, of the manufacturer — not of whoever happens to service it. How often you must check does not depend on how many kilograms are in the system. It depends on the CO2 equivalent of that charge.
The calculation is short: charge in kilograms × GWP of the gas ÷ 1000 = tonnes of CO2 equivalent. That figure then places the equipment in one of three bands — 12, 6 or 3 months. Fitting a leak detection system doubles the interval in each band.
This matters commercially as well as legally. Two systems holding the same weight of gas can land in different bands, because the gases have different global warming potentials.
Why the interval follows CO2 equivalent, not kilograms
The F-gas rules are built around climate impact, so the yardstick is the warming effect of the charge rather than its mass. A gas with a high global warming potential reaches a given CO2-equivalent threshold with far fewer kilograms than a low-GWP gas.
The practical consequence: you cannot carry a rule of thumb like "over 10 kilos means twice a year" from one refrigerant to another. The band has to be recalculated whenever the gas changes — which is exactly what happens during a retrofit or a drop-in replacement.
After a refrigerant change, the leak check interval frequently changes too, in either direction. Recalculate it as part of the job, before you leave the site.
How to calculate the CO2 equivalent
You need two numbers: the charge in the system, and the global warming potential of the gas in it.
Take the charge in kilograms
Use the actual charge of the system, from the nameplate, the commissioning record or the equipment records. If the system has been topped up or partly recovered, use the current charge, not the original design figure.
Find the GWP of the gas
The binding values are those listed in the Annexes to Regulation (EU) 2024/573. In daily work the same value is printed on the cylinder label and given in section 14 of the safety data sheet. For a blend, use the value for the blend, not for its components.
Multiply, then divide by 1000
Kilograms × GWP gives kilograms of CO2 equivalent. Divide by 1000 to get tonnes. Tonnes of CO2 equivalent is the figure the thresholds are written in.
Write the result down
Record the figure in the equipment records together with the gas and the charge. The next technician on site should not have to redo the calculation to know when the check is due.
GWP values have been revised between versions of the F-gas rules, and blends are frequently confused with their components. Read the value from the Annex, the label or the safety data sheet for the gas actually in the system.
The intervals
For equipment containing gases listed in Annex I, the European Commission sets out the following bands. The right-hand column applies where a leakage detection system is installed.
| Charge | Check every | With leakage detection system |
|---|---|---|
| Under 5 t CO2e | No check required | — |
| 5 to under 50 t CO2e | 12 months | 24 months |
| 50 to under 500 t CO2e | 6 months | 12 months |
| 500 t CO2e and above | 3 months | 6 months |
The bands are cumulative in the obvious way: a system moves up a band as soon as its CO2 equivalent crosses the threshold, whether that happens because the charge was increased or because the gas was changed.
Equipment measured in kilograms instead
Not every gas is handled on the CO2-equivalent scale. For gases listed in Section 1 of Annex II, the Commission expresses the same structure in kilograms.
| Charge | Check every | With leakage detection system |
|---|---|---|
| Under 1 kg | No check required | — |
| 1 to under 10 kg | 12 months | 24 months |
| 10 to under 100 kg | 6 months | 12 months |
| 100 kg and above | 3 months | 6 months |
Check which Annex your gas sits in before applying either table. Using the kilogram table for an Annex I gas will usually understate how often you have to check.
Leakage detection systems: when they are compulsory
Above a certain size a detection system is not a choice. Under Article 6, operators of stationary refrigeration, air-conditioning, heat pump and fire protection equipment holding 500 tonnes of CO2 equivalent or more of Annex I gases — or 100 kg or more of Section 1 Annex II gases — must have a system that alerts the operator or a service company to a leak.
For organic Rankine cycles and electrical switchgear, the same 500-tonne duty applies to equipment installed from 1 January 2017 onwards.
Where a system is installed, the required interval in each band doubles: 12 months becomes 24, 6 becomes 12, and 3 becomes 6. The detection systems themselves also have to be checked regularly.
A detection system reduces how often the check is due. It does not remove the duty to check, to keep records, or to repair what is found.
Equipment that needs no leak check
According to the Commission's obligations pages, no leak check is required for:
- equipment containing gases listed in Annex I below 5 tonnes of CO2 equivalent, or gases in Section 1 of Annex II below 1 kg;
- hermetically sealed equipment below 10 tonnes of CO2 equivalent, or below 2 kg for Section 1 Annex II gases, where the equipment is labelled as hermetically sealed;
- hermetically sealed equipment in residential buildings holding less than 3 kg of fluorinated greenhouse gases;
- electrical switchgear with a tested leakage rate below 0.1 % per year, or holding less than 6 kg of Annex I gases, subject to the conditions in the regulation.
Equipment below the checking thresholds is still subject to the general duty to prevent emissions, to the recovery obligation at end of life, and to the rules on who may work on it.
Who is allowed to carry out the check
Leak checking is not a task anyone on site can sign off. The Commission is explicit that installation, servicing, maintenance, repair, decommissioning and leak checking of this equipment may only be carried out by certified or appropriately qualified persons.
Two separate things have to be in order: the person holds the relevant certificate or training attestation, and, where required, the company holds a company certificate. A certified technician working for an uncertified company does not automatically satisfy the requirement.
The same certification is what allows you to buy refrigerant at all. Distributors may supply fluorinated greenhouse gases only to undertakings holding the relevant certificate or training attestation.
The records that go with the check
The check itself is only half of the obligation. Operators must keep the F-gas records relating to installation and servicing of the equipment for at least five years, including evidence documenting site-specific reasons where an exemption is relied on.
In practice the record should let a competent authority reconstruct, without asking you: which gas is in the system, how much of it, what CO2 equivalent that is, when the last check happened, what was found, what was repaired, and who did the work.
An inspection does not test whether you checked. It tests whether you can show that you checked. An undocumented check counts for nothing.
When the equipment comes out of service
The obligation does not end with checking. Operators must ensure that fluorinated greenhouse gases from decommissioned equipment are recovered, recycled, reclaimed or destroyed.
Venting to atmosphere is not an option, and "the system was already empty" is not a defence that survives a records check. Recovery is carried out by certified persons and is documented like any other intervention.
Common mistakes
- Applying a kilogram rule of thumb to every gas. The band depends on CO2 equivalent; the same weight of two gases can fall in different bands.
- Not recalculating after a retrofit or drop-in. Changing the gas changes the CO2 equivalent and often the interval.
- Using the GWP of a component instead of the blend. For a blend, the value for the blend applies.
- Using the design charge instead of the actual one. After top-ups or partial recovery the figures diverge.
- Assuming a detection system removes the duty. It doubles the interval; nothing more.
- Treating "hermetically sealed" as self-declared. The exemption depends on the equipment being labelled as such and staying within the threshold.
- Doing the check but not recording it. Five years of records is the part that gets inspected.
- Letting an uncertified person carry out or sign off the check. Person and, where required, company both need to be certified.
- Repairing a leak and not verifying the repair. A found leak is the start of the job, not the end of it.
Checklist for the next check
- Actual charge confirmedFrom the nameplate or equipment records, adjusted for any top-up or recovery.
- Correct GWP identifiedFor the gas actually in the system, and for the blend rather than its components.
- CO2 equivalent calculatedKilograms × GWP ÷ 1000, written into the equipment records.
- Correct table usedCO2-equivalent table for Annex I gases, kilogram table for Section 1 Annex II gases.
- Leakage detection system accounted forInterval doubled only where a system is actually installed and working.
- Next due date recordedVisible in the equipment records so the next technician does not have to recalculate.
- Certification in orderThe person holds the relevant certificate, and the company certificate is in place where required.
- Findings and repairs documentedWhat was found, what was done, by whom, and when.
- Records retained for five yearsIncluding the evidence behind any exemption relied on.
Frequently asked questions
Is the interval based on kilograms or on CO2 equivalent?
For gases listed in Annex I it is based on tonnes of CO2 equivalent. For gases in Section 1 of Annex II the Commission expresses the same structure in kilograms. Check which Annex covers your gas before choosing a table.
How do I calculate tonnes of CO2 equivalent?
Multiply the charge in kilograms by the global warming potential of the gas, then divide by 1000. The binding GWP values are those in the Annexes to Regulation (EU) 2024/573; the same figure normally appears on the cylinder label and in section 14 of the safety data sheet.
Does a leak detection system remove the obligation?
No. It doubles the interval in each band — 12 months becomes 24, 6 becomes 12, 3 becomes 6. The duty to check, to keep records and to repair remains.
My system is small. Am I exempt?
Possibly. No check is required below 5 tonnes of CO2 equivalent for Annex I gases, or below 1 kg for Section 1 Annex II gases, with higher thresholds for hermetically sealed equipment and a specific rule for hermetically sealed equipment in residential buildings below 3 kg. Being exempt from checking does not exempt you from the emission-prevention and recovery duties.
Who is responsible — the owner or the service company?
The obligation to have the equipment checked sits with the operator. The work itself must be carried out by certified or appropriately qualified persons, which in practice is usually the servicing company. A service contract does not transfer the operator's legal duty.
Does changing the refrigerant change the interval?
Frequently, yes. A different GWP means a different CO2 equivalent for the same charge, which can move the equipment into another band. Recalculate as part of the retrofit and update the records.
How long do I have to keep the records?
At least five years, including evidence documenting site-specific reasons where an exemption is relied upon.
Do I need a certificate just to buy refrigerant?
Distributors may sell fluorinated greenhouse gases only to undertakings that hold the relevant F-gas certificate or training attestation. In practice you will be asked to evidence it before a supplier will release gas to you.
Official sources
The thresholds, intervals and record-keeping periods in this guide come from the European Commission's own pages on obligations under the F-gas Regulation.
Currency of this guide and limits of responsibility
This guide summarises thresholds and intervals as published by the European Commission on the verification date shown at the top of the page. Where a figure matters commercially or legally, confirm it against the current text of the regulation and the Commission's pages before you act.
This is general information prepared by EgoLog, not legal advice and not a substitute for certification. Deciding which Annex covers your gas, which threshold applies to your installation and what your records must contain remains your responsibility as operator.
Work on equipment containing fluorinated greenhouse gases may only be carried out by certified or appropriately qualified persons. Nothing here should be read as encouragement to work on such equipment without the required certification.