World Ozone Day 2026: F-Gases, Refrigerants and the Emissions Most Corporate Inventories Miss

Ten kilograms of R-404A refrigerant leaking from a supermarket chiller is roughly 39 tonnes of carbon dioxide equivalent. That is a rounding error on a maintenance invoice and a material line in a greenhouse gas inventory, and most companies capture the invoice while missing the emissions entirely.

World Ozone Day falls on 16 September, marking the anniversary of the Montreal Protocol signed in 1987. It is routinely described as the most successful environmental treaty ever agreed, and the description holds. It is also the origin of a problem that corporate reporting has not caught up with, because the chemicals brought in to replace ozone-depleting substances turned out to be extremely potent greenhouse gases.

Here is what the current rules require, why refrigerant emissions escape so many inventories, and how to bring them in properly.

Why The Anniversary Matters

The Montreal Protocol phased out chlorofluorocarbons and other ozone-depleting substances, and it worked. The ozone layer is recovering.

The substitution created a second problem. Hydrofluorocarbons do not deplete ozone, which is why they were adopted, but many carry global warming potentials in the thousands. R-404A sits at 3,922 and R-507A at 3,985, meaning a kilogram of either warms the atmosphere several thousand times more than a kilogram of carbon dioxide.

The Kigali Amendment, agreed in 2016, extended the Protocol to address this by committing parties to phase down HFC production and consumption. It is the mechanism through which an ozone treaty became a climate treaty.

The results are measurable. The HFC phase-out has cut EU F-gas emissions by around 33 per cent as of 2023, following a peak in 2014, and in 2024 EU-27 HFC consumption sat 60 per cent below the Montreal Protocol target recalculated to the EU-27 geographic scope.

What The Rules Require Now

Regulation (EU) 2024/573 is the operative European instrument. Adopted on 7 February 2024, it entered into force and applied from 11 March 2024, replacing Regulation (EU) No 517/2014. It covers hydrofluorocarbons, perfluorocarbons, sulphur hexafluoride, nitrogen trifluoride and a wider set of fluorinated substances listed in its annexes.

The phase-down is aggressive. Bulk HFC supply falls from a 2015 baseline to zero placing on market by 1 January 2050, with stepped reductions in 2025, 2027, 2030, 2033, 2036, 2039, 2042, 2045 and 2048. EU production is separately capped, with producers receiving rights equivalent to 60 per cent of their average annual 2011 to 2013 production from 2025, declining to 15 per cent by 2036.

The quota is measured in carbon dioxide equivalent, not mass. This is the design feature that matters commercially. A tonne of high-GWP refrigerant consumes far more quota than a tonne of low-GWP refrigerant, so the market squeezes the worst gases first. Supply of R-404A and similar products tightens faster than the headline percentages suggest, and prices rise accordingly.

2026 brought further tightening. Additional prohibitions apply to F-gas equipment, products and uses. Emission prevention rules now cover additional equipment and gases, with measures extended to prevent leakage during transportation, installation, servicing and disposal of equipment, products and certain building foams. Enforcement against illegal HFC imports has been strengthened through digitalisation and electronic customs controls.

Leak checking frequency scales with charge size, measured in carbon dioxide equivalent rather than kilograms. Equipment at or above 5 tonnes carbon dioxide equivalent requires checks at least every twelve months, at or above 50 tonnes at least every six months, and larger systems more frequently still. Only certified personnel may handle F-gases, and detailed records of all handling activity must be kept.

Great Britain diverges. Following Brexit, Great Britain operates under retained F-gas law that largely mirrors the original 2014 regulation rather than the 2024 version, and is subject to its own updates. A business operating across both markets cannot assume a single compliance position.

Refrigerant Leakage Is A Scope 1 Emission

This is the accounting point, and it is unambiguous.

Refrigerant that escapes from equipment you own or control is a direct emission from a source you own or control. It is Scope 1, categorised as a fugitive emission, in exactly the same category as gas combustion or vehicle fuel.

It is not Scope 2, because it has nothing to do with purchased energy. It is not Scope 3, because the leak occurs in your own operations. Companies that have placed refrigerants in Scope 3 alongside purchased goods have mislocated them, usually because the refrigerant was bought from a supplier and the purchase looked like a procurement event rather than an emission.

Emissions arise at three points in the equipment lifecycle: initial charging at installation, ongoing leakage during operation, and losses at servicing and end-of-life disposal. All three belong in the inventory.

Why Inventories Miss Them

Five reasons recur, and understanding them tells you where to look.

No meter, no bill. Electricity and gas arrive with invoices that land in finance and flow naturally into an inventory. Refrigerant leaks silently. Nothing arrives to tell you it happened, and the top-up purchase may be buried in a maintenance charge.

The data sits with facilities, not sustainability. Refrigerant records live with facilities management, engineering teams or outsourced maintenance contractors. Sustainability teams frequently have no visibility and, in many organisations, no established route to request it.

No equipment register. Many companies cannot produce a complete list of refrigeration, air conditioning, heat pump, chiller, switchgear and fire suppression assets, with refrigerant type and charge size for each. Without that register the calculation cannot be performed at all.

Outsourced servicing breaks the trail. Where a contractor performs the top-up, the record of how much refrigerant was added sits in the contractor's system. The invoice may show a service visit and a total cost without specifying quantity or gas type.

Materiality thresholds applied by mass. A company screening its inventory by physical quantity will dismiss a few kilograms of gas as immaterial. Screened by carbon dioxide equivalent, the same quantity can exceed an entire vehicle fleet.

That last point deserves the arithmetic. Ten kilograms of R-404A at a GWP of 3,922 is approximately 39 tonnes of carbon dioxide equivalent. For many mid-sized service businesses, a handful of leaking units represents a larger Scope 1 line than the company car fleet.

How To Calculate Properly

Three approaches are recognised, and they differ substantially in accuracy.

The screening method applies default leak rates by equipment type to the installed charge. It requires only an equipment register and is the right starting point where no servicing data exists. It is also the least accurate, and an assurance provider will treat it as an estimate requiring disclosure as such.

The material balance method calculates emissions from refrigerant purchases and disposals, adjusted for changes in stock and in the total charge of installed equipment. In practice, the refrigerant you bought that is not in your equipment and not in your store has leaked. This is the most commonly used approach and it depends entirely on complete purchase and servicing records.

Direct measurement or the simplified material balance at equipment level offers the highest accuracy and requires servicing records per unit.

Whichever method you use, three principles apply. Capture all three lifecycle stages, not only operational leakage. Record the refrigerant type for every unit, since GWPs differ by orders of magnitude and using a generic factor produces a meaningless number. And document the method and its assumptions, because refrigerant emissions are a frequent target of assurance enquiry precisely because the data is so often weak.

The GWP Basis Trap

One technical point catches out companies operating across compliance and reporting.

The F-Gas Regulation specifies GWP values in its own annexes for regulatory purposes, including quota calculation and leak check thresholds. Greenhouse gas inventories typically apply GWP values from a specified IPCC assessment report, and the figure for a given refrigerant differs between assessment reports.

The consequence is that the same leak can legitimately produce two different carbon dioxide equivalent figures, one for F-gas compliance and one for your inventory. Neither is wrong. What is wrong is mixing them, or failing to state which basis you used.

State the GWP basis explicitly in your inventory methodology, apply it consistently across all refrigerants, and keep the regulatory calculation separate from the reporting calculation.

Practical Steps

Build the equipment register first. Every refrigeration, air conditioning, heat pump, chiller, switchgear and fire suppression asset, with location, refrigerant type, charge size in kilograms and installation date. Nothing else is possible without it, and it also drives your leak check obligations, which are determined by charge size in carbon dioxide equivalent.

Get servicing data from your contractors contractually. Add a requirement to maintenance contracts that refrigerant additions be reported by unit, gas type and quantity. This is a straightforward contract amendment that most contractors can accommodate, and it converts an estimated inventory line into a measured one.

Check where refrigerants currently sit in your inventory. If they are in Scope 3, or absent, that is a correction to make before assurance rather than during it.

Screen by carbon dioxide equivalent, never by mass. Apply your materiality threshold to the converted figure.

Map the phase-down against your equipment. Assets running on high-GWP refrigerants face rising costs and eventual supply constraints as the quota tightens. A chiller installed today on R-404A is a stranded asset risk on a known timetable, and the replacement decision should be made against the phase-down schedule rather than the maintenance cycle.

Treat refrigerant transition as a decarbonisation lever. Switching to low-GWP alternatives reduces Scope 1 emissions directly and durably, which is unusual. Most Scope 1 reduction requires operational change or capital-intensive fuel switching, whereas refrigerant substitution happens at equipment replacement that is occurring anyway.

Do not overlook non-cooling F-gases. Sulphur hexafluoride in electrical switchgear carries an extremely high GWP, and fire suppression systems and insulating foams also contain fluorinated gases. These are outside the refrigeration workflow and are missed even more often.

The Broader Point

The Montreal Protocol is the strongest available evidence that coordinated international environmental regulation can work at scale. Thirty nine years on, the ozone layer is recovering and the phase-down of its successor chemicals is measurably reducing emissions.

The corporate reporting gap is unusual because it is not a data availability problem. The information exists, in maintenance records and equipment registers, and the calculation methods are well established. It is an organisational problem: the data sits in a function that does not report emissions, and the quantities look trivial until they are converted.

For most companies this is a few weeks of work producing a materially more complete Scope 1 inventory, plus a decarbonisation lever that pays for itself at the next equipment replacement. It is one of the few remaining areas where the reporting improvement and the emissions reduction genuinely point the same way.

Inventory Checklist

1. Compile a complete equipment register covering refrigeration, air conditioning, heat pumps, chillers, switchgear and fire suppression, with refrigerant type and charge size per unit.

2. Confirm refrigerant emissions are classified as Scope 1 fugitive emissions, not Scope 2 or Scope 3.

3. Capture all three lifecycle stages: installation charging, operational leakage, and servicing and disposal losses.

4. Choose a calculation method deliberately between screening, material balance and direct measurement, and document which you used.

5. Record the refrigerant type for every unit rather than applying a generic emission factor.

6. State your GWP basis explicitly and apply it consistently, keeping it separate from the F-Gas Regulation values used for compliance.

7. Amend maintenance contracts to require reporting of refrigerant additions by unit, gas type and quantity.

8. Apply materiality thresholds by carbon dioxide equivalent, never by mass.

9. Confirm leak check frequency against charge size in carbon dioxide equivalent, at least annually above 5 tonnes and at least six-monthly above 50 tonnes.

10. Verify that only certified personnel handle F-gases and that handling records are retained.

11. Map assets running high-GWP refrigerants against the phase-down schedule, noting stepped reductions from 2025 through to zero placing on market by 2050.

12. Include sulphur hexafluoride in switchgear, fire suppression agents and insulating foams, which sit outside the refrigeration workflow.

13. If operating in Great Britain as well as the EU, apply the retained F-gas framework separately rather than assuming alignment.

14. Treat refrigerant substitution as a Scope 1 reduction lever aligned to existing equipment replacement cycles.

Position as of September 2026. Regulation (EU) 2024/573 applies from 11 March 2024 with phased provisions running to 2050, and Great Britain operates a separate retained framework. Specific GWP values, quota steps, prohibition dates and leak check thresholds should be confirmed against the regulation annexes. Confirm current requirements with your national competent authority and take professional advice for your circumstances.

Sources

Montreal Protocol on Substances that Deplete the Ozone Layer, Kigali Amendment to the Montreal Protocol, Regulation (EU), European Environment Agency, United Nations Environment Programme Ozone Secretariat, European Fluorocarbons Technical Committee, Daikin Europe, Infraserv

This article is intended for general professional information and does not constitute legal, financial, or investment advice.