Refrigerant Emissions: The Scope 1 Category Most...

Ask a sustainability lead at any Australian property group, supermarket chain, or cold storage operator to show you their refrigerant emissions number. Watch what happens.

You'll usually get one of three answers. Either a blank look. Or a number that's suspiciously round (1.5% of total Scope 1 is the common fudge). Or a confident figure backed by a single line item from one HVAC contractor for one site.

None of those are right. And under AASB S2 limited assurance, all three will get flagged.

Refrigerant emissions are the Scope 1 category Australian companies underreport most consistently. We see it across construction head contractors, ASX-listed property trusts, food manufacturers, hospitals, and logistics operators. The reasons are structural, not lazy. There's no fuel docket. No utility bill. No monthly invoice that tidily tells you "you released 47 kg of R-410A this quarter."

You have to go looking. And most companies don't, until an auditor asks.

Why the data doesn't show up where everything else does

Every other Scope 1 category has a paper trail that lands in accounts payable. Diesel comes with fuel cards and bowser dockets. Natural gas comes with a quarterly invoice. LPG comes with delivery dockets. The accounting team already has the data, even if it's buried in 10,000 fuel receipts no one wants to type up.

Refrigerants don't work that way. Gas only enters the building when something has gone wrong. A leak. A compressor replacement. An end-of-life retirement. The HVAC contractor turns up, tops up the system, writes a service report, and leaves. The invoice you receive says "service call: $480" with no clue that 3.2 kg of R-134a was added to the chiller.

That service report is the emissions data. It usually doesn't make it to the sustainability team. Often it doesn't even make it to facilities management in a structured form, because the technician hand-wrote the gas type and quantity on a paper docket that got scanned and filed under the asset record.

So when the inventory gets built, refrigerants get a placeholder. Or worse, they get omitted entirely on the assumption that "we'd notice if there was a leak."

What the Australian rules actually require

Two regimes apply here, and they interact in ways that catch people out.

The first is the Ozone Protection and Synthetic Greenhouse Gas Management Act 1989, which implements Australia's obligations under the Montreal Protocol and Kigali Amendment. The Kigali Amendment, in force from 2019, set a global HFC phase-down schedule. Australia's domestic phase-down began in 2018 and steps down HFC bulk import quotas progressively. By 2036, HFC consumption must be 85% below the 2011-2013 baseline. That's not a target. That's a legal quota the Department of Climate Change, Energy, the Environment and Water (DCCEEW) enforces through import permits.

The second is the National Greenhouse and Energy Reporting (NGER) Determination 2008, which is where the emission factors live. The NGER Determination assigns AR5 global warming potentials to each refrigerant species. R-410A sits at 2,088. R-134a at 1,430. R-404A at 3,922. R-407C at 1,774. R-32 (the lower-GWP HFC replacing R-410A in new equipment) at 675.

Then there's AS/NZS 5149.1:2016, which governs refrigeration system safety and underpins how leak detection, charge labelling, and retirement processes get documented in the field. If your contractor is doing the job properly, the data you need already exists. The question is whether anyone is collecting it.

The licensing piece sits with the Australian Refrigeration Council (ARC), which administers refrigerant handling licences and trading authorisations. ARC's database of licensed technicians is the cleanest signal of who is allowed to touch your systems and, by extension, who is generating service records you can pull.

The AR5 vs AR6 gap nobody flagged in time

Here's the part that catches finance teams off guard during AASB S2 readiness.

NGER reporting uses AR5 GWP values. That's locked in legislation. AASB S2 paragraph B19 requires AR6 values for sustainability-related financial disclosures. So if you're a Group 2 entity preparing your first AASB S2 disclosure for FY26-27, your refrigerant emissions number under AASB S2 will be different from the number you submit to the Clean Energy Regulator under NGER, using the same activity data.

The gap isn't trivial for high-GWP HFCs:

Refrigerant	AR5 GWP (NGER)	AR6 GWP (AASB S2)	Delta
R-134a	1,430	1,530	+7.0%
R-410A	2,088	2,256	+8.0%
R-404A	3,922	3,985	+1.6%
R-407C	1,774	1,906	+7.4%
R-32	675	771	+14.2%

For a property portfolio with 500 split systems on R-410A and a 10% annual leak rate, the AR6 restatement adds roughly 8% to your refrigerant Scope 1. For a cold chain operator running R-404A trailers, the delta is smaller in percentage terms but enormous in tonnes CO2-e because the base GWP is already 3,922. We covered the AR5 vs AR6 mechanics in our location vs market-based Scope 2 explainer and the Scope 1 vs 2 vs 3 walkthrough, but refrigerants are where the gap actually bites.

Auditors will ask which version you applied. They'll ask why. And they'll ask whether your prior-year comparatives have been restated. Most companies haven't thought about this yet.

Where the data actually lives

There are four sources. None of them are in your finance system.

Maintenance and service records. Every HVAC service call, every chiller tune-up, every refrigerated transport unit inspection generates a docket. The technician records the refrigerant type, quantity added, and reason. This is the gold standard data source. It's also scattered across contractor portals, paper files, asset management systems, and email inboxes.

Top-up logs. For larger systems, AS/NZS 5149 requires permanent charge labels and (for systems above certain thresholds) logbooks recording every charge addition or removal. Cold storage operators, supermarket chains, and industrial process cooling sites should have these. If they don't, that's a finding before you even start counting emissions.

End-of-life and retirement records. When equipment is decommissioned, the refrigerant either gets recovered (and reported as such by a licensed technician) or it's assumed to have leaked. The end-of-life assumption matters: the NGER Determination's screen/screen-equivalent method assumes 100% of residual charge is emitted unless you can prove recovery. ARC-licensed recovery dockets are the proof.

Bulk purchase records. If you're a large enough operator to buy refrigerant in bulk rather than via per-service top-ups, your purchase records are a reasonable proxy for annual emissions across the fleet. Less granular, but defensible.

The honest reality is that most mid-market companies pull from sources one and four, gloss over two, and ignore three. Group 2 ASRS readiness will force the question.

The screen method nobody applies consistently

NGER offers a "screen" approach for refrigerants under the Determination: annual emissions equal the sum of refrigerant added during the year, plus the residual charge of any equipment retired (less any recovery). It's algebraically simple. It collapses when your asset register doesn't match reality.

We've worked through this with construction head contractors managing temporary site offices, hospitality groups running 40+ venues, and property managers with mixed portfolios. The pattern is always the same: the asset register lists 180 units, facilities know about 220, and the actual count is closer to 260 once you walk the sites. Each unit you missed is a charge you can't account for.

The fix isn't more spreadsheets. It's connecting your asset register to your service record stream so that every refrigerant transaction lands against an identified piece of equipment with a known refrigerant type and nominal charge. If the records don't reconcile, that's the audit signal.

What the cold chain actually looks like

Cold chain operators get hit hardest. A refrigerated trailer running R-404A holds 7 to 10 kg of refrigerant. Industry leak rate assumptions for transport refrigeration units (TRUs) sit between 15% and 25% annually, depending on age and maintenance regime. For a fleet of 80 TRUs at the midpoint:

80 trailers x 8.5 kg average charge x 20% leak rate = 136 kg R-404A
At AR5 GWP 3,922: 533 tCO2-e annually
At AR6 GWP 3,985: 542 tCO2-e annually

That's before you touch warehouse refrigeration. A regional DC running ammonia (R-717, GWP 0) for primary refrigeration and R-449A or R-404A for secondary loops can easily add another 200-400 tCO2-e per site. Multiply across a 15-site network and you're at 5,000-8,000 tCO2-e of refrigerant Scope 1 that often doesn't make it into the inventory. We covered this in more depth in our logistics fleet carbon accounting guide and the food and beverage manufacturing breakdown.

For supermarket retailers, the DCCEEW HFC phase-down is forcing equipment refits anyway. CO2 transcritical systems and propane (R-290) cabinets are replacing HFC racks. The emissions math improves dramatically. The reporting problem doesn't go away, because you still need to account for the old gas that left the system during the refit.

Why most inventories are missing this number entirely

We audited a hypothetical pattern across the work we see. Take a mid-market property manager with 35 commercial sites, mixed retail and office. Roughly 800 HVAC units, ranging from rooftop packaged units on big-box retail to VRV systems on the offices. Mix of R-410A (most units), R-32 (newer Daikin and Mitsubishi installs), R-407C (legacy commercial), and a handful of R-22 systems still limping along despite the HCFC phase-out.

If they only count the refrigerant top-ups invoiced through accounts payable, they'll catch maybe 40% of actual emissions. The rest sits in:

Contractor service portals (Honeywell, Daikin Service, independent operators)
Paper dockets at site
Asset management systems with charge data but no leak tracking
End-of-life replacements where the old unit went to scrap with most of its charge intact

Getting from 40% to 90% coverage is a data collection problem, not a calculation problem. The NGER factors are settled. The AR6 restatement is mechanical. What's hard is finding the dockets.

This is the actual job that we built Carbonly's document AI engine to handle. Service reports, contractor PDFs, asset retirement records, top-up logs (whether they arrive as Excel, scanned PDF, Word doc, or photo) get parsed for refrigerant type, quantity, equipment ID, and date. The material library carries the refrigerant emission factors from the NGA Factors 2025 workbook with both AR5 and AR6 GWP variants, so the same activity data can produce NGER-compliant and AASB S2-compliant numbers from a single source. Source tracking keeps the link from inventory entry back to the original docket, which is what an auditor will ask for. We're not pretending this fixes the asset register reconciliation problem. That's still a walk-the-sites exercise. But it stops the contractor docket pile being the bottleneck.

What to do this quarter

Three concrete actions, in order.

First, pull your refrigerant procurement and service contractor list for the past 12 months. Compare against your asset register. If the contractor count exceeds the asset count, you have unidentified equipment. If the asset count exceeds the contractor count, you have units no one is servicing (which usually means undetected leaks).

Second, request 12 months of service records from every refrigerant contractor in writing. The ARC technician database will help you confirm who's licensed. Service records need to show refrigerant type, quantity added or recovered, equipment ID, date, and technician licence number. If your contractor can't produce these, replace them before AASB S2 assurance season.

Third, run the AR5 vs AR6 reconciliation on whatever number you currently have. Even if it's wrong in absolute terms, knowing the GWP framing gap means you walk into your first AASB S2 disclosure with the right architecture. Our NGER compliance automation post and the AASB S2 disclosure walkthrough cover the dual-reporting plumbing in more detail.

Refrigerants aren't going to be a small Scope 1 line item for much longer. The HFC phase-down is structural. The reporting gap is closing. The auditors are already asking.

The companies that have actual data, not a placeholder, are the ones who won't need to restate.

Refrigerant Emissions: The Scope 1 Category Most Australian Companies Underreport