Refrigerant R-404A (HFC blend)

No common refrigerant hits harder than R-404A. At a GWP of 3,943, a single 10 kg leak from a supermarket freezer rack puts nearly 40 tonnes of CO₂-e straight into your Scope 1 footprint — often more than the site’s gas heating and vehicle fuel combined. It is the blend behind most of Australia’s cold chain: supermarket refrigeration, cold storage warehouses, and the refrigeration units bolted to trucks and trailers.

Those are also some of the leakiest applications in the NGA Factors, with transport refrigeration carrying an indicative annual leakage rate of 15.7%. High GWP multiplied by high leak rates is why R-404A tops most refrigerant replacement priority lists. Here is the factor, the calculation, and the comparison.

Quick Verdict

R-404A carries a global warming potential of 3,943 under IPCC AR5 100-year values, as published in Table 11 of the Australian National Greenhouse Accounts Factors 2025 (DCCEEW) — the highest of the common refrigerants. Every kilogram of R-404A leaked equals 3,943 kg CO₂-e, reported under Scope 1 as fugitive emissions by the organisation that owns or controls the equipment. The factor applies to the 2025–26 Australian reporting year for NGER and AASB S2 purposes. R-404A dominates commercial and transport refrigeration — supermarkets, cold storage, refrigerated freight — so retailers, food distributors and logistics operators typically find it among their largest single Scope 1 sources, and the highest-priority candidate for replacement with lower-GWP blends (R-448A, R-449A) or CO₂ (R-744) systems.

How to Calculate R-404A Emissions

Emissions (kg CO₂-e) = Quantity of R-404A leaked (kg) × 3,943

Where top-up records are unavailable, estimate leakage as equipment refrigerant charge × the indicative annual leakage rate from NGA Factors 2025 Table 10 (for example, 15.7% for transport refrigeration).

Worked Example 1: Supermarket refrigeration top-up

A supermarket’s centralised R-404A rack system required 30 kg of top-ups across the reporting year, per contractor invoices. Each kilogram added represents a kilogram leaked:

30 kg × 3,943 = 118,290 kg CO₂-e = 118.29 tonnes CO₂-e (Scope 1)

Worked Example 2: Refrigerated trailer fleet

A cold-chain logistics operator runs 12 refrigerated trailers, each with an R-404A charge of 5 kg (60 kg total). Using the indicative 15.7% annual leakage rate for transport refrigeration:

60 kg × 15.7% = 9.42 kg leaked

9.42 kg × 3,943 = 37,143.06 kg CO₂-e = 37.14 tonnes CO₂-e (Scope 1)

Worked Example 3: Cold storage warehouse

A cold store’s plant room log shows a 4 kg R-404A top-up after a leak repair during the year:

4 kg × 3,943 = 15,772 kg CO₂-e = 15.77 tonnes CO₂-e (Scope 1)

R-404A Compared to Other Common Refrigerants

All GWP values are IPCC AR5 100-year figures from NGA Factors 2025 Table 11:

R-404A’s GWP is more than double R-410A’s and nearly six times R-32’s. The same kilogram of leakage that costs an office 677 kg CO₂-e from a modern split system costs a supermarket 3,943 kg CO₂-e from its freezer rack — which is why the cold chain is where refrigerant management delivers the biggest reductions.

NGER and AASB S2 Reporting

Fugitive R-404A emissions are Scope 1 and must be included in NGER reports where your organisation meets the facility or corporate thresholds, using the AR5 GWP values in the NGA Factors 2025. Under AASB S2, Scope 1 disclosure in your climate statement should identify refrigerant emissions by gas type — for cold-chain operators this is often a material line item, so capturing every top-up through an activity-based emissions calculator keeps the audit trail defensible.