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HFO (unsaturated, single component) · ASHRAE 34 safety group A2L

R-1234yf GWP and CO₂e

2,3,3,3-tetrafluoropropene. Current, very low GWP. Mostly encountered in buildings as the low-GWP half of a blend such as R-454B or R-513A.

Great Britain

4

Retained Regulation (EU) No 517/2014, Annex II (Montreal Protocol SAP 2010)

EU / Northern Ireland

0.501

Regulation (EU) 2024/573, Annex II (AR6 basis, footnote 2)

These two figures genuinely differ. Use the one for the regime the equipment is in — Great Britain, or Northern Ireland under the Windsor Framework.

Charge in kg → tonnes CO₂e

t CO₂e = charge (kg) × GWP ÷ 1,000. This figure, not the charge in kilograms, is what sets the statutory leak-check frequency.

Charget CO₂e (GB)t CO₂e (EU/NI)
1 kg0.000.00
2 kg0.010.00
5 kg0.020.00
10 kg0.040.01
20 kg0.080.01
50 kg0.200.03
100 kg0.400.05

Leak-check thresholds in kg

The regulations set the bands in tonnes CO₂e. Converted to a charge of R-1234yf, the duty starts at these weights.

BandCharge (GB)Charge (EU/NI)Check at leastWith leak detection
≥5 t CO₂e1,250 kg9,980 kgAt least every 12 monthsEvery 24 months
≥50 t CO₂e12,500 kg99,800 kgAt least every 6 monthsEvery 12 months
≥500 t CO₂e125,000 kg998,004 kgAt least every 3 monthsEvery 6 months

Automatic leak detection is mandatory at 500 tonnes CO₂e and above. Hermetically sealed equipment labelled as such is exempt below 10 tonnes CO₂e. Records must be kept for at least five years. Sources: retained Regulation (EU) No 517/2014 Articles 4–6, Regulation (EU) 2024/573 Articles 5–7, and GOV.UK guidance on checking F-gas equipment for leaks.

This is the sharpest divergence between the two regimes, and it is about duties rather than numbers. Retained Regulation (EU) No 517/2014 defines a fluorinated greenhouse gas, at Article 2(1), as one listed in Annex I; R-1234yf sits in its Annex II, headed "subject to reporting". So in Great Britain it attracts no statutory leak-check duty. Regulation (EU) 2024/573 extends leak checks at Article 5(1) to equipment holding 1 kg or more of an Annex II Section 1 substance, so in Northern Ireland the same system is checked at least every 12 months from 1 kg, every 6 months from 10 kg and every 3 months from 100 kg. Recovery, certification and record-keeping duties are a separate question from containment and are not addressed by this page.

Where you meet R-1234yf

  • •Automotive air conditioning
  • •A component of several current commercial blends rather than a common building charge in its own right

Maintenance checklists for plant that runs on it

Chiller maintenance checklistAir-Cooled Chiller maintenance checklist
Work out a specific chargeCompare all 10 refrigerants

Frequently asked questions

What is the GWP of R-1234yf?
It depends which regime you are in. In Great Britain it is 4; in the EU and Northern Ireland it is 0.501. Both are correct — they come from different annexes valuing the same substance on different assessment-report bases, and the page above cites each one.
How do I convert an R-1234yf charge into tonnes CO₂e?
Multiply the charge in kilograms by the GWP and divide by 1,000. A 10 kg charge of R-1234yf is 0.04 tonnes CO₂e in Great Britain and 0.01 tonnes in Northern Ireland. That figure is what sets the statutory leak-check frequency, not the charge in kilograms.
At what charge does R-1234yf need leak checks?
The duty starts at 5 tonnes CO₂e, which for R-1234yf is about 1,250 kg in Great Britain. Six-monthly checks start at 50 tonnes (12,500 kg) and quarterly at 500 tonnes (125,000 kg), where an automatic leak detection system also becomes mandatory. Fitting leak detection doubles the interval at every band. Hermetically sealed equipment labelled as such is exempt below 10 tonnes CO₂e.
Does R-1234yf work differently in Northern Ireland?
This is the sharpest divergence between the two regimes, and it is about duties rather than numbers. Retained Regulation (EU) No 517/2014 defines a fluorinated greenhouse gas, at Article 2(1), as one listed in Annex I; R-1234yf sits in its Annex II, headed "subject to reporting". So in Great Britain it attracts no statutory leak-check duty. Regulation (EU) 2024/573 extends leak checks at Article 5(1) to equipment holding 1 kg or more of an Annex II Section 1 substance, so in Northern Ireland the same system is checked at least every 12 months from 1 kg, every 6 months from 10 kg and every 3 months from 100 kg. Recovery, certification and record-keeping duties are a separate question from containment and are not addressed by this page.
Where is R-1234yf used?
Automotive air conditioning; A component of several current commercial blends rather than a common building charge in its own right. Current, very low GWP. Mostly encountered in buildings as the low-GWP half of a blend such as R-454B or R-513A.