If you work in HVAC, refrigeration or vehicle air conditioning in the UK, F-Gas certification is a legal requirement for purchasing and handling most common refrigerants. This guide explains exactly what F-Gas certification is, who needs it, how to get it, and what it allows you to do — updated for 2025.
What Is F-Gas Certification?
F-Gas certification (formally: fluorinated greenhouse gas certification) is a UK government requirement for engineers who work with regulated fluorinated gases (F-Gases). These include virtually all modern refrigerants used in HVAC and refrigeration — R32, R410A, R404A, R134a, R1234yf, R407C and others.
The certification requirement comes from the UK F-Gas Regulation (retained from EU Regulation 517/2014 after Brexit). Under this regulation, it is illegal to:
- Purchase F-Gas refrigerants without valid certification
- Install, service, maintain, repair or decommission equipment containing F-Gases without certification
- Recover, recycle or reclaim F-Gases from equipment without certification
- Check for leaks on equipment containing F-Gases without certification
Enforcement is handled by the Environment Agency in England, NatureScot in Scotland, and NRW in Wales. Penalties for non-compliance can include fines and prosecution.
F-Gas Category I vs Category II: What’s the Difference?
F-Gas certification is split into two categories:
Category I — Stationary Equipment
Category I covers stationary refrigeration, air conditioning and heat pump systems — everything from domestic split AC units and commercial refrigeration to large chillers and industrial cooling systems. This is the certification held by the vast majority of UK HVAC engineers.
Category I certification allows you to:
- Purchase F-Gas refrigerants (R32, R410A, R404A, R407C, R134a, etc.) for stationary applications
- Install, commission, service and decommission stationary AC and refrigeration equipment
- Recover and recharge refrigerant in stationary systems
- Perform leak checks on stationary equipment
Category II — Mobile Air Conditioning
Category II covers mobile air conditioning systems — primarily vehicle AC in cars, vans, trucks, buses and agricultural or construction equipment. Vehicle AC technicians at garages, dealerships and specialist AC workshops typically hold Category II certification.
Category II certification allows you to service and recharge vehicle AC systems and purchase refrigerants for mobile applications (R134a for pre-2017 vehicles; R1234yf for 2017+ vehicles).
Many engineers hold both Category I and Category II to cover stationary and mobile work.
How to Get F-Gas Certified in the UK
F-Gas certification is obtained through ACS (Air Conditioning and Refrigeration) assessments at an approved training and assessment centre. The process:
Step 1: Choose Your Units
ACS qualifications consist of multiple units. For F-Gas Category I, the core units are typically:
- FGAS1 — Safe Handling of Refrigerants (statutory requirement)
- FGAS2 — Recovery/Recycling/Reclaiming F-Gas Refrigerants from Refrigeration Systems
- FGAS3 — Recovery/Recycling/Reclaiming F-Gas Refrigerants from Air Conditioning Systems
For Category II (vehicle AC), the relevant units are assessed separately. Your training centre will advise on the exact units required for your intended scope of work.
Step 2: Find an Approved Assessment Centre
Assessments must be taken at an approved centre registered with an awarding body such as City & Guilds, BPEC or EAL. Find approved centres through:
- REFCOM (refcom.org.uk) — industry certification and register for F-Gas contractors
- ACRIB (acrib.org.uk) — Air Conditioning and Refrigeration Industry Board
- City & Guilds — approved centre search on cityandguilds.com
- BPEC (bpec.org.uk) — Building & Plumbing Engineering Certification
Step 3: Pass Theory and Practical Assessments
ACS assessments consist of written theory tests and practical skills assessments. The practical elements typically cover refrigerant handling, cylinder safety, leak testing procedures and recovery techniques. Most Category I engineers complete the core ACS units in a one-to-two-day intensive assessment at a training centre.
Step 4: Register on the F-Gas Register
Once you pass your ACS assessments, your certification is registered on the official UK F-Gas Register (fgasregister.com). Employers or sole traders can also register their company as an F-Gas Registered Company, which is required for some commercial contracts.
Cost of F-Gas Certification
Costs vary by centre and whether training (not just assessment) is included:
- Assessment only (for experienced engineers): typically £150 — £250 per unit
- Training + assessment (including taught content): typically £250 — £400+ per unit
- Some centres offer bundled packages for multiple ACS units at reduced rates
- Employer funding is common for apprentices and new starters in HVAC businesses
Which Refrigerants Require F-Gas Certification?
All refrigerants regulated under the UK F-Gas Regulation require certification to purchase and handle. This includes the most common UK HVAC and refrigeration gases:
- R32 (GWP 675) — standard for new AC installations
- R410A (GWP 2,088) — service gas for existing AC systems
- R404A (GWP 3,922) — commercial refrigeration service gas
- R407C (GWP 1,774) — R22 retrofit for legacy HVAC systems
- R134a (GWP 1,430) — pre-2017 vehicle AC and commercial refrigeration
- R1234yf (GWP 4) — 2017+ vehicle AC systems
Refrigerant Gas Supplies Ltd supplies all of the above gases exclusively to F-Gas certified engineers and registered companies, based in Wakefield, Yorkshire, with next-day mainland UK delivery.
Frequently Asked Questions
Do I need F-Gas certification to buy refrigerant in the UK?
Yes. UK F-Gas regulations require valid certification to purchase R32, R410A, R404A, R134a, R1234yf and all other regulated F-Gas refrigerants. Refrigerant Gas Supplies Ltd supplies exclusively to F-Gas certified engineers and registered companies.
What is the difference between F-Gas Category I and Category II?
Category I covers stationary refrigeration, AC and heat pump systems. Category II covers mobile AC (vehicle systems). Most HVAC engineers hold Category I; vehicle AC technicians need Category II. Both require passing ACS assessment units at an approved centre.
How long does F-Gas certification take to get?
Core ACS assessment units for Category I can typically be completed in one to two days at an approved centre. Prior HVAC experience is beneficial. Training + assessment courses are available for those newer to the industry.
How much does F-Gas certification cost in the UK?
Assessment-only costs are typically £150–£250 per unit. Training plus assessment courses typically cost £250–£400+. Some employers fund certification for their engineers. Bundled packages for multiple ACS units may offer better value.
Is my F-Gas certification still valid after Brexit?
Yes. UK F-Gas certification remains valid under the retained UK F-Gas Regulation. Note that UK certification is not automatically recognised in EU member states — separate EU certification may be required for work in the EU.