The Building Engineering Services Association (BESA) has alerted the industry to the growing safety risks posed by increased use of flammable refrigerant gases in air conditioning and heat pump systems1. Its technical bulletin TB57, published on 26 June 2024 in time for World Refrigeration Day, sets out the risks from R290 (propane) and calls for specialised training for the technicians who handle it1.
BESA states that there are currently no UK regulations governing the purchase and installation of systems using R290 because, as a hydrocarbon, it falls outside the scope of the F-Gas Regulations1. Under new European Union rules, stationary split air conditioning and heat pump equipment with capacities below 12kW will be required to use F-gases with a GWP below 150 from the start of 2027; for larger systems the threshold is 7501. The UK is not bound by that legislation but is expected to adopt the same rules because of its commitments under the Montreal Protocol and Kigali Amendment1.
The bulletin describes R290 as an A3 gas, the highest level of flammability, which could even be ignited by static electricity, and notes a flammability limit of just 1.7%, so that even a very small amount in a room is enough to pose an ignition risk1. BESA acknowledges that R290 is a highly effective refrigerant with low GWP, high heat transfer performance and low-pressure ratios that cause fewer leaks1. It highlights the need for extensive risk assessments for both new and retrofit applications, well ventilated areas around units, full purging before brazing, and some form of leak detection where a system sits in an enclosed area1. Retrofitting R290 into pre-existing installations is a particular area of concern, with the bulletin advising that units be positioned a safe distance from other electrical equipment1.
"It is classed as an A3 gas, which is the highest level of flammability and means it could even be ignited by static electricity."
BESA says propane use is already growing fast and will continue to accelerate in step with the phase down of refrigerant gases with higher global warming potential1. Farrelly said the phase-down and the potential for more stringent future regulations mean more system replacements may have to employ hydrocarbons like R290, posing a challenge where multiple outdoor units are closely mounted together1.
Why it matters for households
A heat pump or air conditioning unit using R290 carries a flammable gas into the home, and the rules that govern who may buy and install such equipment are, on BESA's account, not yet in place in the UK1. The practical questions for a household are therefore about the installation itself: whether the unit is sited with adequate ventilation, whether it sits clear of other electrical equipment, and whether the engineer has training in flammable refrigerants1. BESA's call is for all technicians and engineers working on R290 systems to receive appropriate specialised training for handling flammable refrigerants1. The wider context is the shift away from higher GWP gases, which is what is pushing R290 into smaller systems in the first place1. Households weighing a heat pump against other heating options, or asking what gas a proposed unit contains, can find the refrigerant types and the F-Gas rules set out in the site's guide to heat pump refrigerants.
What happens next
The EU requirement for stationary split air conditioning and heat pump equipment below 12kW to use F-gases with a GWP below 150 begins at the start of 20271. Whether the UK adopts the same rules has not been reported. BESA has not announced a date for any further bulletin or for changes to training requirements1.
Sources1 cited
- Rise of propane sparks safety fears, thebesa.com