Foams that contain HFCs with GWP of 150 or more except when required to meet national safety standards
Alternative blowing agents, such as hydro-fluoro-olefins (HFOs) , with very-low GWPs, are being introduced as a replacement for HFCs while retaining similar technical and insulation performance. Non-flammable HFO blowing agents have a GWP as low as one, which is equivalent to carbon dioxide.
For the first time, the emergence of HFOs seems to be offering a level of performance which not only allows the replacement of blowing agents with high-GWPs such as HFCs, but also has the potential to replace some elements of the hydrocarbon and CO2-blown sectors, based primarily on improved thermal properties. This is particularly the case in the PU Appliance sector. In practice, blends of HFOs with other blowing agents are likely to be favoured.