LETTER : The truth about HFCs

Your article "Gas blow for self-cooling cans" (1 June) could give the wrong impression of the environmental impact of HFC 134a.

HFC 134a was developed as an alternative to CFCs as it does not deplete the ozone layer - without it, UK could not have met its responsibilities agreed under the Montreal Protocol on Substances that Deplete the Ozone Layer. It is also non-flammable, highly energy-efficient and non-toxic. Typically it is used in fridges, air-conditioning systems and in medical aerosols such as asthma inhalers.

While it is true that HFCs have a global warming potential, the Inter Governmental Panel on Climate Change (IPCC) predicts that they are unlikely to contribute more that 1-2 per cent to global warming by 2050. Compare this with the estimated contribution from carbon dioxide which is currently more than 60 per cent of man-made global warming. In the majority of applications, HFC134a is used in equipment where it can be safely contained during its use and recycled afterwards.

It is true that ICI declined to supply HFC 134a to the self-cooling drink cans. ICI has always maintained that HFCs should be used responsibly, in beneficial applications where their properties make them the safest and most acceptable replacement for CFCs. While self-chilling cans are a unique invention, they are inconsistent with this policy.

Richard Longden

ICI Klea, Runcorn, Cheshire