If this work is successful, it may be possible to achieve important public health benefits just by changing the surface material commonly used in food processing

Professor Bill Keevil, Southampton University

However, at room temperature, copper killed the bacteria in just four hours. Even at cooled temperatures it killed the bacteria in 14 hours.

Professor Bill Keevil, who led the research, is recommending a far wider use of copper to cut the chance of poisoning outbreaks.

Professor Keevil said: "Stainless steel is used throughout the world because of its perceived hygiene and because it always looks like a nice, clean and bright surface.

"But a close look reveals scratches and marks which, on a microscopic scale, are more like valleys for pathogens to get into these crevices and rubbing a cloth or brush across the surface may not be able to get them out."

In 1997 an outbreak of E.coli 0157 in Scotland made 500 ill and killed 20.

Professor Keevil said: ""The research we have already done has shown that E. coli O157 is a very robust pathogen and that very rigorous cleaning techniques are needed to try and keep it out of the food chain.

"The goal is now to find the appropriate copper alloys that are acceptable for food use, easy to maintain, economical to fabricate and which retain the ability to kill bacteria.

"If this work is successful, it may be possible to achieve important public health benefits just by changing the surface material commonly used in food processing."