Copper proves more stainless less steel

Every food processing company is conscious of hygiene, and all use stainless steel equipment because of its ability to resist contamination.

But according to new research from the University of Southampton, they may eventually have to replace this material with copper alloys. Microbiologist Bill Keevil, who conducted the Southampton research, says that E Coli strains find it much harder to survive on copper than on steel.

Metal surfaces are covered in microscopic scratches that can trap bacteria, Keevil says. He has found that E Coli can survive for up to 34 days in these scratches on a stainless steel surface, whereas on a copper surface they died after four days.

Copper has been known for its antibacterial properties for millennia - the ancient Egyptians transported water through copper plumbing systems for this reason, for example.

However, it may not be suitable for all uses, particularly those involving acidic foods. Keevil is currently investigating the performance of various copper alloys.