A Canadian plastics company has developed a cling film with added antibodies which change colour when food is contaminated with bacteria. Made to detect salmonella, campylobacter, E.coli and listeria, developer Toxin Alert hopes food manufacturers and supermarkets will use the wrap to package products and sell it to consumers. Said to cost 25p more than the conventional type, some microbiologists say the wrap will not be sensitive enough to detect the tiny amounts of bacteria it takes to cause food poisoning. They are worried the wrap will give consumers a false sense of security, but concede it could prevent the kind of contamination which causes mass illness and death. {{NEWS }}