"A deceptive and questionable food technology approved by the U.S. Food & Drug Administration is making its way onto supermarket shelves. Carbon monoxide gas is being used in meat and fish packaging to create a red color typically associated with freshness. CO treatment means that consumers are more likely to eat spoiled meat that looks fresh (ick!).
As all you cooks know, meat not treated with carbon monoxide will begin to turn brown (or naturally oxidize) after approximately 10 to 12 days. But meat treated with carbon monoxide will retain its color and mask spoilage even when improperly stored for weeks at a time. And, the presence of CO can cause fish to accumulate dangerous levels of scombrotoxin or histamine and can mask a wide variety of pathogens in meat including E. Coli and Salmonella."