The demand comes in response to an outbreak of listeria linked to melons from a Colorado farm. As many as 16 people have died and 70 others have been sickened after eating tainted cantaloupes.
Costco now wants the cantaloupe industry to set higher standards for growing, picking and cleaning the melons.
None of the tainted melons were sold in California, but as a precaution, health officials say people should toss any cantaloupes unless they know it came from a safe source.
