48 people in Minnesota and other states have been stricken by salmonella poisoning in the past 19 months after eating frozen chicken entrees that looked precooked but were raw.

The products, sold in supermarkets, have been marketed as safe for microwaves, but Minnesota health officials say they aren’t, reports the Star Tribune.

Federal regulators had decided in March that the raw-chicken entrees still can be sold as microwave foods. As more people got sick, state officials are urging the U.S. Agriculture Department to ban labeling the foods as microwaveable early last year. They first linked insufficient microwaving of such entrees to another outbreak of salmonella poisoning eight years ago.