OMAHA, Neb. — Zapping frozen meals in the microwave might be fast and easy, but it also can make you sick if it's not done properly.
That message has been slow to catch on, despite a spate of illnesses last year from improperly microwaved frozen foods. On Sunday, the government issued a new warning urging consumers to thoroughly cook frozen chicken dinners after 32 people in 12 states were sickened with salmonella poisoning.
"Given how people use microwaves, it's great for reheating but maybe not so good for cooking," said Doug Powell, scientific director of the International Food Safety Network based at Kansas State University.
The problem is that microwaves heat unevenly, and they can leave cold spots in the food that harbor dangerous bacteria, such as E. coli, salmonella or listeria. So microwaving anything that includes raw meat, whether it's frozen or thawed, can cause problems.
"I think most food-safety experts probably would have said it's not a good idea to microwave anything that's from a raw state," said Michael Davidson, a University of Tennessee food microbiologist.
Many people wrongly assume all frozen meals are precooked and need only to be warmed. It's a misconception fostered in part by foods prepared to appear cooked, such as chicken that has been breaded or pre-browned.
"I haven't worried about the safety of frozen food. Maybe I should," Kathy Tewhill said while perusing the frozen food aisle of a grocery store in Omaha.
In reality, even some meals designed to be microwaved can be unsafe if they are not heated thoroughly enough or are cooked using directions meant for a microwave with different voltage.
The government doesn't track microwave-related food-borne illnesses, but every year, more than 325,000 people are hospitalized for food-related illnesses.