Chow Line: Think food safety with microwave


Some people at work keep their frozen food entrees in the refrigerator until lunchtime, even though the packages say they should remain frozen until heating. Is this safe?

No, you can’t assume that it is. Frozen food entrees and snack items carry safe food handling and cooking instructions designed to prevent foodborne illness. Consumers should follow these instructions carefully.

Most frozen convenience foods are not ready-to-eat and must be properly cooked first. Some people think freezing food will destroy bacteria that can cause illness, but that’s not true. Freezing temperatures can prevent or slow bacteria from multiplying, but they’re not dead. And they can raise their ugly head when you heat the food and put it in your mouth.

It’s uncommon for frozen foods to be associated with foodborne-illness outbreaks, but it’s been known to happen. In fact, currently there’s a recall in place for Farm Rich, Market Day and Schwan’s frozen food items made at a Rich Products Corporation plant in Georgia during a certain time period due to possible contamination with E. coli O121. As of the end of April, 32 people had become ill, with a third of them hospitalized.

Back in 2010, Marie Callender’s Cheesy Chicken and Rice dinners were associated with a salmonella outbreak. And in 2007, Banquet and store-brand frozen chicken and turkey pot pies made by ConAgra were also linked with salmonella infections.  

To be sure, if you have a food that’s been recalled due to foodborne illness, return it to where you made the purchase or throw it away. Don’t assume you can just cook the heck out of it and be safe. It’s not worth the risk.

But it’s also important to follow cooking instructions for all such products. The Food Safety and Inspection Service offers guidelines at, including:

  • Follow the package instructions. That includes instructions for covering or stirring the food or allowing a “stand time” before eating.
  • Know your microwave oven’s wattage. Cooking instructions are geared to wattage; if your microwave oven has a lower wattage, you’ll need to cook the food longer.
  • Use a food thermometer. Go ahead and test the entree in several places to make sure it’s hot enough -- 165 degrees F. You may need to slide the thermometer in sideways to get a good reading.

Chow Line is a service of Ohio State University Extension, the Ohio Agricultural Research and Development Center, and the College of Food, Agricultural, and Environmental Sciences. Send questions to Chow Line, c/o Martha Filipic, 2021 Coffey Road, Columbus, OH, 43210-1044, or

Editor: This column was reviewed by Linnette Goard, field specialist in Food Safety and Management for Ohio State University Extension, the outreach arm of the College of Food, Agricultural, and Environmental Sciences.

For a PDF of this column, click here.

CFAES News Team
For more information, contact: 

Linnette Goard
OSU Extension, Food Safety and Management