COLUMBUS, Ohio -- Anyone experiencing long-term power outages should throw out any refrigerated or frozen foods if they're not certain of their safety, said an Ohio State University Extension food safety field specialist.
Linnette Goard, OSU Extension field specialist in food safety, selection and management, said determining whether perishable foods are safe after a power outage can involve some guesswork. But the rule of "when in doubt, throw it out" stands.
"For many people, it's difficult to throw away food if it's not crystal clear that it's been spoiled," Goard said. "If there's a strange odor, definitely throw it away. But sometimes there's no outward sign that food has gone bad, especially if it's been thawed then refrozen before it's checked.
"If there's any chance that a perishable food has gotten to above 40 degrees Fahrenheit for two hours or more, then it's been in the 'danger zone' too long and should be discarded."
That's especially true for households with people at high risk for severe illness from foodborne disease, including children; pregnant women; the elderly; and people with diabetes or other chronic health conditions.
It's not always easy to tell how long a refrigerator or freezer compartment has been too warm, Goard said.
But a sure sign that a freezer has reached temperatures above 32 degrees F is if ice cubes have melted. That's obvious in freezers that have storage containers for loose ice cubes; they would refreeze into a large sheet. Homeowners who just have ice cube trays (in which the ice would refreeze into cubes) should get in the habit of keeping a few cubes in a zip-close bag in the freezer to make it easier to tell if the compartment has reached above freezing during an outage, she said.
In addition, it's important to know that if foods have been in the danger zone for two hours or more, even cooking them thoroughly won't kill all pathogens that could cause foodborne illness. At those temperatures, pathogens can multiply rapidly, and some produce toxins or spores that remain in the food even after it is cooked.
An OSU Extension fact sheet, "Attention Freezer Owners: In Case of Power Outage, Do Not Open" is downloadable from http://go.osu.edu/powerout. Another resource, "Safe Food Handling During Power Outages" from University of Illinois Extension is available at http://web.extension.illinois.edu/disaster/facts/food.html.
They offer guidelines, including:
- When the power is out, keep refrigerator and freezer doors closed to keep the cold in.
- Food in chest-type freezers that are full or nearly full will keep for 24 hours or longer if the door is not opened. For long-term power outages, try using dry ice to keep food frozen: Twenty-five pounds of dry ice should hold a 10-cubic foot full freezer for two to four days.
- Generally, it is safe to refreeze foods that still contain ice crystals, although quality might be affected.
- If frozen foods have partially thawed, they may or may not be able to be refrozen. Uncooked meat and poultry can be refrozen if odor is normal; fish, shellfish, casseroles and other combination dishes should not be refrozen.
Both Ohio's and Illinois' fact sheets include charts with more details.
In addition, consumers with questions may contact Ohio State's Food Safety Hotline at 1-800-752-2751 (toll free in Ohio), 8 a.m. to 5 p.m. Monday through Friday except for holidays. If there's no response, leave a message and someone will respond within 24 hours on weekdays.
Email messages with food safety questions can also be sent to food safety experts at Ohio State at foodsafety@osu.edu.
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Editor: Linnette Goard is currently out of state for the holiday. For follow-up comments, contact Julie Kennel, nutrition program specialist for Ohio State University Extension and director of the Dietetic Internship Program in the Department of Human Nutrition in the College of Education and Human Ecology, at kennel.3@osu.edu