Emergencies typically happen in the middle of normal life, without warning, so you’ll probably have perishable food in your fridge and freezer that may still be edible if the power goes out. Obviously, you’ll want to eat that stuff first, but how do you know if it’s still good?
Think ahead: before disaster strikes, freeze a jar of water and put a coin on top of the ice. If your power goes out and you’re not sure how long it’s been out, check the coin in the jar. If the coin is where you left it, the ice stayed frozen, which means that your food did too. But if the coin is at the bottom of the jar, even if the water has re-frozen, it means the power was out long enough for the water to melt. That means your food didn’t stay frozen either, so it’s not safe to eat.
If you know when the power went out, set a timer for four hours from the blackout. That’s how long your fridge will stay cold enough to preserve your food, as long as you don’t open it. If you’re not sure, check your refrigerator’s thermometer. It will still keep working even without power, and as long as it’s below 40 degrees Fahrenheit, the food is safe to eat. Try to avoid opening the fridge as much as possible to keep the cold air in, and store food closer together to help it stay cold longer.
It’s a good idea to know where to buy dry ice in case of a power outage, because 25 pounds of dry ice can keep your fridge cold enough for food preservation for two to four days. Just make sure to use thick gloves when handling dry ice, and keep your vehicle well ventilated when transporting it.
Emergency food safety isn’t limited to items in your fridge and freezer—despite the name, nonperishable food can also perish, and you can too from eating it if you’re not careful. Don’t eat food from cans that are damaged (rusted, swollen, dented, etc.) even if the food inside looks okay. Store all your food in airtight containers to keep it safe from rodents and other pests. Dry canned food will be good for only 10–15 days after it’s been opened.
If your home has been impacted by a flood, anything that has come into contact with floodwaters should be tossed out, with the exception of undamaged commercially-canned food. But before you eat anything from these cans, you should thoroughly disinfect them by washing with warm water and soap and then either putting them in boiling water for two minutes or sanitizing them with a bleach and water solution for fifteen minutes. Eat the food in these cans as soon as possible.
Fires pose their own food hazards, as dangerous fumes can poison food, even if it’s been stored in a fridge or freezer. If you’ve had a fire, it’s best to discard any food that could have been affected.
The best rule of thumb for food safety? “When in doubt, throw it out.” Food poisoning is a far riskier proposition than hunger, so always play it safe and ditch any food that is questionable.