How Fast Does Food Spoil When the Power is Out?
Did you know that a flood, fire, national disaster, or the loss of power from hurricane, winter storms, or earthquakes could jeopardize the safety of your food? Knowing how to determine if food is safe and how to keep food safe will help minimize the potential loss of food and reduce the risk of foodborne illness. This fact sheet will help you make the right decisions for keeping your family safe during an emergency.
Fundamentals of Keeping Food Safe in an Emergency
Meat, poultry, fish, and eggs - to be safe to eat - must be refrigerated at or below 40ºF and if frozen, at or below 0ºF. This is difficult when the power is out.
Keep the refrigerator and freezer doors closed as much as possible to maintain the cold temperature. The refrigerator will keep food safely cold for about 4 hours if it is unopened. A full freezer will hold the temperature for approximately 48 hours (24 hours if it is half full) if the door remains closed. Obtain dry or block ice to keep your refrigerator as cold as possible if the power is going to be out for a prolonged period of time. Fifty pounds of dry ice should hold an 18-cubic foot full freezer for 2 days. Plan ahead and know where dry ice and block ice can be purchased.
Be prepared for an emergency by having items on hand that don’t require refrigeration and can be eaten cold or heated on the outdoor grill. Shelf-stable food, boxed or canned milk, water, and canned goods should be part of a planned emergency food supply. Make sure you have ready-to-use baby formula for infants and pet food. Remember to use these items and replace them from time to time. Be sure to keep a hand-held can opener for an emergency.
Consider what you can do ahead of time to store your food safely in an emergency. If you live in a location that could be affected by a flood, plan your food storage on shelves that will be safely out of the way of contaminated water. Coolers are a great help for keeping food cold if the power will be out for more than 4 hours—have a couple on hand along with frozen gel packs. When your freezer is not full, keep items close together—this helps the food stay cold longer.
Digital, dial, or instant-read food thermometers and appliance thermometers will help you know if the food is at safe temperatures. Keep appliance thermometers in the refrigerator and freezer at all times. When the power is out, an appliance thermometer will always indicate the temperature in the refrigerator and freezer no matter how long the power has been out. The refrigerator temperature should be 40ºF or below; the freezer, 0 ºF or lower. If you’re not sure a particular food is cold enough, take its temperature with a food thermometer.
Frequently Asked Questions:
- Q. Flood waters covered our food stored on shelves and in cabinets. What can I keep and what should I throw out? How should I clean my dishes and pots and pans?
- A. Discard all food that came in contact with flood waters including canned goods. It is impossible to know if containers were damaged and the seal compromised. Discard wooden cutting boards, plastic utensils, baby bottle nipples, and pacifiers. There is no way to safely clean them if they have come in contact with contaminated flood waters. Thoroughly wash metal pans, ceramic dishes, and utensils with hot soapy water and sanitize by boiling them in clean water or by immersing them for 15 minutes in a solution of 1 teaspoon of chlorine bleach per quart of water.
- Q. My home was flooded and I am worried about the safety of the drinking water. What should I do?
- A. Drink only approved or chlorinated water. Consider all water from wells, cisterns, and other delivery systems in the disaster area unsafe until tested. Purchase bottled water, if necessary, until you are certain that your water supply is safe. Keep a three-day supply of water or a minimum of 3 gallons of water per person.
- Q. We had a fire in our home and I am worried about what food I can keep and what to throw away.
- A. Discard food that has been near a fire. Food exposed to fire can be damaged by the heat of the fire, smoke fumes, and chemicals used to fight the fire. Food in cans or jars may appear to be okay, but the heat from a fire can activate food spoilage bacteria. If the heat is extreme, the cans or jars themselves can split or rupture, rendering the food unsafe. One of the most dangerous elements of a fire is sometimes not the fire itself, but toxic fumes released from burning materials. Discard any raw food or food in permeable packaging—cardboard, plastic wrap, screw-topped jars, bottles, etc.—stored outside the refrigerator. Food stored in refrigerators or freezers can also become contaminated by fumes. The refrigerator seal isn't airtight and fumes can get inside. Chemicals used to fight the fire contain toxic materials and can contaminate food and cookware. Food that is exposed to chemicals should be thrown away—the chemicals cannot be washed off the food. This includes food stored at room temperature, such as fruits and vegetables, as well as food stored in permeable containers like cardboard and screw-topped jars and bottles. Cookware exposed to fire-fighting chemicals can be decontaminated by washing in soap and hot water. Then submerge for 15 minutes in a solution of 1 teaspoon chlorine bleach per quart of water.
- Q. A snowstorm knocked down the power lines, can I put the food from the refrigerator and freezer out in the snow?
- A. No, frozen food can thaw if it is exposed to the sun's rays even when the temperature is very cold. Refrigerated food may become too warm and foodborne bacteria could grow. The outside temperature could vary hour by hour and the temperature outside will not protect refrigerated and frozen food. Additionally, perishable items could be exposed to unsanitary conditions or to animals. Animals may harbor bacteria or disease; never consume food that has come in contact with an animal. Rather than putting the food outside, consider taking advantage of the cold temperatures by making ice. Fill buckets, empty milk cartons or cans with water and leave them outside to freeze. Then put the homemade ice in your refrigerator, freezer, or coolers.
- Q. Some of my food in the freezer started to thaw or had thawed when the power came back on. Is the food safe? How long will the food in the refrigerator be safe with the power off?
- A. Never taste food to determine its safety! You will have to evaluate each item separately. If an appliance thermometer was kept in the freezer, read the temperature when the power comes back on. If the appliance thermometer stored in the freezer reads 40 °F or below, the food is safe and may be refrozen. If a thermometer has not been kept in the freezer, check each package of food to determine the safety. Remember you can’t rely on appearance or odor. If the food still contains ice crystals or is 40 °F or below, it is safe to refreeze . Refrigerated food should be safe as long as power is out no more than 4 hours. Keep the door closed as much as possible. Discard any perishable food (such as meat, poultry, fish, eggs, and leftovers) that have been above 40 °F for 2 hours.
- Q. May I refreeze the food in the freezer if it thawed or partially thawed?
- A. Yes, the food may be safely refrozen if the food still contains ice crystals or is at 40 °F or below. You will have to evaluate each item separately. Be sure to discard any items in either the freezer or the refrigerator that have come into contact with raw meat juices. Partial thawing and refreezing may reduce the quality of some food, but the food will remain safe to eat. See the attached charts for specific recommendations.
Refrigerator Foods - When to Save and When to Throw Out?
If your refrigerator has been off for an extended period, the food within may have been above 40 ºF for over two hours. This is the danger zone for most foods, and if you wonder if your food is safe to eat or must be discarded, look at this list below for guidance:
MEAT, POULTRY, SEAFOOD
Almost without exception, discard all meat, poultry, fish or seafood – whether fresh, leftover, or thawing – that has been above 40 ºF for over two hours. This includes meat products such as lunchmeat, hotdogs, sausage and bacon as well as gravy, stuffing, and even pizza with any meat toppings. Discard any chicken or chicken products, canned hams labeled "Keep Refrigerated," and opened canned meats.
Concerning food safety, cheese can be divided into two classes: soft chesses and hard cheeses. Soft cheeses should be discarded if held in the danger zone for two hours or more. Examples include: blue/bleu cheeses, Brie, Camembert, cottage cheese, cream cheese, Edam, low-fat cheeses, Monterey Jack, mozzarella, Muenster, Neufchatel, ricotta, Roquefort, and shredded cheeses.
Hard cheeses are considered safe to eat if held above 40 ºF for over two hours. Examples include: Cheddar, Colby, Grated Parmesan, Parmesan, Processed Cheeses, provolone, and Swiss.
The following milk products should be discarded if held in the danger zone two hours or more: milk, cream, sour cream, buttermilk, evaporated milk, yogurt, and any opened liquid baby formula. Dairy products considered safe are butter, and margarine.
To be on the safe side, discard fresh eggs, eggs hard-cooked in their shell, egg dishes, egg products, and custards and puddings.
CASSEROLES, SOUPS, STEWS
All variations should be discarded.
Most fruits and fruit products will remain safe. Examples include: opened fruit juices and canned fruit, fresh fruit, coconut, raisins, dried fruits, candied fruits, and dates. Cut fruit are the exception, they should be discarded.
SAUCES, SPREADS, JAMS
Items on the safe list include: barbecue sauce, ketchup, mustard, relish, olives, peanut butter, jelly, taco sauce, and vinegar-based salad dressings. A few items have a slightly higher heat tolerance – opened mayonnaise, tartar sauce, and horseradish should be discarded if held above 50 °F for over 8 hrs. The rest of these, however, are more sensitive and the danger zone temperatures truly are dangerous: fish and oyster sauces, Hoisin sauce, opened cream-based dressings, opened spaghetti sauce jars, and Worcestershire sauce.
BREAD, CAKES, COOKIES, PASTA
The safe list includes: breads, cakes, muffins, rolls, quick breads, and breakfast foods –waffles, pancakes, and bagels. The discard list includes: cheesecake, refrigerator biscuits, rolls, and cookie dough, cooked pasta, and pasta salads with mayonnaise or vinaigrette.
Fruit pies are safe, but the following should be discarded: cream filled pastries, and cheese filled, custard, or chiffon pies.
Vegetables that remain safe include: fresh mushrooms, herbs, and raw vegetables. Vegetables that should be discarded include: pre-cut, pre-washed and packaged greens, cooked vegetables, opened vegetable juice, baked potatoes, commercial garlic in oil, and potato salad.
Frozen Foods - When to Save and When to Throw Out?
If your freezer has been off for an extended period, the food within will likely have been warmed above 0ºF, the recommended temperature freezing food. Depending on how warm and for how long, the food may be safely refrozen, with perhaps some loss in flavor and texture, or should be discarded. Look at this list below for guidance:
MEAT, POULTRY, SEAFOOD
Meat, poultry, fish or seafood that still has ice crystals and feels as cold as if refrigerated is safe to refreeze. This includes products such as: beef, veal, lamb, pork, ground meats, poultry and ground poultry. Also safe are variety meats (liver, kidney, heart, chitterlings), and even casseroles, stews, and soups. Fish, shellfish, and breaded seafood products may be refrozen, but there will be some texture and flavor loss.
If any of the above items have been held above 40 ºF for over two hours, they should all be discarded.
Partially thawed milk products are safe to refreeze as long as they are distinctly cold to the touch. This includes: milk, ice cream, frozen yogurt, and cheese (both soft and semi-soft). The latter may lose some texture. More items on the safe list include: hard cheeses, shredded cheeses, casseroles containing milk, cream, eggs, or soft cheeses. Finally, cheesecake is safe to refreeze if only partially thawed, as are eggs (out of their shell) and egg products.
All of the above items must be discarded if held in the danger zone for over two hours, with hard cheeses being the lone exception.
Fruit juices and home or commercially packaged fruit may be refrozen if still cold, although the up-and-down temperature cycle will change the texture and flavor. These items are also generally safe to refreeze even if fully thawed, but trust your nose – if anything smells or looks suspicious, don’t take an unnecessary risk – toss it!
Vegetables and vegetable juices follow a similar pattern to fruit, but are more forgiving of longer warm periods. If still cold, refreeze vegetable juices and home or commercially packaged or blanched vegetables – though the latter may suffer texture and flavor loss. If completely thawed, vegetables can be safely held above 40 ºF for six hours before they must be discarded.
Breads, rolls, muffins, and cakes without custard fillings can be refrozen even if fully thawed. Cakes, pies, and pastries with custard or cheese filling can be refrozen if still cold when power is restored, but they should be discarded if they have spent two hours or more in the danger zone. Pie crusts, commercial and homemade bread dough can be refrozen if still cold, but some quality loss may occur. They may be refrozen if fully thawed, but the loss of quality is considerable.
Flour, cornmeal, nuts, and breakfast items such as waffles, pancakes, and bagels may be refrozen if cold or thawed. Casseroles, including pasta and rice based dishes, may be refrozen if still cold, but should be discarded if held above 40 ºF for over two hours. The same is true for frozen meals, entrees, and specialty items like pizza, sausage and biscuits, meat pies, and convenience foods.