Chapter 6 · Food

Food safety after a blackout

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In this section (4)

Before the blackout
During the blackout
How long it lasts
When the power returns: what to keep and what to throw out

This is the most practical use of the chapter for your household. The data come from the USDA and FoodSafety.gov.

Before the blackout

Put an appliance thermometer in the refrigerator and another in the freezer. Refrigerator at 40 °F (4 °C) or below; freezer at 0 °F (−18 °C) or below.
Freeze containers of water, gel packs, or ice: they keep things cold and the melted water is good for drinking.
Group the food in the freezer: it stays cold longer.
Have coolers ready and find out where to buy block ice or dry ice. About 50 pounds (23 kg) of dry ice keeps a full 18-cubic-foot freezer cold for 2 days. Handle it with gloves and in a ventilated place.

During the blackout

Do not open the refrigerator or freezer. Every time you open it, you lose cold.
If the blackout will last more than 4 hours, move the milk, meat, fish, eggs, and leftovers to a cooler with ice.
Note the time the power went out.
Do not leave food outside in the cold or snow: the sun warms it and animals can get to it.

How long it lasts

How long it lasts
Appliance	Safe time with the door closed
Refrigerator	About 4 hours
Full freezer	About 48 hours
Half-full freezer	About 24 hours

Figure 6.1. The refrigerator in a blackout: do not open it. With the door closed, the refrigerator lasts about 4 hours and a full freezer about 48 (24 if half full). — **Figure 6.1.** The refrigerator in a blackout: do not open it. With the door closed, the refrigerator lasts about 4 hours and a full freezer about 48 (24 if half full).

When the power returns: what to keep and what to throw out

Measure the temperature of each food with a food thermometer. Never go by smell or taste: many dangerous bacteria do not change the look of food.
Refrigerated: throw out perishables (meat, poultry, fish, eggs, leftovers, milk, soft cheeses, cut fruit and vegetables, pasta, cooked rice) that were at 40 °F (4 °C) or above for more than 2 hours, or more than 1 hour if the temperature was above 90 °F (32 °C).
Frozen: if they still have ice crystals or are at 40 °F (4 °C) or below, you can refreeze or cook them (they may lose quality).
Ice cream and frozen yogurt that thawed: throw them out.
When in doubt, throw it out.

When the power returns: what to keep and what to throw out
Generally keep (even if it warmed up)	Throw out if more than 2 hr above 40 °F
Hard cheeses (cheddar, Parmesan)	Soft, shredded, or low-fat cheeses
Butter and margarine	Milk, cream, yogurt, sour cream
Whole fresh fruit, whole raw vegetables	Cut fruit and vegetables, prepared salads
Ketchup, mustard, vinegar-based sauces, jams	Meats, cold cuts, sausages, bacon, seafood
Bread, tortillas, cakes without cream filling	Cakes with cream or cheese, custard pies, quiche
—	Eggs and egg dishes

Exception: opened mayonnaise, tartar sauce, and horseradish are thrown out if they spent more than 8 hours above 50 °F (10 °C). Check the full table at foodsafety.gov.