Power out? Here's how long until the food in your fridge is unsafe to eat

We asked a food safety expert for advice

12 March 2019 - 09:58 By Sanet Oberholzer
To prevent your food spoiling, keep the fridge doors closed during load-shedding or a power outage.
To prevent your food spoiling, keep the fridge doors closed during load-shedding or a power outage.
Image: 123RF/Jackf

When a power outage or load-shedding hits, an aspect often overlooked is the food in our fridges and freezers. With no electricity, how long do we have before food spoils and what should we do to avoid food poisoning?

Dr Lucia Anelich, food safety expert and owner of Anelich Consulting, a food safety training and consulting business, says refrigerated food should be safe, as long as the power is out for no more than four hours, and the fridge door is kept closed.

“Perishable foods are the most susceptible to spoilage and possible food safety concerns – examples are fresh meat, poultry, fish, milk, soft cheeses and possibly even leftovers. It is best to discard these foods if the outage is longer than four hours.”

Anelich adds, “Frozen foods will remain frozen for about 48 hours, again, if the freezer door is kept closed. If any perishable foods start to thaw for whatever reason, they cannot be re-frozen and should be cooked as soon as possible.”

Tasting and smelling food is not always a reliable way to determine whether it is safe to keep or eat

She says tasting and smelling food is not always a reliable way to determine whether it is safe to keep or eat.

Considering the cost of food, you might not want to throw it away, however, you cannot necessarily taste or smell when food is unsafe for consumption.

When food smells “off” it is usually spoiled and should not be consumed, however, it is not necessarily unsafe, and food that smells and tastes fine might, in fact, not be.

These measures apply to all food - at home and stocked in supermarkets. Be wary of where you shop and, if they don’t have generators, find out what their policies are for ensuring food is kept safe and consumable.


  • Keep a thermometer in your fridge; fridges should run at no higher than 4°C and should be kept as cold as possible. Keep the doors closed and remember to remove fresh fruit and vegetables that don’t need to be kept cold to avoid them freezing and spoiling.
  • Freeze usually refrigerated items that can be frozen, such as milk; leftovers; fresh meat and poultry; fish etc, which you might not need immediately.
  • During load-shedding, buy smaller quantities of food that needs to be refrigerated or frozen. Buy more non-perishable or longer-life foods, such as canned goods, dried fruit and bread.
  • Even though you may decide to buy less perishable food during load-shedding, a full freezer retains its temperature for longer. If you have few items in the freezer, group what you have close together so they stay cold for longer.
  • It is always advisable to cook food thoroughly, even when there is no load-shedding or power outage.


  • Poultry is a particularly dangerous food when it goes bad. If it looks grey, has a bad or sour smell and feels slimy, it would be better not to eat it.
  • Fish that has not been stored at the correct temperature has a high risk of being contaminated with a toxin produced by bacteria called histamines. This toxin is not destroyed by normal cooking temperatures and might result in food poisoning.
  • Uncooked rice can be contaminated with Bacillus cereus spores, which can cause food poisoning. These spores can live in dry conditions and can survive the cooking process. They grow into bacteria if left standing in warm temperatures, so it’s recommended to keep cooked rice as cold as possible and warm it until it’s steaming hot all the way through when reheating. 


If you’re not home and can’t monitor how long the power has been out, or if you plan on leaving the house for a day or more, here’s a simple trick to help you determine whether the electricity has been off and if your food is safe to eat.

Fill a glass with water, freeze it, place a coin on top, and leave it in the freezer. When you get home, if the coin is where you left it, the power stayed on, or was out for a short period of time, and your food should be safe to eat. If you find the coin at the bottom of the glass, it’s a good indication that your food has defrosted.

Ice floats on water so, should you find the coin somewhere in the middle, you need to make a judgement call. When in doubt, be safe and rather get rid of the questionable food.