The power is off – is your food?
Modern refrigeration systems maintain food at safe temperatures. This helps reduce the growth of bacteria on your food which can lead to food poisoning.
When there is a power outage you need to take extra measures to reduce the risk of food-related illness.
Potentially hazardous foods – food that needs to be kept cold or hot to minimise the growth of bacteria.
When the power cuts off
When a power cut is ongoing (that is, it cuts for more than 4 hours and there is no immediate likelihood of reconnection) food safety becomes an important issue.
Unless cold storage is available within 2 hours of a power cut, all potentially hazardous foods that are stored in refrigerators or chillers need to be:
- placed in alternative cold storage, for example eskies with ice or ice bricks, or family and friend’s fridges
- eaten immediately
- thrown away if another cold storage area is not immediately available.
Time and temperature are the most important measurements used to determine whether food needs to be regarded as potentially unsafe.
The ‘4 hour/2 hour rule’ for safe storage of food
The following actions are recommended for any potentially hazardous food that has been at temperatures between 5 °C and 60 °C for a total of:
- less than 2 hours – refrigerate or use immediately
- longer than 2 hours but less than 4 hours – use immediately
- 4 hours or longer – must be thrown out.
If available, use a watch and a thermometer to follow these time and temperature recommendations.
The advice offered here refers to any or all potentially hazardous food except those normally kept at room temperature.
Important note: If you are unsure about the time that has passed or the temperature your food has been stored at then throwing the food out is the safest option.
Planned power cuts
The day or night before power is cut off, prepare in advance to store your food safely:
- If possible, try to organise alternative refrigerated storage in advance, for example with relatives, friends or neighbours.
- Avoid buying food that needs to be frozen or refrigerated until after the power is restored.
- Adjust the refrigerator to its coldest setting and remove fresh fruit and vegetables to prevent them being damaged. These items can be stored at room temperature.
- Set your freezer to its coldest setting.
- Place ice bricks, or freeze large blocks of ice, in the freezer for later use.
- If you can, freeze some of the items from your fridge for later use. This is a very safe option and is best done well before the power cut.
Sudden or unplanned power cuts
A sudden or unplanned power cut will not allow much time for you to safely store your foods. Your food will remain safe in your refrigerator for 2 hours, but there are some steps you can take:
- If you have sufficient space in the freezer, after 2 hours you should remove foods from the fridge. Place them in the freezer or esky with ice bricks.
- Do not open the freezer door unless necessary, as this will reduce the time the contents will remain frozen.
If your freezer is efficient, and its door seals are in good condition, it can maintain foods in a frozen state for between 1 and 2 and a half days.
- Relatives, friends or neighbours may be able to provide alternative storage.
During power cuts
Food stored in refrigerators
Your food will remain safe in your refrigerator for 2 hours. If it has been more than 4 hours, throw the food out.
Don’t open the fridge door during the power cut, unless necessary.
The best option is to find immediate refrigerated storage or place items in the freezer.
If this is not possible:
- Remove ice bricks from the freezer and place in an esky.
- Remove all meats, poultry, dairy and potentially hazardous food (for example dips, pâté, ham and salami) from the refrigerator and place in esky.
- Place the ice or ice bricks throughout the stored food to prevent hot spots developing. Make sure the lid of the esky has a good seal.
- If the temperature of the food stored in an esky or refrigerator reaches more than 5 °C for less than 2 hours you have 2 options:
- Find alternative refrigeration at less than 5 °C or if available freeze
- use immediately.
Use immediately any food stored in a refrigerator or esky at more than 5 °C for more than 2 hours but less than 4 hours.
Food stored in a refrigerator or esky at more than 5 °C for 4 hours or more should be thrown out.
Food stored in freezers
- Freezers that are in good condition and operate at minus 15 °C or below can keep foods frozen for between 1 and 2 days. If the freezer door is kept shut, a full freezer can keep food frozen for up to 48 hours, while a half full freezer can kept food frozen for 24 hours.
- It is important that the doors of freezers are not opened unless necessary. Opening and closing the doors will reduce the time the contents will remain frozen.
- Remember that some food types, for example ice cream, will become soft and begin to separate long before other foods defrost. Although there is no safety issue, such foods become icy when refrozen and may not be usable after defrosting and refreezing.
- Foods that have partly defrosted or defrosted but remain very cold (5 °C or less) can be refrozen. Note that while there will not be a food safety issue in refreezing defrosted foods, the quality of the food may be slighted deteriorated.
- You have 2 options for food that has been stored in a freezer where the temperature has reached more than 5 °C for up to 2 hours:
- Find alternative refrigeration at less than 5 °C or refreeze.
- Consume immediately.
If your food has been in a freezer where the temperature has reached more than 5 °C for more than 2 hours, but less than 4 hours, it should be consumed immediately.
Food stored in a freezer for more than 4 hours at more than 5 °C should be thrown out.
Disposal of food
When you dispose of food, wrap it in newspaper and place in the rubbish bin. A small volume of food may be safely buried.
Where larger quantities have to be disposed of your local government’s environmental health officer (external site) should be contacted. Without correct disposal, fly breeding may result and increase the risk of the spread of infectious diseases.
Where to get help
If you need further advice or are concerned about the safety of any food you have stored, contact your local government’s environmental health officer.
You can also phone the Environmental Health Directorate Food Unit on 9388 4999.
This document was produced in collaboration with Curtin University of Technology School of Public Health and PathWest Laboratory Medicine WA.
This publication is provided for education and information purposes only. It is not a substitute for professional medical care. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your healthcare professional. Readers should note that over time currency and completeness of the information may change. All users should seek advice from a qualified healthcare professional for a diagnosis and answers to their medical questions.