Food safety in emergencies
The danger zone
Critical temperature: 4 °C to 60 °C
The danger zone is between 4 °C and 60 °C. Bacteria multiply rapidly in this temperature range. Perishable foods that remain in this zone for more than 2 hours should be discarded. Do not trust appearance or smell. Many dangerous bacteria do not alter the appearance of food.
Fridge and freezer without power
Fridge
- Maintains safe temperature for up to ~4 hours (if kept closed)
- Each opening reduces the time by ~30 minutes
- Use a fridge thermometer to check (below 4 °C = safe)
- Transfer essential items to a cooler with ice if the outage is prolonged
Freezer
- Full freezer: safe for up to ~48 hours
- Half-full freezer: safe for up to ~24 hours
- Food with ice crystals can be safely refrozen
- Group frozen foods together so they retain cold from each other
Safety table by food type
| Food | Safe without refrigeration | Action |
|---|---|---|
| Raw/cooked meat | 2 hours | Discard if above 4 °C |
| Fish and seafood | 2 hours | Discard if above 4 °C |
| Milk and dairy | 2 hours | Discard if above 4 °C |
| Eggs | 2 hours | Discard if above 4 °C |
| Cut fruits | 2 hours | Discard if above 4 °C |
| Mayonnaise-based sauces | 2 hours | Discard if above 4 °C |
| Tinned food (opened) | 2 hours | Transfer to container and refrigerate |
| Tinned food (sealed) | Several years | Safe (check expiry date) |
| Bread | 3-5 days | Check for mould |
| Whole fruits | Several days | Safe whilst there are no signs of deterioration |
| Peanut butter | Months | Safe |
| Biscuits and cereals | Months | Safe if packaging intact |
| Bottled water | Indefinite | Safe |
Signs of contamination
Strange smell
Unpleasant, sour or abnormal odour. Any unusual smell is sufficient reason to discard.
Altered texture
Slimy, sticky or slippery surface. Meat and dairy are the first to show this sign.
Different colour
Visible change in the food's usual colour. Greenish, greyish or yellowing tones are warning signs.
Swollen packaging
Tins or packaging with internal gases indicate bacterial activity. Never open, discard immediately.
Visible mould
Any presence of mould, even small. It is not enough to remove the affected part, mould roots penetrate the food.
Strange taste
Never taste if there are other signs of contamination. Only check the taste if appearance and smell are normal.
Tinned food: the best option in emergencies
Why they are ideal
- Do not need refrigeration (whilst sealed)
- Shelf life of 2 to 5 years
- Can be consumed cold, if necessary
- Wide variety: tuna, sardines, beans, chickpeas, vegetables, fruit in syrup, soup
How to purify water in an emergency
Boiling
The most reliable method. Boil water for at least 1 minute at a full rolling boil. Allow to cool before consuming. At altitudes above 2000 metres, boil for 3 minutes.
Purification tablets
Follow the manufacturer's instructions. Generally require 30 minutes' wait. Available in pharmacies and camping shops. Practical to include in your emergency kit.
Household bleach
Use bleach without additives (no fragrance or detergent): 2 drops per litre of water. Mix well and wait 30 minutes. The water should have a slight chlorine smell. If not, repeat and wait another 15 minutes.
Floodwater
Never drink floodwater, even after boiling. It may be contaminated with sewage, chemicals and industrial waste that boiling does not eliminate.
Related pages
Food supply
Complete guide to emergency foods, quantities per person and storage tips.
Freezer autonomy
Calculator to estimate how long frozen foods will last without electricity.
Power outages
What to do before, during and after a prolonged blackout.
Medical kit
Emergency pharmacy with essential medicines and dosages.