Food Safety — When to Keep, When to Toss

After a power outage, flood, or infrastructure failure, contaminated food causes a second wave of illness that compounds the original crisis. The rules below are simple — when in doubt, throw it out.

⚠️ You cannot determine food safety by appearance or smell alone for all pathogens. If the temperature rules have been broken, discard the food regardless of how it looks.

The Fundamental Rules

Rule	Detail
Temperature danger zone	4°C–60°C (40°F–140°F) — bacteria multiply rapidly in this range
The 4-hour rule	Food held in the danger zone for more than 4 hours cumulative should be discarded
The 2-hour rule (hot weather)	If ambient temperature is above 32°C (90°F), reduce to 2 hours
"When in doubt, throw it out"	If you are unsure how long food has been in the danger zone — discard

Fridge — How Long Is Safe Without Power?

Condition	Safe Duration
Fridge door kept closed	Up to 4 hours
Fridge door opened repeatedly	Less than 4 hours
Fridge with ice or ice packs added	Can extend to 6–8 hours
Ambient temperature >32°C	Reduce times by half

What to Keep vs Toss from the Fridge

Safe to Keep (after up to 4 hours without power, if still cold to touch)

Food	Notes
Hard cheeses (cheddar, parmesan, etc.)	Safe for several hours; discard if mould appears
Butter and margarine	Safe for several days at room temperature
Fruit juices (commercially packaged)	Safe
Opened canned fruits and vegetables	Safe if still cold
Fruit and vegetables (whole, uncut)	Generally safe
Vinegar-based condiments (mustard, ketchup)	Safe
Bread, rolls, muffins	Safe
Peanut butter, jam	Safe

Discard If Above 4°C for More Than 4 Hours

Food	Why
Meat, poultry, seafood (cooked or raw)	High risk of salmonella, listeria
Casseroles, stews, soups	Mixed proteins — discard
Milk, cream, soft cheeses	Dairy spoils and supports dangerous bacteria
Custards, puddings, pies	High protein — discard
Cooked pasta and rice	Bacillus cereus risk — often overlooked
Cooked vegetables	Discard if above temperature limit
Opened baby formula	Discard immediately if warm
Eggs (cracked or cooked)	Discard; intact, uncooked eggs in shell can be kept

Freezer — How Long Is Safe Without Power?

Condition	Safe Duration
Full freezer, door closed	48 hours
Half-full freezer, door closed	24 hours
After adding dry ice	Extends duration — 45 kg / 100 lbs dry ice keeps a full freezer safe for 2 days

Food is safe if it still contains ice crystals, or has been held at or below 4°C (40°F). It may be refrozen if still cold; quality may be affected but it is safe.

Food That Is Always Safe Without Refrigeration

Food	Storage
Commercially canned goods (unopened)	Shelf stable for years; check for swelling or rust
Dried goods (rice, pasta, lentils, flour)	Store in sealed containers away from moisture
Sealed packaged crackers and biscuits	Safe at room temperature
Honey	Indefinitely shelf stable
White sugar, salt, vinegar	Indefinitely shelf stable
Instant coffee, tea	Safe
Unopened nut butters	Safe for months
UHT (long-life) milk	Until opened
Dried fruit and nuts	Months if sealed

After a Flood — Additional Rules

Floodwater contaminates food with sewage, chemicals, and pathogens:

Rule	Detail
Discard any food that touched floodwater	Including canned goods with label damage — hard to verify seal integrity
Discard food with unusual odour	Even canned goods — may indicate seal damage
Do not consume tap water	Until authorities confirm it is safe
Exception: commercially canned goods with intact seals	Can be salvaged if metal can is undamaged; remove label; wash and sanitise outside; relabel with marker

Signs of Spoilage — Additional Indicators

Sign	Action
Unusual smell	Discard — even if within time limits
Unusual colour or texture	Discard
Mould on soft foods (bread, soft cheese, yoghurt)	Discard entire item — mould spreads invisibly
Mould on hard cheese	Cut off 2.5 cm / 1 inch around and below the mould — rest is usually safe
Swollen or leaking can	Discard immediately — do not open
Bubbling or foamy liquids	Discard — indicates fermentation

Quick Reference

Question	Answer
How long is fridge food safe without power?	4 hours (door kept closed); 2 hours above 32°C ambient
How long is a full freezer safe?	48 hours (door kept closed)
Food still has ice crystals — safe?	Yes — may refreeze
Fridge food looks and smells fine but was warm	Discard — pathogens have no visible sign
Touched floodwater — safe?	No — discard even sealed cans unless metal is intact
When in doubt	Throw it out