Why 5°C and 60°C
Bacteria don't die at 5°C, they just slow down — below that point most food-poisoning bacteria multiply too slowly to reach dangerous numbers within the life of the food. Above 60°C the reverse happens: it's hot enough that they stop growing and start dying off. Between the two, in the middle of the range and around body temperature, some bacteria can double in number roughly every twenty minutes.
That doubling is what makes the zone dangerous rather than merely untidy. A small number of bacteria on a piece of chicken left out on a warm bench is not a problem at 10am. The same chicken at 2pm can carry a dose that will make someone genuinely ill, with no change in how it looks or smells.
This comes up on the test — and the training that covers it is free to read.
Start the Free TrainingWhich foods it applies to
The danger zone matters for potentially hazardous food — the moist, protein-rich foods bacteria like. That includes raw and cooked meat and poultry, seafood, dairy, eggs and egg products, cooked rice and pasta, cut fruit and salad vegetables, soy products, and anything containing these, such as sandwiches, quiches or curries.
Foods that are dry, very acidic, very salty or very sugary are far less hospitable — dry crackers, uncut whole fruit, sugar and honey aren't in the same category. When you're unsure, treat it as potentially hazardous.
- Raw and cooked meat, poultry and seafood
- Dairy, eggs and anything containing them
- Cooked rice and pasta
- Cut fruit, prepared salads and sandwiches
- Soy products and small goods
Time still counts: the 2-hour / 4-hour rule
Food can't always be at 5°C or 60°C — you have to prep it, plate it and serve it. The 2-hour / 4-hour rule covers that gap, and it counts total time in the zone across the food's whole life, not per occasion.
Under two hours in total, food can go back into the fridge. Between two and four hours, it has to be used or served straight away and can't go back. Past four hours total, it goes in the bin. The total is cumulative, which is why keeping track matters more than any single reading.