Bacteria grow most rapidly in the range of temperatures between 40 °F and 140 °F, doubling in number in as little as 20 minutes. This range of temperatures is often called the "Danger Zone." Never leave food out of refrigeration over 2 hours.
Potentially hazardous food needs to be kept at these temperatures to prevent food-poisoning bacteria, which may be present in the food, from multiplying to dangerous levels. These bacteria can grow at temperatures between 5°C and 60°C, which is known as the temperature danger zone.
Food held between 5oC and 60oC for less than 2 hours can be used, sold or put back in the refrigerator to use later. Food held between 5oC and 60oC for 2-4 hours can still be used or sold, but can't be put back in the fridge. Food held between 5oC and 60oC for 4 hours or more must be thrown away.
The temperature range between 5°C and 60°C is known as Temperature Danger Zone. This is because in this zone food poisoning bacteria can grow to unsafe levels that can make you sick.
The 2-hour/4-hour rule provides guidance on how long potentially hazardous food can be held safely at temperatures between 5°C and 60°C (temperature danger zone).
Remember the 2-Hour Rule: Discard any perishables left out at room temperature for more than 2 hours, unless you're keeping it hot or cold. If the buffet is held in a place where the temperature is above 90 °F, the safe holding time is reduced to 1 hour. Watch the clock with leftovers, too!
If in doubt, throw it out!
Throw out high-risk food left in the temperature danger zone for more than 4 hours - don't put it in the fridge and don't keep it for later.
Bacteria can multiply rapidly if left at room temperature or in the “Danger Zone” between 40°F and 140°F. Keep your refrigerator at 40°F or below and your freezer at 0°F or below, and know when to throw food out before it spoils.
Food poisoning bacteria rapidly grows at temperatures between 5°C and 60°C (the temperature danger zone). Minimise the time that food is stored at these temperatures to keep food safe.
High fever (temperature over 102°F) Vomiting so often that you cannot keep liquids down. Signs of dehydration, which include not urinating (peeing) much, a dry mouth and throat, feeling dizzy when standing up.
The 'temperature danger zone' is between 5°C and 60°C, when it is easiest for bacteria to grow.
The 4Cs of food hygiene
Cleaning. Cooking. Chilling. Cross-contamination.
TWO HOURS is the MAXIMUM time perishable foods should be at room temperature (ONE HOUR at temperatures 90 degrees F and higher). This INCLUDES the time they're on the table during your meal. Just ONE bacterium, doubling every 20 minutes, can grow to over 2,097,152 bacteria in 7 hours!
If you reheat previously cooked and cooled potentially hazardous food, you must reheat it rapidly to 60°C or hotter. Ideally, you should aim to reheat food to 60°C within a maximum of two hours to minimise the amount of time that food is at temperatures that favour the growth of bacteria or formation of toxins.
Bacteria are all around us, including those that can cause food poisoning. Food poisoning bacteria grow best at temperatures between 5°C and 60°C. This is called the Temperature Danger Zone. Keeping potentially hazardous foods cold (below 5°C) or hot (above 60°C) stops the bacteria from growing.
The symptoms of food poisoning usually begin within 1 to 2 days of eating contaminated food. They can also start a few hours later or several weeks later.
40-140-4 Rule for Meat
If you are planning to smoke or grill meat, you should know about the 40-140-4 rule; The idea behind this rule is that meat should increase the temperature from 40°F to 140°F within 4 hours. It will reduce the bacteria growth to a great extent.
If high-risk foods have been left in the temperature danger zone for longer than 2 hours, but less than 4 hours, they should be consumed immediately. Throw out any high-risk foods that have been left in the temperature danger zone for more than 4 hours.
Keep the refrigerator temperature at or below 40° F (4° C).
The bacteria that causes food poisoning thrives at temperatures between five and sixty degrees Celsius. It's called the temperature danger zone. So hot food should be kept at 60 degrees or hotter.
Food held between 5°C and 60°C for less than 2 hours can be used, sold or put back in the refrigerator to use later. Food held between 5°C and 60°C for 2-4 hours can still be used or sold, but can't be put back in the fridge. Food held between 5°C and 60°C for 4 hours or more must be thrown away.
Between 2 and 4 hours, the food can still be used, but can't be put back in the refrigerator, and • 4 hours or longer, the food must be thrown out.
Myth: You shouldn't put hot foods in the refrigerator.
If you leave food out to cool and forget about it after 2 hours, throw it away. Bacteria can grow rapidly on food left out at room temperature for more than 2 hours.
Faster is better.
A piece of food will pick up more bacteria the longer it spends on the floor. So food left there for 5 seconds or less will probably collect fewer bacteria than food sitting there for a longer time.