The fridge has failed. What can still be sold?

The three time lines

Food Standards Australia New Zealand's 2-hour/4-hour rule is a guide for refrigerated food that has been out of refrigeration, and the agency's table is the rule in full. Read the time as the total time the food has been between 5°C and 60°C.

Three details from FSANZ decide where a real case falls. The time limits take into account the whole time the food has been out of the fridge, including preparation, storage, transport and display. The time between 5°C and 60°C is cumulative, so every period the food has spent there is added up. And the timing starts when the food is taken out of refrigeration, not when it goes back in.

The rule exists because of how food behaves in the band between the two lines: FSANZ says the rule has been scientifically checked and is based on how quickly microorganisms grow in food at temperatures between 5°C and 60°C. Its own instruction when the total is unclear is the plainest line in the whole page: add up all the time periods, and if in doubt, throw it out.

One display case, worked through

Suppose a deli display case is at 4°C when it is closed for the night and is found at 9°C when it is opened the next morning. The failure is the easy part to see. The question the rule asks is how long the food inside has been between 5°C and 60°C, and the steps below are the whole of the arithmetic it needs.

1. The reading at opening is above the food law's 5°C line, so the food in the case is now in the band where microorganisms grow, and the clock is running.
2. The count is not from the moment the fault was noticed, but from the moment the food left refrigeration. The agency says to start timing as soon as the food is taken out of refrigeration, and the limits take in the whole period the food has been out of the fridge.
3. What bounds the count is a record. The last reading at or below the line, with its date and time, is the point the total runs from. The ACT Government's guidance for food businesses is to record the temperature checks, with the date and time they are done and the temperatures measured, and to measure and record the temperatures of food when it arrives.
4. Then the total falls into one of the three bands. Under two hours, the food can be used, sold or put back in the fridge to use later; between two and four hours, it can be used or sold but not put back; over four hours, it cannot be sold and must be thrown away.
5. If the record is missing and the total cannot be shown, the agency's instruction applies rather than a guess: if in doubt, throw it out.

One detail confuses the arithmetic in a useful direction. The NSW Food Authority says a closed refrigerator should keep food cold for four hours, so the clock may not have started at the moment of the fault at all. What decides is the food's own temperature while the case is closed, which is another reason the reading matters more than the event.

The record has one more use. A fixed gauge on the cabinet measures the equipment, not the food, so it can read well while the food it is meant to protect does not; FSANZ says to use a probe thermometer on the food itself, and not to rely on the fixed gauges alone. Measuring several foods in the same unit catches the spots where the temperature is not what the gauge promises.

After a power cut

The NSW Food Authority's advice for households after a power failure begins with the clock rather than the food: it is useful to make a note of the time the power failed. From then on its guidance is to keep the refrigerator door closed as much as possible, because a closed refrigerator should keep food cold for four hours.

Freezers behave differently. The Food Authority says freezers will usually not defrost, and food will not spoil, for at least 24 hours provided the door has been kept shut. If frozen foods have thawed, they should not be refrozen, but kept cold and eaten as soon as possible.

This is state guidance from New South Wales, and it is written for an emergency. It sits comfortably beside the national rule, because both are answering the same question: how long has this food been warm.

Making the rule usable

Everything above turns on one thing a food business controls: whether it can show the time. The rule itself expects a running count. FSANZ suggests writing down each time food is brought out of refrigeration and put back, or displaying food on colour-coded plates so you know when each has to be sold by.

The thermometer is the instrument the record is built from, and the Code requires it: a food business handling potentially hazardous food must have a temperature measuring device that is readily accessible and accurate to within one degree either way. FSANZ's plain version is at least one thermometer somewhere easy to get to, accurate to within 1°C. Records without an accurate thermometer are a diary of assumptions, which is why the two duties sit together.

Cooked food is a different clock

FSANZ is explicit that the 2-hour/4-hour rule is a guide for refrigerated food, and that it is separate from the mandatory two-stage cooling process of Standard 3.2.2 clause 7(3). Food that has been cooled through that two-stage process is safe to store in the fridge to use later; if it is brought back out of refrigeration, the clock starts again and the 2-hour/4-hour guide can be followed from there.

The two rules are easy to confuse because both count hours and both have a line at 5°C. The difference is what is being watched: this rule watches food that was already cold, and the cooling rule watches cooked food on its way down from 60°C. Cooling cooked food takes the second one.

Who to tell

If food safety is in question and a decision has to be checked, the agency to contact is the one named for food businesses: FSANZ's page for regulatory agencies says complaints about food quality, safety or contamination go to your local food regulatory agency, and lists a contact for each state and territory. Three of the entries name the council. In New South Wales, contact the council for the premises for complaints about hygiene and standards at most retail outlets. In Queensland and in Victoria, ask the local council for an environmental health officer.

The repair is a separate question with its own rule, because work on a regulated refrigerant that could cause leakage needs a licence: Who may fix it sets out the licences involved.