Food Standards Scotland (FSS) research has revealed high refrigerator temperatures are putting people at increased risk of foodborne illness.

Despite the recommended operating temperature being between 0 to 5 degrees C (32 to 41 degrees F), the majority of refrigerators monitored in the Fridge Recording Over Set Time (FROST) trial had an average temperature of greater than 41 degrees F.

More than 350 homes across the country participated in FROST, which was conducted between August 2023 and May 2024. Temperature loggers, sent out by FSS, were placed in the participants’ fridge and tracked temperature over two weeks. This was measured every 10 minutes for 10 days using two devices: one on the bottom shelf of the fridge and one on the top shelf.

Results revealed that although the average temperature overall was 5.17 degrees C (41.3 degrees F), individual average fridge temperatures ranged from -0.39 to 10.94 degrees C (31.3 to 51.7 degrees F). Individual readings varied from -11.9 to 19.1 degrees C (10.6 to 66.4 degrees F).

Age of the fridge did not impact temperature, but type did with American-style and free-standing fridges having significantly lower temperatures overall.

important role of the fridge
The top areas of fridges were found to be hotter than the bottom. There were 27 fridges that did not record a single measurement in the recommended temperature range.

Although knowledge of the correct range was high with consumers, this did not translate to behavior with only a few people manually checking fridge temperatures.

Photos revealed examples of people overfilling their fridges, as well as storing high-risk products such as raw meat in the incorrect section. Meat should be stored on the lowest shelf.

Other surveys by FSS have found that people are adjusting their fridge settings to higher temperatures as a way to save money on energy bills.

“There are an estimated 43,000 cases of foodborne illness annually and your fridge can be the first line of defense when keeping food safe. Fridges need to be kept at a temperature between 0 to 5 degrees C to slow the growth of bacteria and keep food fresher and safer for longer but, worryingly, a majority of fridges are not at the correct temperature,” said Dr Louise Crozier, senior scientific adviser at FSS.

“From this research, we know that there is additional work needed to increase consumer awareness on checking fridge temperatures using a fridge thermometer to ensure it is operating between 0 to 5 degrees C and to develop further advice on food placement and storage to minimize the risk of foodborne illness.”

FSS is hosting a webinar on June 18 to share results from the research. Registration details can be found here.