Almost one in three pre-packed sandwiches are stored or displayed at the wrong temperature, increasing the risk of food poisoning, the Food Safety Authority of Ireland (FSAI) has warned.

The authority has just published a study into the microbiological safety of pre-packed sandwiches. While the findings show that 99% of sandwiches were satisfactory when tested for the foodborne bacteria, Listeria, there was concern over the storage of these food items.

Altogether, 29% of pre-packed sandwiches were being stored or displayed at temperatures higher than five degrees Celsius. Pre-packed sandwiches should be stored at five degrees Celsius or cooler, as this stops or slows down the growth of bacteria.

Meanwhile the study found that four of the five sandwiches, which were classified as unsatisfactory or unacceptable/potentially hazardous, were stored above eight degrees Celsius, with one sandwich displayed unrefrigerated at almost 18 degrees Celsius.

The study involved the testing of 948 pre-packaged sandwiches from retailers and caterers across the country. Sandwiches made to order, unwrapped sandwiches and sandwiches which receive heat-treatment, e.g. toasted sandwiches and paninis. were excluded from study.