The “Five Second Rule” – that it takes about 5 seconds for dropped food to become contaminated – has been much discussed this summer, but the much greater risk from dropping foods onto kitchen work surfaces (or handling food with contaminated hands) have been largely ignored
In a new study, the authors quantified cross-contamination between foods and a variety of common kitchen surface types. To do this, they prepared cultures of the Enterobacter aerogenes and applied them to surfaces such as stainless steel, laminate wood, and carpet. The transfer rates of the bacteria from inoculated surfaces to food products (watermelon, bread, bread with butter and gummy candy) was then calculated. While transfer rates to moister foods was slightly quicker than others, the authors still observed microbial transfer for many food types and surfaces within a second.
Although it tends to be discussed in terms of dropping food on the floor, which is typically perceived as dirty and therefore potentially more dangerous, the research shows how easily bacteria can be transferred from apparently clean but contaminated kitchen work surface (e.g a surface which has been in contact with raw contaminated food) to ready to eat foods