You drop a piece of food on the floor. What’s your move? According to the five-second rule, ✋ your food is “safe” if you snatch it up quickly because bacteria need time to transfer... right? In 2016, researchers at Rutgers University put this to the test, studying four different foods (watermelon, bread, buttered bread, and gummy candy) on four different surfaces (stainless steel, ceramic tile, wood, and carpet) for four different time intervals (less than 1 second, 5 seconds, 30 seconds, and 5 minutes).1 They found that while longer contact times resulted in more bacterial transfer, transference took place almost instantaneously. However, the level of bacterial transfer varied depending on the type of food and the surface it was on. Watermelon 🍉 had the highest amount of bacterial transfer, while gummy candy had the least. Researchers attributed this to moisture, suggesting the wet nature of watermelon facilitated bacteria’s ability to relocate. For surfaces, carpet had the lowest transfer compared to tile, steel, and wood, likely because carpet has crevices that harbor bacteria below the food, as opposed to directly touching it. So, while bacteria could make their way onto your food the moment it hits the floor, there are a variety of factors at play affecting how much bacteria are transferring over. And even if they do transfer, they may not necessarily make you sick. We know not all bacteria are pathogenic. In fact, less than 1% are actually harmful to humans. Though, when in doubt, it’s better to be safe (and throw away your food) than sorry. Back to our opening scenario... drop us a 🗑 if you’re tossing it or a 👄 if you’re eating it. • 1 Miranda, R. C., & Schaffner, D. W. (2016). Longer Contact Times Increase Cross-Contamination of Enterobacter aerogenes from Sturfaces to Food. Applied and environmental microbiology, 82(21), 6490–6496. https://doi.org/10.1128/AEM.01838-16