Is it true that... you have five seconds' grace after dropping food on the floor?
Many of us have reassured ourselves with the 'five second rule', but bacteria can transfer almost immediately – and sticks around for hours.
TL;DR
- Bacteria transfer to dropped food happens almost immediately, not after five seconds.
- Wet foods like watermelon transferred bacteria most efficiently to surfaces like tile and steel.
- Contaminated surfaces can transfer bacteria to food dropped hours later, with bacteria persisting for about 24 hours.
- Medical instruments dropped in operating rooms require detergent washing to be safe again.
- Rinsing dropped food with water is not enough to guarantee it is clean and safe to eat.