Five-Second Rule Put To The Test

A Chicago microbiologist, Nicholas Aicher, tested the famous "five-second rule" by placing petri dishes on the floor for different lengths of time, from zero to 60 seconds, and then incubating them to observe bacterial growth. Every single dish, including the one that touched the floor for zero seconds, showed microbial growth—debunking the idea that food is safe if picked up quickly. Aicher found similar levels of bacteria at five seconds and one minute, concluding that “whether it’s five seconds or 60, it’ll be nasty either way.” His experiment, shared on TikTok, aimed to highlight the unseen "nastiness" we often overlook.