We have all heard of THE RULE: If you drop food on the floor, and you lift it up for 5 seconds or less, it is safe to consume it.



But, is it really so? Bacteria can be transmitted to the food for less than a second, according to the New Jersey University scientists. This depends on the surface where the food fell, and on the food itself as well as the moisture it contains. Therefore, this so-called rule is not scientifically proven and it is only a peoples saying.


All of this was confirmed after an experiment was done with four kinds of food: watermelon, bread, bread with butter and jelly beans. The food was intentionally dropped on surfaces of stainless steel, ceramic tiles, wooden floor and a carpet. All of the situations were done for less than a second, for five seconds, thirty and three hundred seconds.

The surfaces were contaminated with bacteria similar to salmonella. 2.560 tries were conducted on all surfaces, with all time frames.


The watermelon that is almost 90% made of water showed the highest chance to absorb bacteria, and the jelly beans the lowest. Since the bacteria migrate hand in hand with moisture, the watermelon was contaminated in the quickest time frame, and also the watermelon is the biggest of them all.


The surface material matters too – the food that dropped on the carpet had the lowest contamination level, while the food that dropped on the tiles and the steel had a higher contamination level. When it comes to the wooden floor – the parameters varied.