Everyone knows about the five second rule--the idea that if you drop your food on the floor, it's still safe to eat if you pick it up before five seconds have passed. Now, there may just be scientific evidence that supports this "rule." Researchers have clocked the transfer of two common disease-producing bacteria in order to test whether or not the five-second rule actually holds.

The scientists examined the time it took E. coli and Staphylococcus aureus to transfer from the floor to food. These food items included toast, pasta, biscuit, ham, dried fruit and a sticky dessert, according to the NY Daily News. Contact time lasted between 3 and 30 seconds.

So what did they find? It turns out that time is a significant factor when it comes to the transfer of bacteria from the floor to your food. In addition, the type of floor has an effect; so dropping your food on the carpet is different from dropping it on the kitchen floor. Yet this also means that the five second rule may actually hold in some cases.

"Consuming food dropped on the floor still carries an infection risk as it very much depends on which bacteria are present on the floor at the time," said Anthony Hilton, one of the researchers, in an interview with ScienceDaily. "However the findings of this study will bring some light relief to those who have been employing the five-second rule for years, despite a general consensus that it is purely a myth. We have found evidence that the transfer from indoor flooring surfaces is incredibly poor with carpet actually posing the lowest risk of bacteria transfer onto dropped food."

So is it safe to eat food off of the floor? Technically, if you're quick enough, it is. But remember that there's always a risk with dropped food, so don't expect it to always be safe. After all, it depends on what you drop and where you drop it. That said, this study shows that dirty floor candy may not be as "dirty" as you once thought.