We'd be lying if we said that we've never ever scrambled to pick up a piece of toast that has landed (butter side up) on the ground and put it back onto our plate for eating. But we might think twice about applying the widely-accepted '5-second rule' after finding out that an expert has confirmed what we always knew deep down: that it's a load of rubbish. According to Cosmopolitan, a food science professor at Clemson University, Dr. Paul Dawson, decided to put the rule to the test. He contaminated a number of surfaces (including kitchen tiles, wooden floor and carpet) with Salmonella. He then placed food on it for 5, 30 or 60 seconds before measuring the amount of bacteria that had been transferred. He repeated this test after 2, 4, 8 and 24 hours before collecting the results which showed that the amount of bacteria transferred to the food was not determined by how long it was in contact with the contaminated surface. via GIPHY The thing that mattered was how much bacteria was on the surface and the type of surface - it seems if you're going to drop your food anywhere, do it on the carpet as less than 1 per cent of Salmonella was transferred (compared to 48-70 per cent on wooden floor and kitchen tiles). So there you have it, the 5-second rule is a myth (unless you drop something on a freshly-cleaned carpet) and you probably shouldn't eat something that has fallen on the floor in case it makes you ill. Then again, that is common sense.