One of the few rules kids (and some adults) actually like to follow is the five second rule. This rule states that any food that falls on the floor is safe to eat, as long as you pick it back up before you can count to five. Not only does this “rule” just seem gross, it can make your children sick or even give them food poisoning.

It may seem silly, but there have been various studies testing different aspects of the “five second rule”. They’ve studied everything from how many germs stay on surfaces to how long it takes them to transfer onto food. Here are a few things they’ve discovered.

The big issue when it comes to the five second rule is whether floors really are actually dirty. While many floors have visible dirt, that doesn’t necessarily mean they have bacteria on them, and dirt won’t likely make you very sick if there’s no bacteria in it. Tests have been done on public floors which have shown them to be fairly clean; however, tests have also been done which show that dirt dropped on the floor can leave enough biological material on the floor to make you sick, and that it stays there for over 24 hours.

When it comes to getting germs on your food, time does matter. If you leave food sitting on your floor for a minute, it’s going to get more dirt and germs on it than if the food is only sitting on it for a few seconds. But that doesn’t mean that food left for only a few seconds is safe. Studies show that hundreds of bacteria can be transferred onto food in just a few seconds of contact. When certain bacteria only require to be ten in number to make you sick, that’s a good reason to just throw the food away.

When it comes to the five second rule, it depends a lot on what the food is, and what the surface is that it falls on. If dry food (like a chip) falls on a dry, smooth surface (like linoleum), the food will probably not pick up many germs. But if you’re dropping a stickier food or if it falls on a carpet, it’s more likely to pick up germs and make you sick.

So, what if you just washed your floor and it’s sparkling clean? While there may be little dirt on your food, there may be the chemicals you used to clean your floor or other surface. Chemicals used to clean dishes are made to be non-toxic and easily wash away to keep you and your family from getting sick. However, chemicals made to clean floors and sanitize counters don’t follow the same standards and can make your family very sick if they’re ingested.

If you’re concerned about your family’s health, it’s best to forget about the five second rule and just throw away any food that falls on the floor. This means you need to teach your kids the dangers of the five second rule, no matter what their friends tell them.