How Bad Is It Really to Eat Food That Fell on the Floor?

You're cooking the perfect dinner and then suddenly — splat! — one of your key ingredients hits the floor.

While your more cavalier loved ones might quickly pick up the food and toss it back into the pan or eat it (while faithfully reciting the five-second rule), it's fair to wonder if food that's been on the ground for a few seconds might actually pose a risk. After all, in today's COVID-19 world, we're all thinking a lot more about germs.

But there are clear risks in eating food off the floor, no matter how clean your floors are or how strictly you enforce a no-shoes rule in your kitchen. Here are just a few things to think about when deciding what to do with your fallen food.

Consider this: There are more types of bacteria that live in your home than in your yard.

In fact, the diversity of fungi and bacteria was 50 percent higher in indoor environments than outdoor environments in a September 2015 study in the journal ‌Proceedings of the Royal Society B‌‌.‌ Some of them have negative effects on human health and can wind up on your floors.

"Nobody wants to waste any food, but in reality, there is absolutely the possibility of getting sick from eating food that's fallen on the floor," says Toby Amidor, RD, CDN and author of ‌The Best Rotisserie Chicken Cookbook‌. "Your body does have a defense system, but there is only a certain degree to which it can take care of things."

For instance, if you prepared raw chicken for lunch, your floor may be hosting salmonella — a bacteria that can cause diarrhea, fever and abdominal cramps within eight to 72 hours, per the Mayo Clinic.

Or, if you made tacos with ground beef last night, your kitchen floors could have a harmful strain of Escherichia coli (E. coli) bacteria called E. coli O157:H7, which can cause diarrhea, abdominal cramping and pain, and nausea and vomiting three to four days after exposure, per the Mayo Clinic.

"In less than five seconds, you've already picked up contamination from the floor."

And if you have a pet, they can bring bacteria into your kitchen depending on what they step in outside (or in their own litter box).

For instance, feces from an infected cat can spread ‌Toxoplasma gondii‌, a parasite that causes a disease that can lead to serious health problems in high-risk individuals. Symptoms resemble the flu and include muscle aches or pains that last for months, plus blurred vision and red eyes, per the Centers for Disease Control and Prevention (CDC).

"Pets can actually spread pathogens to humans through the floor," says Randy Worobo, PhD, a professor of food microbiology at Cornell University. "There are so many ways contamination gets on the floors. That's why it's a general rule that if it lands on the floor, it's better to not use that food."

Even walking around your home can spread germs, which is why taking your shoes off when you get inside doesn't guarantee your floors are safe.

"If someone had diarrhea because of a foodborne illness, there could be contamination on the floor in the bathroom," Dr. Worobo says. "You could be tracking that potential pathogen throughout the house."

Unfortunately, if you've been citing the five-second rule as a reason to munch on food after it's fallen to the floor — it isn't true.

"In less than five seconds, you've already picked up contamination from the floor," Dr. Worobo says.

In some cases, the transfer of bacteria to food begins in less than one second, per an October 2016 study in the journal ‌Applied and Environmental Microbiology‌. While the researchers found that longer contact time does result in more bacterial transfer, factors like the type of food and the surface it falls on also play a role.

Out of four different types of food analyzed in the study — watermelon, bread, bread and butter and gummy candies — watermelon picked up the most contamination and gummy candies picked up the least.

"Wet foods are definitely going to pick up more of the contamination on the floor compared to dry foods," Dr. Worobo says. "The moisture actually improves the amount of contamination that's lifted off the floor."

The study also found that carpet has a very low transfer rate compared to tile and stainless steel, and that the transfer rate from wood tends to be more variable.

In terms of whether or not the bacterial load on food can get you sick, it'll vary widely on a case-by-case basis — but it's important to keep in mind that bacteria on your floor may add to other bacteria already present on the food.

"The food is handled at multiple locations — it changes hands and you're prepping it," Amidor says. "It has the chance for contamination at various points, so falling on the floor is just another point for introducing some microbial load."

Even if your floors are spotless, it doesn't mean they're free of germs.

"The word 'clean' means that something is clean of visible dirt, but 'sanitary' means that it contains safe levels of microorganisms," Amidor says. "You'll never have a sterile floor with absolutely no organisms in your kitchen, and some pathogens can actually survive for many months."

Plus, there are many spots on your floor where bacteria can camp out — even if you do clean the floor regularly.

"If you have wood floors in your kitchen, pathogens can be in between the cracks on the surface," Dr. Worobo says. "If you have a grouted tile floor, that grout is not really that easy to clean and there are locations for pathogens to reside in it."

How long a pathogen actually lasts on your floor will depend on a variety of factors, including the type of floors you have and how absorbent they are, plus temperature and humidity.

"It's highly variable — it'll vary from house to house, coast to coast and state to state," Dr. Worobo says. In other words, the risk of eating food off your kitchen floor isn't a "one-size-fits-all" scenario, and you'll never really know just how sanitary your floor is.

Even if you claim to have a stomach of steel, if you get sick with a particular pathogen, it could put high-risk individuals around you in harm's way.

"I've always heard people say, 'Food can drop on the floor and I'll eat it and be fine,'" Amidor says. "But you might have a high-risk individual that you live with, like a child under six or an older adult who is 70 or over. They're more susceptible to illness because they have weaker immune systems, or not fully developed immune systems in the case of the young."

The same goes for if you're living with a person who is pregnant or someone who has a higher-risk immune system due to diseases like cancer or diabetes.

Amidor and Dr. Worobo agree: It's a bad idea to eat food that's fallen on the ground.

"I would never recommend eating it," Amidor says. "When you drop food on the floor, it's a shame, but you should toss it out for safety reasons and just try to be a little more careful when prepping your food."

Even if you've never knowingly gotten sick in the past from eating food off the ground, it doesn't mean that will always be the case.

"I'm not saying you're going to get sick every time, but there certainly is an increased possibility that you can get sick," Amidor says. "Maybe in the past you had a bout of diarrhea a few hours after eating a piece of food off the floor, and didn't realize the connection."

When in doubt, toss it out — and that goes for any food that's on the floor instead of on your plate.