Is It Safe To Eat Food From The Floor, According To The 5-Second Rule?

Dropping food on the floor is something that all of us do on a regular basis. If you have children, this is probably something that happens several times a day. When food falls to the floor, someone will almost certainly invoke the "5-second rule," picking it up and eating or serving it anyway.

This so-called "rule" is based on the belief that it takes more than five seconds for potentially harmful bacteria on the floor to attach to and contaminate your food. Bacteria that cause any type of foodborne illness could be among those contaminants. Is the 5-second rule based on scientific evidence?

"I believe in the 5-second rule," says Sana R. Zuberi, M.D., a Henry Ford Health family medicine physician. "I believe it is worthwhile to stop throwing food away."

Dr. Zuberi does, however, acknowledge that some scenarios necessitate greater caution than others. "The less time food spends on the floor, the lower the chances of contamination," she says. "However, the rate of transmission is determined by a number of factors, so time alone is not a guarantee."

The Kind Of Food You Throw Away

There is a distinction between dropping a dry cracker on the ground and dropping a juicy cantaloupe slice. "Moisture has a huge impact on how quickly food can pick up bacteria," Dr. Zuberi says. "Something moist is more likely to pick up contamination than something dry."

A study published in the journal Applied and Environmental Microbiology in 2016 compared contamination times and concentrations for various food types. They examined watermelon, bread, buttered bread, and gummy candy. Watermelon slices, unsurprisingly, picked up the most bacteria the fastest.

Where Do You Leave The Food?

When it comes to contamination, the type of surface the food comes into contact with may also play a role. According to the same study, carpet transferred less bacteria onto dropped food than hard surfaces such as tile.

The type of flooring is a concern, but so is the location. "I would avoid eating food off the floor in places with higher levels of contamination, such as a school, daycare centre, public restroom, or hospital," Dr. Zuberi advises. "Your own home is probably the safest place to be, especially if no one wears shoes inside the house, which can bring bacteria in."

You can also circumvent the 5-second rule by washing food that has fallen on the floor before eating it. Thoroughly rinsing it can help remove any bacteria that have become attached to the surface. (Of course, this option works best with foods like fruits and vegetables and not so well with cookies or bread.)

It Is Important to Time

While the 5-second time limit may appear to be arbitrary, it appears to have some validity.

According to the 2016 study, spending more time on the floor resulted in higher bacteria transfer rates. "Bacteria particles take time to travel and accumulate at a high enough concentration to make you sick," Dr. Zuberi explains. "You're less likely to reach that level of contamination in less than five seconds."

Having said that, the study did discover that certain foods (again, the wetter, more absorbent ones) absorbed some bacteria as soon as they hit the floor.

What's the bottom line? Most of the time, the 5-second rule is probably safe to follow. But, in the end, the safest approach may be to say, "When in doubt, throw it out."