How Gross Are Your Flip-Flops?

Photo: Danny Kim/New York Magazine

Flip-flops are a summer survival tool. On the steamiest days, relief is measured in seconds of breeze between your toes. But should you then go home, wet some medical gauze, and rub vigorously between those same toes, something less savory can be measured: “They’re full of bugs,” biochemist Don Satchell, Ph.D., of Situ Biosciences, tells me, after I mail him samples of what occupied my feet. “It’s totally disgusting.”

How disgusting? Every inch or so of my skin contained a million microorganisms, roughly the equivalent of raw hamburger meat. Satchell says some of those were likely big, bad buggies such as Candida (a leading cause of hospitalization from fungus!) and Propionibacterium (a leading cause of your feet smelling like the Gowanus!). But they were also covered in mucuslike fungus, which can lead to athlete’s foot. So, burger with mushrooms.

I’d scrubbed my feet in the morning, but that was pointless. Tests showed my years-old flip-flops to already be a harbor of filth, like a wearable Murray Hill bar. “No matter how clean your feet are, as soon as you put them in your shoe, they’re full of microorganisms,” says Satchell. Though my sandals’ undersides were the dirtiest, the arches of my feet carried way more bacteria. The reason: Bacteria needs moisture to thrive, and on a sweaty day, my feet double as Poland Springs.

And yet, none of this should discourage flip-flopping. Soap and water removes 99.9 percent of the bugs, and the survivors are almost certainly not harmful, says Satchell. So wash up. Then relax. Your feet will be just as gross tomorrow.

How Gross Are Your Flip-Flops?