— The most dangerous part of playing beer pong might not be drinking too much beer.

A group of Clemson University students tested Ping-Pong balls being used in beer pong games across campus one weekend last fall and discovered teeming bacteria. More research found that dangerous bacteria such as salmonella, listeria, E. coli and staph on the balls end up in the beer when players make successful tosses into glasses.

The research is part of Clemson’s Creative Inquiry program, in which students pose common-sense scientific questions, then plan research to find the answers. Previous classes have debunked the five-second rule that food is safe to eat as long as it is quickly picked up after falling on the floor and shown that double-dipping chips can pose a health hazard.

The goal is to get students to think about the steps needed to scientifically research these types of questions, said food science professor Paul Dawson.

“It’s a learning experience, but I try to make it interesting and fun,” Dawson said.

In most versions of the popular game of beer pong, players toss balls into glasses of beer, then chug the brews. For their work, Dawson’s students first needed Ping-Pong balls to test. They fanned out over campus during homecoming weekend last fall in search of beer pong games.

When they found them, researching students offered players new, clean balls in exchange for those in use. They recorded where the game was played and how long it had been in progress.

The students found the most extra bacteria — 3 million of the tiny organisms — on balls being used in an outdoor beer pong game. A ball being used in a game played on carpet had 200 bacteria on it.

Also in the lab, students put bacteria on Ping-Pong balls and put them in a glass of beer. They found a high level of transfer of the bacteria from the ball to the beer, Dawson said.

While outbreaks of beer pong illnesses aren’t sweeping the nation, playing the game by the usual rules carries unnecessary risk, Dawson said.

The research didn’t surprise Billy Gains, the owner of BPONG, a group that organizes annual national beer pong tournaments.

After tournaments in Las Vegas, Gains said, some participants have complained about coming down with “pong flu.”