The over/under debate has been settled. Thanks to the University of Colorado, couples and roommates everywhere can stop arguing about the correct way to hang toilet paper. Toilet paper should be hung over with the loose end draped over the top of the roll. 

Why? Because as Geoffery James breaks it down in his recent article, ‘The Correct Way to Hang Toilet Paper, According to Science’, over is more sanitary. James wrote:

According to science, the correct way to hang toilet paper is “over.” Why? Because “under” vastly increases the possibility that food-poisoning bacteria will spread from the restroom to the rest of the workplace.

And, there’s A LOT of germs in both men’s and women’s restrooms. Particularly in public restrooms. The UC Boulder study revealed 19 different groups of bacteria on the doors, floors, faucets, handles, soap dispensers, and toilets.

The main issue is that bacteria – particularly e. coli – is one of the most common sources of food poising. We’re at our biggest risk of exposure while in the bathroom. In large part, this is because of toilet plumes.

Toilet plumes are what occurs “when the force of flushing sprays microscopic particles of pee, poop, and whatever else is in the bowl into the air.”

However, one of the other most common ways we can be exposed to bacteria is the toilet paper roll. As James explained, “The moment when a restroom user’s hands are most likely to carry bacteria is when they reach for toilet paper.”

By hanging the roll so the paper hangs over the top, the user only touches the paper they will use. This cuts down on contamination and the spread of bacteria.

It’s also worth noting that you should make washing your hands a priority. Most individuals just splash a little water and soap for a couple seconds. This is practically worthless. You want to scrub with warm water and soap for at least 20 seconds.

Get more practical bathroom safety tips.