This article exists as part of the online archive for HuffPost Australia, which closed in 2021.

You'll Never Unlearn How Many Germs Are On Your Water Bottle

BRB, washing every bottle we own.
Midsection of traveler holding water bottle. Female is wearing casuals. She is sitting on rock.
Neustockimages via Getty Images
Midsection of traveler holding water bottle. Female is wearing casuals. She is sitting on rock.

Well, this is certainly something to sip on.

We love reusable water bottles for being environmentally friendly and their cost effectiveness. But let’s be real: They’re a pain to continuously clean. That may prompt us to skip a few washes and keep using them. And, as it turns out, this could result in ingesting a host of germs along with our H2O.

According to 2016 data, reusable bottles can have as many or more organisms as some of our most germ-infected items (think tooth brush holders, toilet seats and pet toys).

Researchers collected 12 swabs of three different types of water bottles that hadn’t been washed for a week. They analyzed the swabs in a lab and found some of the bottles had approximately 300,000 colony-forming units of bacteria per square centimeter. A used pet toy, on average, has less than 3,000 units per square centimeter, according to the analysis.

Of course, this study wasn’t published in a peer-reviewed journal or subjected to rigorous scientific testing, so it’s hardly definitive. However, it does seem to corroborate the theory that unwashed bottles are a host for germs based on previous research conducted on the subject.

A 2002 study published in the Canadian Journal of Public Health examined more than 70 samples of water from bottles of elementary school students, some of which were reused without being cleaned. They discovered that almost two thirds of the samples had levels of bacteria that exceeded clean drinking water guidelines. The likely source of the contamination? From the kids’ hands.

“Inadequate and improper hand washing after students have used the bathroom facilities could result in fecal coliforms in the classroom area,” the study authors wrote. (”Fecal coliform” is the scientific term for poop-like particles. Yuck.)

Bacteria can also breed in other ways, like through backwash or moisture that forms from a bottle sitting at room temperature. And as with anything bacteria-related, ingesting it has the potential to lead to some physical side effects, like nausea or diarrhea.

So... what do we do?

All that being said, there’s no reason to panic. If you do ingest bacteria (and it’s likely you do in other ways, too) most of these stomach issues don’t come to fruition or typically resolve themselves, according to Kelly Reynolds, an associate professor at the University of Arizona’s Zuckerman College of Public Health.

“In healthy individuals, gastrointestinal infections are generally self-limiting, meaning they go away on their own ― usually within a few days ― without treatment,” she recently told HuffPost. “Some infections can last weeks, however, and lead to more severe health complications.”

It’s an obvious antidote, but cleaning bottles after every use really is the most effective way get rid of pesky germs. But how we wash it is a little more complicated.

If you’re reusing a regular, plastic water bottle (like the ones you pick up in the checkout line), it’s not advisable to just toss it in the dishwasher. The heat from the machine may break down some of the elements on the plastic, which puts you at risk for mixing them with your water when you go to take a swig again. Dishwasher-safe bottles, of course, are fine and the risk of impacting the chemical components of the plastic are minimal.

According to experts, though, the best type of reusable bottles are ones made of materials like stainless steel (which may actually be more germ resistant, Shape.com reported). And if you don’t have a dishwasher, it’s best to wash them using hot water, soap and bottle brush to get into all the nooks and crannies. It’s also just good hygiene to keep your hands clean as it reduces the risk of transmitting germs on any surface.

Now, if you’ll excuse us, we have some major bottle washing to do.