You know the stench: the one your water bottle gets after sitting for far too long at your desk or in your car. But you may not realise that it smells that way because bottles are magnets for bacteria.
"The types of bacteria you'll find on a water bottle come from your hands or your mouth. There's a wide variety that can stick and grow, and a lot like to grow in places that are moist," Christine McDonald, Ph.D., a microbiologist at the Cleveland Clinic, told POPSUGAR. These bacteria can range from E. coli to staphylococcus aureus, all of which can make you really sick, often with gastrointestinal symptoms.
For that reason, it's really important that you clean your water bottle regularly, ideally after every use. Since that can be a hassle, you might wonder if self-cleaning bottles are all they're cracked up to be. You've likely seen Instagram ads for what claims to be the first ever self-cleaning bottle that "neutralises up to 99.9999% of harmful, odour-causing bacteria using UV-C light."
So, how does it work? "UV light is used in hospitals to disinfect surfaces," Dr. McDonald explained. "It disinfects by using a certain wavelength of concentrated light that fragments the DNA of bacteria and kills them. It can be very effective."
However, since the UV light source is in a bottle's cap, Dr. McDonald is sceptical that it can clean the bottom of the bottle as effectively as the top, especially if there's still water inside. "Another part to consider is you'll still need to clean the top where you're going to be drinking from, since the UV light is not going to be hitting where your mouth touches on the outside," she said.
So, whether or not a self-cleaning bottle is worth the splurge is entirely up to you. If you prefer to spend a little less, Dr. McDonald recommends a copper bottle. "Historically, the best water containers are copper, because copper itself is antimicrobial," she said.
Whatever you choose, be sure to clean it effectively. "If a water bottle is dishwasher safe, that's the easiest and most effective way to clean it, since water gets so hot in dishwasher," Dr. McDonald said. "Or, soak your water bottle in 10 percent bleach for 10 to 15 minutes."