In a viral TikTok video posted on 9 October, TikTok user Jacey (@jaceylmfao) shared with viewers that she washes her bottle “only once in a blue moon”. Alongside the clip, she wrote over the video: “Girl math is never washing your water bottle because if I only put water in it how is it dirty?”
The video - which has since received more than 2.7m views - ended up sparking a heated hygiene debate amongst viewers, with many expressing disgust and pointing out that an unwashed bottle could accumulate “bacterial buildup”.
“This isn’t girl math, this is disgusting,” one viewer commented, with another adding that they were “deeply concerned” for some of the people in the comment section.
Someone explained that Jacey should wash her water bottle more often because “backwash goes down the straw to the bottom and after a while, it grows more slimy”. One viewer cautioned her to wash her cup so that she doesn’t “drink mould”.
Meanwhile, others confessed that they thought Jacey’s habits were the norm, with one person writing: “I thought everyone did this,” to which Jacey replied: “Right.”
She posted a follow-up video two days later, as she addressed her critics accusing her of “drinking mould”.
“It’s ok [because] y’all giving me views and don’t know me,” Jacey said. She clarified in the comment section that she washes her water bottle “once a week or two”.
Dr Timothy Brewer - a professor of epidemiology at University of California, Los Angeles - told The Independent that while there are no formal cleaning guidelines for reusable water bottles, he recommended “cleaning them once a day” or after they’ve been either soiled or contaminated. “If [you’re] drinking a liquid with sugar in it, it would be reasonable to rinse the bottle with clean water after each use,” Dr Brewer added.
Beyond rinsing daily or after use, Bon Appetit suggests that reusable water bottle owners should have one day a week in which they do a deep cleaning. The outlet recommended people use a bottle brush to scrub the harder-to-reach surfaces inside the bottle, as well as leave fizzy cleaning tablets in the bottle for at least 30 minutes. The tablets reportedly gets rid of not only lingering odours but also mildew, which is harder to get rid of in stainless steel water bottles as opposed to clear plastic ones.
Microorganisms have a higher chance of attaching to plastic surfaces than stainless steel and glass surfaces, according to Dr Justine Dees, founder of the Joyful Microbe. She told Southern Living: “Plastic is prone to forming little cracks and grooves and therefore provides more places for microbes to grow.”
Another way to clean a water bottle is with simple pantry items, such as baking soda and hydrogen peroxide. The two ingredients mixed together can not only be used for water bottle cleaning but also for whitening teeth and scrubbing pots and pans.
The Independent has reached out to Jacey for comment.