How often should you wash your water bottle?

How often should you wash your water bottle?

Do you use your reusable water bottle multiple days in a row without washing it? Do you wash it and then refill it before it dries completely?

Both habits can lead to bacterial growth and illness.

A study published in Food Protection Trends looked at the germs in 90 reusable bottles and found that coliform bacteria like E. coli, which can cause stomach illness, was among the most common.

The 2017 study showed that saliva backwash in your water bottle leads to bacteria breeding, especially if you keep your water bottle at room temperature all day or use an opaque bottle, as dark and moist environments are breeding grounds for bacterial growth. The study pointed out that while consumers may realize the importance of cleaning food-contact surfaces, they don’t realize that it’s just as important to thoroughly clean water bottles. Besides E.Coli, other common foodborne organisms associated with unclean water consumption include Salmonella and Campylobacter.

“At a minimum you should pour out water from your reusable water bottles at the end of each day to eliminate some germs,” says Dr. Robert Citronberg, an infectious disease specialist at Advocate Lutheran General Hospital in Park Ridge, Illinois.

“However, to get rid of the bulk of the bacteria and decrease your likelihood of getting a stomach bug, you should scrub the entire bottle, inside and outside, including the lid and straw, and let it air dry completely after you finish each time,” says Dr. Citronberg. “The use of a bottle brush for these popular tall bottles that have the thin necks is key, and I recommend using dish soap or better yet, a bleach-based cleaning product labeled safe for drinkware.”

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  1. Mary Lou Geralts March 14, 2019 at 3:51 pm · Reply

    What is the harm caused?
    What illnesses, rates of illnesses, were caused by the bacteria?

  2. How many days can you use the water bottle prior to cleaning it?

  3. Standing water and saliva can lead to bacteria growth, which for some people can cause a stomach bug — vomiting, diarrhea — or worse for those with compromised immune systems. There is a link to the full study in paragraph three if you would like to read it.

  4. It’s recommended you clean it after each use – once you have finished a bottle full. If you don’t finish the bottle at the end of the day, you should pour out the remains and thoroughly clean the bottle.

  5. Interestingly, no information was sought from study participants regarding illnesses that may be the direct result of E. Coli ingestion.

    One might think that given the large numbers of water bottle users, if surface contamination was such a significant health risk we would have heard about it.

    Thus, the level of surface contamination on a water bottle may have little correlation with the true risk of illness.

About the Author

Kate Eller
Kate Eller

Kate Eller was a regional director of public affairs and marketing operations for Advocate Health Care. She enjoys road trips, dogs, minimalism, yoga, hiking, and “urban hiking.”