Water Bottle Safety

October 1, 2003
Suzanne Driessen
Regional Extension Educator, Food Science
(320) 632-0161
Toll-free: 1-866-401-1111, ext. 161
Email: driessen@umn.edu

Last week I met with a food scientist on the University of Minnesota St. Paul Campus. She emailed me the next day and told me I had forgotten my “water bottle.” She asked if she should do a plate count to see what was growing in it before she threw the bottle away. She told me she might water her plants with the leftover water because they like microbes. This professor made me curious so I asked her, “Is it safe to reuse commercial water bottles?” She referred me to the results of a study she read in Environmental Nutrition (August 2003).

Researchers at the University of Calgary collected 75 water bottles from elementary students. Significant levels of coliform bacteria—bacteria from feces—were found in 9% of bottles tested. Unclean hands were used to open the cap of the water bottle. High levels of bacteria that feed on other organisms (heterotrophic), like salvia and food particles, were also found in 13% of the samples. Salvia and food particles can get into the water bottle and if left sitting on a desk at room temperature for several hours, bacteria can grow to harmful levels.

These commercial water bottles are made with plastic designed and intended for one-time use. The water bottles sold in sporting good stores are made from a more durable plastic. They are a better alternative and are designed to be used over and over. The opening of the bottle is wider making it easier to clean.

If you refill a commercial water bottle or any container for that matter, washing it every day is critical to prevent bacteria from contaminating this healthy beverage. Wash the bottle with hot soapy water, rinse well. Use a bottlebrush to clean in and around the neck of the bottle. Scrub the lids with a brush. Allow the water bottle and cap to air dry completely between uses.

Because of the narrow neck of most commercial water bottles, sanitizing your water bottle in the dishwasher isn’t the best option because water can’t get up into the bottle for a thorough cleaning.

Most people use their hands to open the caps of the water bottle. Another basic but important part of keeping your water bottle germ free is washing your hands well after using the bathroom! Using your teeth to open the cap might be a safer option than your hands. Water bottles can be safely reused if you wash your hands and the bottle well and often.