Wash well and don't forget the lid: how to clean your reusable water bottle

"reusable water bottles are on the rise. But on social media, people seem confused about how to clean them, and post horrifying pictures of mold growing inside. Water sourced from a municipal water supply is likely very clean, explains Kelly Reynolds at the University of Arizona, who studies water quality and disease transmission. But bacteria and viruses can make their way into a water bottle via our hands and saliva. The water bottle itself is just the perfect environment for bacteria to grow, says Reynolds."

"How to clean your reusable water bottle Wash your hands and wipe down your phone: Before you even get to the water bottle, you should wash your hands. The source of the water bottle's contamination is probably your hands, says Reynolds. But frequent hand washing could also be moot if you don't also wipe down your phone at least weekly, using a cloth slightly dampened with soap and water."

Municipal tap water is typically very clean, but hands and saliva commonly introduce bacteria and viruses into reusable water bottles, creating an ideal incubator for microbial growth. Many people routinely refill bottles without washing or rinsing them, increasing contamination risk. Effective prevention relies on hygiene: wash hands before handling bottles and clean phones regularly. Rinsing with water alone cannot remove biofilm. Proper cleaning options include diluted bleach soaks with thorough rinsing, dish soap with scrubbing using a bottle brush, or vinegar; use gloves when handling bleach and never mix bleach with other cleaners.

Read at www.theguardian.com