UV Light Disinfection

A busy schedule, much of it keeping me away from computers the past month, has caused a marked decrease in my postings. Hello to all who have checked back in--and thank you for your patience.

With the increasing use of ultraviolet light devices to disinfect water an increasing number of questions about the devices have hit my screen during my absence. If you follow the manufacturer's directions, you're pretty much assured safe drinking water (see www.steripen.com). But what about the water on the outside of the bottle? It's not safe. Only the water inside the bottle is disinfected, and that does not include the water trapped in the threads of a standard water bottle. If you wipe the threads dry with a clean cloth, however, you will remove most--maybe all--of the pathogens trapped there. In other words, a thorough drying of the threads and it is highly unlikely you'll get a waterborne illness. On the other hand, the safest bet of all is to use a container other than your water bottle to scoop up the water you'll be disinfecting. A cup you'll be washing later will work fine.