How Long to Boil Water So It's Safe to Drink - It's a critical issue when hiking in the wilderness or traveling in some foreign lands. Filters and purifiers can work well, HOWEVER:
The ONLY 100% reliable method for killing waterborne pathogens is boiling.
According to the Wilderness Medical Society...
- water temperatures above 160° F (70° C) kill all pathogens within 30 minutes and
- water temperatures above 185° F (85° C) kill all pathogens within a few minutes.
So by the time water temperature goes from 160° F (70° C) to the boiling point (212° F or 100° C), , even at high altitude.