Thursday, September 4, 2008
Someone recently asked if he could use household bleach to disinfect water on the trail. The short answer is "yes." Here's more info: Household bleach typically runs about 5% chlorine. We know that 0.1 ml to 0.2 ml of 5% chlorine bleach added to a liter of water will disinfect it, if you wait about a half hour, killing everything except Cryptosporidium (and it may take an hour or more to kill Giardia). A problem arises in measuring bleach into a water bottle. You can use a measured dropper, one that tells you how much fluid is being dropped, and that's the only way to be sure of your measurement. Others guess at the amount, using a non-measured dropper and estimating that a standard "drop" will be about 0.04 ml. Guessers often add 8 drops of bleach per liter of water in an attempt to be safe rather than sorry. The result is water tasting nastily of bleach, but it won't hurt you. Frankly, even though bleach is cheap, I'd rather use a product that guarantees safe water, such as chlorine dioxide tablets (www.rei.com/product/736898).