SANITATION, ARTHROPOD AVOIDANCE, AND WATER DISINFECTION - Medicine for Mountaineering and Other Wilderness Activities - page 74

Ifliquidbleachisusedforwaterdisinfection,thestandardprocedureistoaddtwodrops
to a liter of water with a temperature above 60°F (16°C) and allow it to stand for thirty
minutes. If the water is colder, it should be allowed to stand for forty-five minutes. Liquid
bleach is a much slower disinfectant than iodine preparations or other chlorine prepara-
tions.
MSR MIOX® Purifier (Hypochlorous Acid)
In fall 2003 MIOX® Corporation ( www.MIOX.com ) , in association with Mountain
Safety Research® (MSR), released a new chlorine-based water disinfection system for
individuals. Various much larger units that employ the same electrolysis procedure have
been in operation since MIOX® was formed in 1994. The U.S. Forest Service uses these
devices in several parks, and the units have proven quite valuable in developing countries.
(MIOX® was one of nine companies to receive the presidential E award for excellence in
exporting in 2002.) The Purifier was a Grand Award winner in the General Innovation cat-
egory for Popular Science's “Best of What's New” issue that year.
The system operates by sending an electrical current through a saline solution (brine),
which produces a mixture of oxidants, most importantly hypochlorous acid (HOCl), a very
effective chlorine-based disinfectant compound. In appropriate concentrations the solution
from the small, individual unit effectively eliminates bacteria and viruses from water in
thirty minutes. Parasites take longer. Cryptosporidia —against which hypochlorous acid is
eventually effective, unlike chlorine or iodine—require four hours.
The device contains a small chamber on top into which a salt pellet—or rock salt or
common table salt—is placed. About a quarter teaspoon of water is placed in a second
chamberunderneaththefirst,andtheunitisshakentomixthesaltandwaterandproducea
saline solution. A button is pushed to send an electric current—produced by two three-volt
lithium camera batteries—through the solution. Pressing the button once provides enough
oxidants to disinfect 0.5 liter of water. Pressing it twice yields enough for a liter, pressing
three times provides enough for two liters, and pressing four times yields enough for four
liters. One salt pellet lasts for approximately fifty liters of water, and one set of batteries
can disinfect about two hundred liters.
A green light indicates when the oxidant mixture has been generated, which takes five
seconds to two minutes. Combinations of red and green constant and blinking lights indic-
ate whether the solution is too strong, too weak, too salty, or the batteries are running low.
A chart aids in interpreting the signals. After the solution has been stirred into the water to
be disinfected, test strips are provided to determine whether the water has been adequately
treated.
The solution is reported to add no taste or odor to the water. A number of online public-
ationsproclaimthatiteliminatespumpingwaterthroughafiltertoremove Cryptosporidia ,