When UV light strikes an organism it causes disruption to the DNA within the cells. In short, it destroys the ability of organisms to grow. UV systems are used in the Detroit Water System and others across the nation and according to the University of Hawaii, UV light actually kills more organisms than the chlorine used in municipal water systems.
For backpackers, the firm Hydro-Photon Inc. has miniaturized the process in the form of the SteriPEN series of UV Light purification systems. These light weight hand held units will kill viruses, bacteria and protozoa in 500 ml (about 16–ounces) of water in 48–seconds and in 90—seconds in 1–liter of water.
All SteriPEN models have been certified by the Water Quality Association as meeting and exceeding all standards set under the U.S. EPA Microbiological Water Purification Standard. If this isn't enough, the units have been used worldwide from Mount Everest to the Everglades and in locations most of us have never heard of.
For those traveling to areas where tapeworms are a hazard, such on Isle Royale National Park in Lake Superior, it must be said that the SteriPEN is not listed as being effective against tapeworm cysts. The only treatment proven effective against tapeworm cysts is either boiling or using a water filter with a pore size of .4 microns or less.
I was given the chance to test the SteriPEN Opti with Solar Charging Case which offers a safe way to store the unit and of course, charge the batteries while on the trail.
The SteriPEN Opti measures 6–inches long, 1.5–inches wide and 1–inch thick and weights 4.5–ounces with batteries and a neoprene storage case.? The solar charger and case along with extra battery weighs 7.6–ounces. So for a total of just over 12–ounces you can carry the entire system.
It is power by either two CR123 disposable batteries or two RCR123 rechargeable batteries and will treat 100–liters of water with the disposable batteries and 40–50 liters with rechargeable batteries.
In addition to being used for purifying water, a white LED, part of the water sensing system, can be activated separately as a flashlight, a rather nice option. Push and hold the activation button and the light turns on for 3–minutes.
Using the system is simplicity itself.
When I tested the unit, I found the instructions printed on it to be invaluable. When you're tired and thirsty it is easy to forget how many times to push the button.