How LifeStraw Works

LifeStraw is a tube about 9.25 inches (23.5 centimeters) long and about an inch (2.5 centimeters) around [source: Wilhelm]. The outer shell of the unit is made of a durable plastic, with a string attached so users can wear it around their necks. To use it, a person simply sticks the LifeStraw directly into the water source and drinks as he or she would from a straw.

The first iteration of LifeStraw used iodine to kill bacteria, but the 2012 version contains no chemicals. Instead, the product incorporates mechanical filtration. When you suck on your LifeStraw, water is forced through hollow fibers, which contain pores less than 0.2 microns across -- thus, a microfiltration device. Any dirt, bacteria or parasites are trapped in the fibers, while the clean water passes through. When you're done drinking, you simply blow air out the straw to clear the filter. You can down a quart of water in eight minutes using the LifeStraw.

Vestergaard Frandsen says a personal LifeStraw unit should be able to purify about 1,000 liters (264 gallons) of water -- 2.7 liters (0.7 gallons) a day -- meaning that it will last a year before it needs to be replaced. There are no replacement parts; users must get a new unit each year.

LifeStraw Family is a larger unit that can purify enough water for several people at once. This higher-capacity product can handle a family of five for three years, or roughly 18,000 liters (4,755 gallons), according to the company. The product consists of a blue bucket with a prefilter insert, a long plastic tube and a filter cartridge with a tap attached to draw out the water. No electricity or battery power is required. Gravity guides water through a series of filters. The user pours water into the prefilter and bucket at the top of the unit. The water then moves down the tube and runs through the same type of hollow fiber technology that the personal LifeStraw uses, but these pores are actually 0.02 microns across, which makes it an ultrafiltration device. (It also means the family unit can filter out viruses, while the personal one can't.) The user can then pour the newly purified water from the tap. The person can clean the filter by closing the tap and pressing a red squeeze bulb to release the collected residue and can use a rag to wipe the prefilter bucket. LifeStraw Family can filter about 9-12 liters (2.4 to 3.2 gallons) of water per hour [source: Wilhelm].

On the next page, we'll look at what LifeStraw can and can't do.

Both the family and personal models of LifeStraw eliminate sediment, bacteria and parasites from drinking water. The personal filter can stop particles measuring 0.2 microns -- small enough to filter tiny bacteria and parasites. Both models have filters that eliminate 99.9999 percent of the bacteria and 99.9 percent of the parasites present in the water. (As we said, only the family version can filter out viruses.) It's important to note that both versions don't remove heavy chemicals or salt, so don't go sticking your LifeStraw in arsenic-laced water and expect refreshment.

While some people hail LifeStraw and other personal water filters as the answer to the developing world's water woes, others say they're only a temporary fix. Paul Hetherington, spokesperson for the British charity WaterAid, feels the real problem is the distance that some people in remote areas have to travel to a water source, which can be as far as 20 kilometers (12.4 miles) round-trip. He also says LifeStraw is too expensive for the average person in these countries, should they have to procure the units themselves. (They don't currently.) He believes that education on good hygiene and the establishment of a reliable source of clean water in the village is a more viable solution [source: BBC News].

Let's read on to look into some ways LifeStraw is reaching a wide population, as well as its unique -- and occasionally controversial -- distribution method.

The U.N. wants to reduce the number of people without access to sustainable water by half by 2015. While digging new wells and putting in water treatment plants are viable solutions, some experts feel that personal filtration systems are a more successful means of creating clean water. For example, studies have shown that filtration is the most effective way to prevent diarrhea. Treating water at the household level has been proven to be more than twice as effective in preventing diarrhea as treating water at the source [source: UNICEF]. In light of this information, many humanitarian and disaster relief organizations focus on point-of-use water treatment technology. These groups can purchase the personal LifeStraw for a ballpark figure of $6.50 each and the family units at $25. If you're a hiker or camper in the United States and want one for your own use, you'll pay about $20-$25 for personal LifeStraw. Prices, of course, will vary according to when and where you buy the products.

But it's Vestergaard Frandsen's newest way of distributing LifeStraw (through its Carbon for Water program) that has gained quite a bit of attention. The company is actually giving away its product to Kenyans: In September 2011, The New York Times reported that more than a million LifeStraw Family units were already donated in Kenya that year, and the company has made units available to 4.5 million Kenyans so far [sources: Hoffman, Wilhelm].

But the company is definitely benefiting -- economically -- as well, as it participates in a lucrative carbon offset program. By allowing Kenyans to filter their water (as opposed to burning wood to boil it), Vestergaard Frandsen receives carbon credits. Those credits are then sold -- at a profit -- to companies who are looking for a way to offset their own pollution or costs. And thus, the company makes money on its donation [source: Katayama].

This doesn't sit well with everyone. Some point out that the recipients of LifeStraws aren't usually boiling their water, so a carbon offset wouldn't apply [source: Starr]. Then, of course, there's the fact that Vestergaard Frandsen is making a profit when selling the carbon credits, while completing a clever marketing move by putting LifeStraws in many Kenyan homes -- LifeStraws that will someday need to be replaced, presumably.

As filtration goes, LifeStraw is an extremely effective product (and when it's being donated to those in need, a very cost-effective one as well). But UNICEF points out some other personal filtration or water sanitation technologies that also could work in developing nations.

One is good old chlorine. In the right dose, it can kill 99.99 percent of enteric, or intestinal, pathogens (but not Cryptosporidium and Mycobacterium species) [source: UNICEF]. Another cool technology is ceramic water filters, which use an idea similar to LifeStraw. Ceramic naturally has the same small pores -- 0.2 microns -- that can filter out bacteria and protozoa [source: Brown]. They also are sometimes treated with silver to stop microbial growth (which also might make it more effective to kill microbes in general). A 2007 U.N. study of ceramic water filters declared them one of the "best available options for household water filters" [source: Brown]. Then there are solar filters, which -- much like bringing water to a boil through fuel -- heats the water enough to kill dangerous pathogens. The SODIS (solar water disinfection) method is simple as can be: Put your water in PET plastic or glass bottles, and let the sun heat them for six hours (or up to two days, depending on the weather). The process will eliminate viruses, bacteria and parasites [source: SODIS].

After discussing the merits of various point-of-consumption filters -- that is, filters that are used right before drinking -- you might be wondering if water sanitation should be done on a larger scale. Point-of-source interventions (where the water is decontaminated at the source) are also a possibility. But by and large, studies have shown that point-of-consumption is more effective, both from a public health and a cost standpoint [source: UNICEF].

As you can see, bringing clean water to the poorest parts of the globe can be a tricky business -- perhaps with the emphasis on "business." But read on for lots more information about LifeStraw and other options to make water safe for all.