The LifeStraw Max Water Filter Can Save You From Contaminated Water

Updated March 21, 2023

The Max is currently out of stock at retail. LifeStraw told us in an email that their entire inventory of Max units was sent to Turkey and Syria to aid in earthquake recovery. They expect to have Max units back in stock the first week of May. For now, you can sign up for a notification when they return.

Tim Heffernan

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Floods, hurricanes, heavy rainstorms, and wildfires can contaminate local water, rendering it unsafe to drink without your boiling it or chemically treating it first. Even absent a disaster, thousands of boil-water notices are issued every year in the US by city and state environmental agencies or water utilities.

This got us wondering whether there's a better solution to the ongoing problem of contaminated domestic water. A filtration device that could deliver clean, disease-free water quickly, without needing electrical power, would be great. One that could do it in sufficient volume to provide a family or even a whole neighborhood with enough water to drink, cook with, and wash with until the crisis passed would be even better.

We found one: the LifeStraw Max.

Proven in the field and in independent lab tests, the Max removes virtually all pathogens and many contaminants, surpassing the performance of most home water filters.

The LifeStraw Max removes virtually all viruses, bacteria, and other pathogens from contaminated water, in addition to reducing sediment and many industrial and agricultural chemicals and dissolved metals. Its abilities surpass those of the water filters many people may have at home already. No bigger than a beach-size cooler (20 by 16 by 13 inches), the LifeStraw Max is easy to store when not in use, and it weighs only 16 pounds, so it's also easy to bring out when needed. The device uses no electrical power but does need to be hooked to a standard garden hose in order to work; thankfully, it's rare for municipal water utilities to shut down even in a natural disaster that causes a boil-water situation. If you experience frequent boil-water orders in your area, the LifeStraw Max is a viable long-term option, and it's far more efficient than boiling—it can purify up to 40 gallons per hour, and its ultrafilters can cleanse 26,500 gallons before you need to replace them. If a group of neighbors shares the purchase cost, it's even more practical, and it can provide clean water to multiple households for weeks.

Our research was inspired in part by Jackson, Mississippi's summer 2022 drinking-water crisis, which subjected more than 150,000 people to an onerous boil-water notice. Flooding and neglected infrastructure resulted in the near-total failure of the city's municipal water supply. Many residents had no water service at all because critical pump equipment and pipes had failed, while those who did have service drew from reservoirs that had possibly become contaminated with disease-causing bacteria. Just months later, in December 2022, a cold snap caused multiple mains to burst, and the entire city was again placed on a boil-water notice. Jackson may be the most visible recent example of the vulnerability of US drinking-water supplies, but it's not alone—and it's not the last of its kind.

I’ve been testing water filters for Wirecutter since 2016. I’ve spoken at length with filter-certification organizations to understand how they conduct their testing, and I’ve spoken with representatives of multiple water-filter manufacturers. For this guide I spoke with Jean-Luc Madier, director of engineering at LifeStraw, and Tara Lundy, LifeStraw's chief brand officer. I also went hands-on with a LifeStraw Max to see how it works and how it might fit into a typical American household's routines.

The LifeStraw Max, introduced in early 2022, was designed as an easily deployed water-filtration system for disaster relief and humanitarian crises in developing nations. "The Max was the answer of ‘the ultimate,’" said Tara Lundy, LifeStraw's chief brand officer. Working on disaster response with organizations such as the World Health Organization, Doctors Without Borders, and UNICEF, the LifeStraw team set out to find a high-volume filtration option for internally displaced people in refugee camps. During the system's development, which focused on removing pathogens, "we looked at it and said, ‘This has applications in the US, too," Lundy noted. (The domestic version has an additional filter that addresses agricultural runoff and dissolved metals; disease is the primary concern in humanitarian efforts.)

Physically, the LifeStraw Max is small (20 by 16 by 13 inches). It's also lightweight at 16 pounds, and its carry handles make it easy to move around. Using a standard garden-hose fitting to connect to an existing water supply, it takes advantage of the pipe pressure to force the water through so-called ultrafilters, which are capable of removing particles as small as individual viruses. The pipe pressure also lets the LifeStraw Max deliver lots of clean water quickly, up to 40 gallons per hour (a gallon every 90 seconds). For comparison, the gravity-fed pitcher-type filters we’ve tested typically take about 10 minutes to filter just half a gallon. (They are also not certified for microbiological filtration.)

The heart of the LifeStraw Max system is its pair of hollow-fiber membrane ultrafilters. "It's very easy to understand," said Jean-Luc Madier, LifeStraw's director of engineering, who oversees its research and development and testing programs. "You have a kind of straw with tiny pores, and the pores are smaller than bacteria and viruses. It's a physical barrier—even if you use it for a very long time, you will never have a bypass."

In the LifeStraw Max's membrane ultrafilters, the pores allow water through but block the passage of anything larger than 0.02 micron (20 nanometers) in diameter. As a result, they reduce virus levels in sewage-contaminated water by 99.999% and bacteria by 99.999999%, rendering the water safe to drink. An additional prefilter inside the LifeStraw Max captures coarse sediment, extending the membrane filters’ life, and a final carbon-block plus ion-exchange filter captures pesticides, petrochemicals, and heavy metals, which may enter water supplies as runoff during major storms. The membrane filters are rated to last for up to 26,500 gallons, and if they become clogged before then, you can back-flush them to clean them out and extend their use.

Like the LifeStraw dispenser we recommend, the LifeStraw Max system has been tested by accredited labs to multiple international standards, including those of ANSI/NSF and the World Health Organization. On top of that, the WHO has tested other LifeStraw products that use the same ultrafilter technology (specifically, the LifeStraw Family 1.0, Family 2.0, and Community) and found them to provide "comprehensive protection," its highest rating (PDF), against bacteria, viruses, and protozoa. Madier, whom we spoke with at length and in detail, has spent more than a decade working on water filtration for disaster and humanitarian relief. And the LifeStraw Max, in its first year of production, has been deployed by LifeStraw itself and partner relief organizations in India, Pakistan, Myanmar, Haiti, the Philippines, Puerto Rico, and Kentucky. (We later spoke with Ernso Sylvain, the Haiti country director for Unlocking Communities. Sylvain also runs an English-language school in the city of Hinche for 150 to 200 children, and LifeStraw provided him with a Max to help prevent the spread of cholera and other waterborne diseases. "It's been such a great thing," he said. ""The day we installed it, the students were so very excited. Before they had to wait for the water to be filtered through a clay system. From the Max, they can get water easily and faster.") Taken together, all of those factors make us confident in the LifeStraw Max as an option for household disaster-preparedness.

To a great degree, the answer to that question comes down to how worried you are about crises such as boil-water orders. If they are a regular occurrence where you live, a LifeStraw Max would ensure that you’d always have a plentiful supply of clean water and would let you avoid the inefficient, unpleasant alternatives of boiling your water or treating it with chemical disinfectants. Compared with prefilled storage containers or crates of bottled water—another disaster-preparedness approach we recommend—the LifeStraw Max takes up far less room, and unlike stored water, it does not need to be regularly refreshed or maintained. Between uses, you just let the filters thoroughly air-dry and then put the unit into storage till the next time you need it.

One important caveat: We’re assuming that your municipal water system will still be functioning even during boil-water orders following a disaster. That's almost always the case—Jackson's double whammy of contaminated supply and disrupted delivery appears to be unique and was the culmination of years of systemwide neglect—but it's something to weigh in your decision-making. Though the LifeStraw Max can also work with a hand pump or even get water through gravity (via an elevated reservoir or water tank), those methods aren't feasible for most households—practically speaking, you need to be able to run it off your plumbing.

We also think it's reasonable for a group of neighbors or a community organization to purchase and use a LifeStraw Max collectively, to help defray its cost. Thanks to the system's 26,500-gallon filter lifespan and rapid filtering process, a single LifeStraw Max could easily provide water to multiple households for several weeks, as long as someone is willing to provide the supply hookup and make it convenient for people to stop by and fill their containers. (When we mentioned this idea to Lundy, who lives in the San Francisco Bay Area, she said, "I’m in the neighborhood-disaster group because I’m ‘the LifeStraw Lady,’ right? And my husband is an ER doctor. It's like we’re the earthquake family. And we have a Max here and have already said to the neighborhood that if something happens, people can just come and fill up.")

If you are never in a situation where you’d get a boil-water notice where you live, the LifeStraw Max would not be worth the cost—but at the risk of sounding alarmist, it is difficult to predict that an area will never be under a boil-water advisory. For everyday water filtration with functioning municipal water, the LifeStraw Max is not as practical as using a regular pitcher, faucet-mount, or under-sink filter.

We haven't found a product comparable to the LifeStraw Max. The types of pitcher filters we cover in our guide, as well as the faucet-mounted and under-sink water filters we’ve tested, are not designed to remove everything that officials may be concerned about when they issue a boil-water notice. In particular, such devices are not certified to remove waterborne microbes like bacteria and viruses. Filters designed for camping, like the Sawyer Mini we recommend in our guide to bug-out bag gear, are effective against bacteria (but not usually viruses) and are so inexpensive that it would be easy to keep a few on hand. But unlike the LifeStraw Max, camping filters are not practical for producing the large amounts of drinking, washing, and cooking water that you would need in an extended boil-water situation.

This article was edited by Harry Sawyers.

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