ÖKO combines water filtration technology originally designed for use in NASA ISS (International Space Station) with a bottle design made of FDA compliant materials. The combination yields a unique filtration bottle which is lightweight, versatile and can deliver the highest quality water from innumerable water sources in over 140 countries. ÖKO Bottles : Made from a special thin-walled plastic similar to food storage containers, our bottles do not leach chemicals in warm climates, or emit odor. They have passed stringent SGS testing for FDA food contact safety. They are BPA and phthalate free. The bottle cap is made of Tritan, a clear hard plastic renowned for its durability and clarity. It also allows the user to see water filtration in action. ÖKO Filters : Originally developed for NASA and used in the ISS (International Space Station), it is simply the state of-the-art in water filtration technology. We convert this super media for for use in our bottles. The material clears water while using a electro-adsorption process to retain negative particles in water. Performance : A filtration capacity of 100 gallons, the ÖKO filter lab tests show removal of 99.999% of giardia lamblia & 99.997% on cryptosporidium, two of the most common contaminants found in open water sources worldwide. Water conditions vary worldwide. Using ÖKO Bottles : Whether planning an adventure trip to far away destinations, hiking, biking or camping or if you are concerned about plastic waste and the environment, ÖKO bottles serve your needs. A single bottles saves as much as 98% of the plastic waste. Originally developed for NASA & used in the ISS (International Space Station), we convert the material into cartridges for our bottles. Simply put, it is the state-of-the-art in water filtration technology. A 2 micron pore size, when the filter is exposed to water, it is positively charged to draw and trap harmful agents much smaller than its pore size. Electro-adsorptive charge fields all but close the pores to any intruding agents while allowing water through. Our EPA and NSF approved lab tests reflect removal of 99.994% of e-coli, 99.9999% of cryptosporidium and giardia lamblia.