LifeStraw’s membrane microfilters are made of hollow fiber membrane technology – a similar technology used in kidney dialysis. These membranes are made of small straws that contain microscopic pores of 0.2 microns in diameter. Dirty water enters one side of the straws and clean water passes through the pores while bacteria, parasites, microplastics, dirt, silt, sand and cloudiness are blocked and unable to pass through because they are too large. The result is safe drinking water flows into a clean chamber for drinking while contaminants are blocked. LifeStraw’s membrane microfilters are capable of removing 99.999999% (log 8) of bacteria (including E. coli), 99.999% (log 5) of parasites (Giardia, Cryptosporidium, etc.), and 99.999% (log 5) of microplastics.