If we had a nickel for every single time someone asked us what NSF 42, 44, 53, 55, 58, 62 and 177 meant… we’d have a huge pile of nickels and STILL not have enough money for that diamond-plated, gold-encrusted, platinum embossed drinking fountain w/ the GIANT water purification FACTORY attached to it from the other side of the wall.
NSF/ANSI Standard 42: Drinking water filtration systems that are certified to this standard remove chlorine and sediment/particles from water for the purpose of improving its look, smell and taste. The design of these filter do NOT lend themselves to the removal or reduction of health-related contaminants.
NSF/ANSI Standard 44: Water treatment systems certified to this standard typically function as cation exchange water softeners designed to reduce or eliminate water hardness (i.e. calcium and/or magnesium). Water filters designed to remove barium and radium may also certify to this standard.
NSF/ANSI Standard 53: Water purifiers certifying to this standard have designs that remove health-related contaminants such as waterborne organisms and industrial chemicals. Cryptosporidium, giardia, volatile organic chemicals (VOCs), MTBE (methyl tertiary-butyl ether) and trihalomethane compounds (THMs) fit into one of those categories or the other.
NSF/ANSI Standard 55: Devices rated to this standard function as point of use (POU) or point of entry (POE) ultraviolet microbiological water treatment systems. These water treatment systems feature designs which disinfect microorganisms (such as bacteria and viruses) potentially present in water.
NSF/ANSI Standard 58: Typically one will find reverse osmosis water systems (RO) certified to this standard. Devices in this category will normally have the ability to fully remove organic contaminants, but may only partially remove inorganic compounds and heavy metals.
NSF/ANSI Standard 62: Certified to this standard one will typically find water distillers. The process of distillation removes a wider range of drinking water contaminants than all other methods of drinking water purification. Arsenic, mercury and bacteria all get eliminated through the use of water distillation systems.
NSF/ANSI Standard 177: Water filtration units certified to this standard function as shower head filters designed to remove chlorine from water.