This is a brief comparison between NSF 42 vs 53 standards for water treatment system.
Even NSF is not a legal requirement for water filters, it’s good to know about these certified in the case your a purchasing a water filter systems for your home.
NSF 42 vs 53 Comparison Table
|NSF-ANSI 42||NSF-ANSI 53|
|Scope||Point-of-use and point-of-entry systems||Point-of-use and point-of-entry systems|
|Cover||Aesthetic (taste and odor) claims||Health-related claims|
|Reduction Claims||Chlorine, taste and odor, chloramine, particulate, iron, manganese, zinc and total dissolved|
|Over 50 contaminant reduction claims. Some of the most popular include: lead, Cryptosporidium, VOCs and chromium.|
|Testing||Material safety, structural integrity and specific aesthetic-related contaminant reduction|
claims (claims vary by product)
|Material safety, structural integrity and specific health-related contaminant reduction claims|
(claims vary by product)
|POE Test period||16 hours/day or the rated capacity of a filter is achieved||16 hours/day or the rated capacity of a filter is achieved|
|POE Rest period||8 hours/day||8 hours/day|
|Gravity filter Test period||2 - 6 gallons per day||2 - 6 gallons per day|
|Plumbed-in filter systems Test period||50% / 50% On/Off or a 10% / 90% On/Off cycle||50% / 50% On/Off or a 10% / 90% On/Off cycle|
|Testing flow rate||At the manufacturer’s desired rate (Start at the 60 PSI flow rate)||At 60 PSI flow rate|
|Testing conducted||Until it reaches 100% of the manufacturer’s anticipated reduction capacity||Maximum: |
- 120% of the manufacturer’s anticipated reduction capacity if testing with performance indication devices (PID).
- 200% of the manufacturer’s anticipated reduction capacity if testing without PID.
|Exception||Iron and manganese are once conducted to 120% of the system’s reduction capacity||No exception|