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 solids (TDS) | 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 |