July 2021

· 2 min read

What Does Water Filter Certification Mean?

The NSF mark lets you know that a water filter or treatment system has undergone extensive testing to ensure the product’s safety and quality.

Child drinking from faucet - Certification to Water Filter Standards NSF/ANSI 42, 53, 58, 401 | NSF

When you are looking to buy a water filter for your home, you may see a little blue circle containing the letters NSF on products or packaging. This is the NSF certification mark, but what does that mean and who is NSF?

The NSF certification mark means the water filter has been tested for safety to help protect you and your family. Filter testing ensures that:

  • It can remove specific contaminants
  • It won’t leach contaminants into your drinking water
  • It won’t leak
  • It’s been tested for safety

While there is no federal requirement for filters to be certified, the Centers for Disease Control and Prevention and many health departments recommend consumers look for products with certification. That is because the name NSF carries a lot of weight. NSF certification verifies that a water filter will reduce the contaminants the manufacturer claims, such as chlorine, lead, and mercury for example. The NSF mark is well recognized by those who work in public health worldwide.

Who Is NSF?

NSF is an independent, global organization that facilitates the development of standards, and tests and certifies products for the food, water, health sciences and consumer goods industries to minimize adverse health effects and protect the environment. Founded in 1944 as the National Sanitation Foundation, NSF is committed to protecting human health and safety worldwide with operations in 180 countries.

Drinking Water Treatment Standards

The history of drinking water treatment standards goes back to 1970, when President Nixon established the Environmental Protection Agency to address the extent of contaminants existing in our drinking water. As Americans began drinking more water, the demand for home water filters increased. The industry grew quickly, and the market became flooded with low quality, ineffective and sometimes toxic products. NSF facilitated the development of the first American National Standard for filtration in 1973 followed by additional standards throughout the 1980s and today.

How Do I Know If an Item Is NSF Certified?

You can start by checking to see if a product has the NSF mark on the package. Another option is to review the top contaminants people search for using our Contaminant Reduction Claims Guide or search for specific products in the NSF database online to see what your water filter is certified to protect against. Contact us if you have questions.

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