NSF Certified vs. Tested to NSF Standards

People buy water treatment systems for many reasons. You may be looking for a system to reduce unpleasant taste, odor or discoloration in your water. Or, you may need a system that can reduce harmful contaminants, like lead or parasites.

Whatever your reasons and whatever system you choose, make certain the system you select will do what it claims it will do. How can you be sure the system you purchase will be effective?

Look for the NSF Mark

NSF International tests and certifies that products meet the requirements of strict public health standards. The end result for you: assurance that the system will do what it says it will do. NSF-certified systems do more than just pass a test. For a system to become NSF certified, it must meet not just one, but all five of the requirements shown in this chart.

NSF International puts products through a comprehensive evaluation process, so you’re assured that any NSF-certified product you buy will perform as claimed.

NSF Certified vs. "Tested to NSF Standards"

Know the difference.

Some products are NSF certified. Some only claim to be “tested to NSF standards.” What’s the difference? Ask yourself the questions below:

Question NSF International
Tested to NSF Standards
Are the contaminant reduction claims verified? Yes Unknown
Was the system tested to verify that it adds nothing harmful to the water? Yes Unknown
Has the system been verified to be structurally sound? Yes Unknown
Has the advertising, literature and labeling been verified as accurate? Yes Unknown
Is there testing to verify that the materials and production processes haven’t changed, giving you consistent product quality over time? Yes Unknown