Broken: water filtration systems, product certification and counterfeit filters

This article originally appeared in the March 2022 issue of WQP under the title “Filtration Systems & Product Certification”

Access to clean drinking water is a luxury that Americans often take for granted. Water scarcity is a growing problem, with more than 2 billion people living in countries with insufficient water supplies and 4 billion people experiencing severe water scarcity for at least one month each year. Although the problem of water contamination from droughts and extreme weather events is a much bigger problem that needs to be addressed, filtration systems can serve as a short-term solution to help remove harmful contaminants from water. ‘potable water.

Water filters reduce contaminants in water which, in large amounts, can make it unsafe to drink. Contaminants like lead are often undetectable to the naked eye, but can have serious consequences if consumed at dangerous levels. Filters are designed to reduce specific contaminants, but it is important to know that a filter may not treat all possible pollutants. Finding out which contaminants can pollute your water through your local water quality report is an essential first step in determining which water treatment system is right for your home. For this, NSF International provides a helpful guide to effective filters for common contaminants.


Understanding Water Filtration Systems

Consumers are the primary target of residential filtration units, especially those who are concerned about their water quality, have weakened immune systems, or live on private wells. According to the US Centers for Disease Control and Prevention (CDC), private wells are quite common, with more than 15 million US households relying on them for water. Those who live on private wells often have to use a water softener or remove particles from their water with a pre-filter.

Also, contaminants in the water may be more prevalent in some parts of the country than others. Rural areas, for example, generally fail to meet water safety standards more frequently than urban areas. Even if none of these situations apply, there are still non-health related applications of water filtration systems, as many people purchase filters to improve the taste of their water.

Filtration systems are categorized into two main types: point-of-use (POU) systems and whole-home/point-of-entry (POE) systems. POU systems treat water where you drink or use it, such as your kitchen sink or refrigerator. Examples of POU systems include personal water bottles (pitchers, dispensers, or flow-through filters), faucet-mounted filters, under-sink or plumbing systems, under-sink systems hooked up to some type of faucet separate, plumbed to separate faucet systems and refrigerator filters.

Conversely, POE systems treat water as it enters a residence. They are usually installed near the water meter (municipal) or pressurized storage tank (well water). Whole house treatment systems include UV microbiological systems, water softeners or whole house filters for chlorine, taste, odor and particulates. For these systems, it is important to note that decisions about which filters to install will likely be made or influenced by those involved in the construction process.

The value of certification

To ensure that your filtration system is doing its job effectively, it is important to know if your filtration system is certified by a professional organization or a third-party regulatory body.

NSF tests and certifies water treatment products for material safety, structural integrity, and the product’s ability to remove contaminants. These certifications guarantee that the product works as it claims, which reassures both consumers and manufacturers. According to an independent study conducted on behalf of NSF, 75% of consumers would buy a product with a certification mark rather than one without.

NSF certified products are given certain numbers – i.e. NSF/ANSI 53 – which correspond to the specific standard to which the product has been certified. For example, a carbon filter that achieves NSF/ANSI 53 certification has been tested to reduce a contaminant correlated to a health effect. These NSF standards cover different types of filtration systems used, the contaminants that are reduced, as well as the effectiveness of softeners in reducing water hardness, among several other requirements. These systems are not designed to remove all possible contaminants, so it is essential to ensure that the system you purchase is designed to deal with the contaminants that are polluting your water.

Change your filters

Once your water filtration system is installed, you must familiarize yourself with the life cycle of the product, otherwise the filters can lose their effectiveness. When mechanical filters need to be replaced, the pores of the filter become clogged with debris, making it difficult for water to pass through. It is usually easy to tell when these need to be replaced since the water flow is greatly reduced. Some filters, however, work by contaminants adhering to the surface of the filter media. For these, it is much more difficult to spot when the filter has reached the end of its life cycle.

Most filters need to be replaced regularly and the recommended change cycle varies from product to product. Some filters may only last a few months, while others may remain effective for over a year. The duty cycle can be for a specific number of gallons or an estimate of the number of months a cartridge will last in an average home. Some filters also have indicator lights that let you know when they’re ready to be replaced, while others need to be manually monitored.


Spot counterfeit filters

Finding an NSF certification logo on your filtration products is usually a testament to its effectiveness, but it’s important to stay vigilant to avoid counterfeit filters. Fake filters are increasingly common and difficult to spot. In 2019, US Customs and Border Protection seized more than 5,000 fake refrigerator filters in California that were found in shipment from China. Counterfeit filters are almost indistinguishable from NSF-certified filters, but they have not been inspected by the organization. These filters may not work as they are supposed to and can potentially expose consumers to dangerous contaminants found in unsafe drinking water or, even worse, they can introduce harmful chemicals into already clean water.

Fake filters are usually marked with the logo of a certification body, which makes them particularly difficult to differentiate from genuine ones. To avoid the possibility of purchasing a counterfeit filter, research your products in the NSF database and always purchase through the manufacturer’s website or another legitimate source.


Water filtration systems serve several beneficial purposes and are designed to remove contaminants that can compromise the safety of your drinking water. Certifications ensure that your filters are working properly and successfully reducing the contaminants they are meant to reduce. It is the consumer’s responsibility, however, to remain alert to when filters need to be replaced and to ensure filters are genuine by purchasing only from trusted sources.

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