Top Water Filter Certifications & Which One is Right For You


In Brief: Top Water Filter Certifications

The most important water filter certification agencies include NSF (National Sanitation Foundation), WQA (Water Quality Association), UL listings, Energy Star, and ISO standards. These agencies look into different aspects of water filter ranging from its performance to its manufacturing processes.

Water filter systems are abundant in the market in response to the increase in drinking water contamination.

As such it can be very difficult to ascertain which product is genuine and which is not.

In this article, we will talk about water certification standards and their significance in determining a genuine water system.

We will also lay down certain important certification standards you should look for while buying a water filter system for your home.

Why Water Certifications are Important

The increasing need for water filtration has led to a boom in the water filter manufacturing industry.

With the massive number of water filter products available in the market today, it is difficult to ascertain which product is genuine and which is not.

Certification standards help in objectively recognizing the genuineness of a water filter and its effectiveness in meeting the claims that a particular brand or products make.

These standards and certifications are awarded by independent third-party testing agencies and laboratories that are completely free of any biases.

Therefore, when you buy a water filter that comes with necessary certification standards, you can rest assured that they will be effective in fulfilling the claims that they make about the quality of water filtration.

Top Water Filter Certifications for USA

There are several certifications that you can look out for when considering buying a water filter.

We have mentioned some of the most important ones here.

NSF/ANSI Standards

NSF refers to National Sanitation Foundation, which was started in 1944, and later joined by ANSI (American National Standards Institute).

They assist in overseeing water treatment and water distribution products in North America. They consider the safety and integrity of using a water filter for treating your water.

They do a complete and thorough product review including testing and evaluation to ensure that the product meets their standards.

The product review is voluntary. For every product, they assign an independent NSF project manager who acts as a point of contact for the manufacturer.

Their testing and evaluation techniques are very thorough and efficient.

They offer several standards and certifications to assess the quality and efficiency of water treatment. Some of the most important standards include NSF 42, NSF 53, and NSF 58.

They check the product for their efficiency in removing contaminants like chlorine, organic chemicals, asbestos, etc.

Learn more about NSF’s regulatory standards here>

Water Quality Association (WQA)

WQA refers to the Water Quality Association and is made up of more than 25,000 members around the world.

It is a Gold Seal certification program is an independent standard of approval ensuring that the device or product is its scientific testing procedures and is safe for usage.

WQA gold seal certifies a product for their durable construction, build, and usage conditions. this certification covers everything from chemicals to plumbing components to filtration systems and water softeners.

It ensures that the manufacturer meets the guidelines for the manufacturing processes and the material used.

Apart from that, it also provides sustainability certifications in the drinking water treatment industry.

Products with the WQA sustainability certifications are ethically manufactured according to environmental standards and adhere to the best practices in corporate social responsibility.

Learn about WQA certification standards>

Underwriters Laboratories

UL refers to Underwriters Laboratories. As an organization, it has been testing and approving products for consumer safety since 1894.

It was founded in Chicago and has since expanded worldwide.

It tests water filters for usage safety against the national standard for safety.

A peculiar thing about UL testing is that it does not stop at the initial evaluation of the product but ensures the ongoing safety of the product from time to time through surprise visits.

If the product no longer satisfies the safety parameters of UL, its listing and certification are taken away.

Follow this link to learn more about UL listings>

ISO standards

ISO refers to the International Standards Organization. Its certification has to do with environmental impact and the performance of the product being certified.

Two ISO certifications should be specifically noted when buying any water filtration system. They are ISO 9001 and ISO 14001.

ISO 9001 ensures that the manufacturer has met the parameters of management commitment.

ISO 14001 deals with environmental performance and ensures that the product has been manufactured holistically and has controlled the impact of its activities on the environment. It also issues a range of standards concerning water quality.

Learn about ISO’s certification standards from this link>

Energy Star

This one is not related to water filter and water quality but an important one.

Energy Star was started by the Environmental Protection Agency in 1992 as a program to cut down on computers that were draining energy.

It later expanded its scope to all household appliances including water filters.

Products with energy star meet the parameters of energy efficiency established for energy-saving and variable performance. This certification ensures that your product is as efficient and environmentally protective as possible.

Follow this link to learn more about their energy standards>

NSF 42 VS NSF 53

Both NSF 42 and NSF 53 are certifications awarded by the National Sanitation Foundation regarding the standard parameters of a water filter and targets their ability to fight off certain specific contaminants.

These are two of the most important standards to look out for while buying a water filter system.

NSF 53 certification is provided to filters that meet the minimum safety requirements to reduce specific harmful water contaminants.

These contaminants include lead, cryptosporidium, giardia, volatile organic compounds, and methyl tertiary butyl ether (MTBE).

This certification typically applies to a water filter that uses carbon absorption. Apart from contaminant reduction claims, NSF 53 also includes structural integrity and material safety.

NSF 42, on the other hand, evaluates the capacity of a water filter to remove chlorine and other tastes and odors from water.

This does not include the harmful by-products of chlorine.

Water filters with NSF 42 certifications can have a varying degree of effectiveness in the removal of chlorine.

This standard applies to both points of entry and point of use devices.

Which Water Filter Certification is Relevant for You?

To understand which certification to look for while buying a water filter, let us first take a look at the common contaminants present in different water sources.

Water typeCommonly found contaminants
Tap WaterLead, chlorine, chloramine, mercury,
volatile organic compounds (VOCs),
herbicides, copper, and bacteria
Well water Microbiological contaminants, heavy metals,
fluoride, nitrates

Now you know about the common contaminants present in water.

Let us take a look at what certifications you should look for in a water filter to ensure its effectiveness in dealing with these contaminants.

Contaminant type Certification to look for
Chlorine ANSI/NSF 42
Iron, manganese, zinc reductionANSI/NSF 42
Heavy metals (Arsenic, copper, lead)ANSI/NSF 53
Inorganics (Fluoride and nitrate) and organic volatile compoundsANSI/NSF 53
Microbiological contaminants ANSI/NSF 244
Pesticides and herbicidesANSI/NSF 401
Calcium and magnesium ANSI/NSF 44

However, if you have already decided on the type of filter you are going to buy, you should look for NSF certifications that ensure quality build and structural integrity of the water filter.

Take a look at the following table to see which certification to look for in a particular type of water filter.

Filter type Certification to look for
RO system ANSI/NSF 58
Carbon filtersANSI/NSF 53
Microbiological water purifier NSF P231

We hope that these tables help you in buying a good certified water filter to help you gain access to filtered and healthy water.


Certifications are the most objective way of determining the efficiency and efficacy of a filtration system.

We hope that this article helps you in understanding the significance of certification standards when it comes to buying a water filter system for your house.

About Jennifer Moore

I'm Jennifer and I am a hardcore car racing lover. I have been writing on automotive topics for more than 8 years now, specializing in performance enhancement. My passion is to help people find the best of what they are looking for, be it an engine or a set of tires. If you want to know something about cars and how they work, just ask me!