What Does It Take to Get a Water Filter Certified?

Posted by Kenton Jones on Aug 29th 2022

You care about the quality and cleanliness of your drinking water. With a growing number of contaminants and chemicals sneaking into water supplies, it's essential to protect yourself from potential adverse health effects by filtering your water. It can be challenging to determine which water filtration system is best for your needs. Fortunately, choosing a water filtration system with third-party certification guarantees that your water meets multiple safety, effectiveness, and quality standards.

Water filter certification ensures that your filtration system meets independent quality standards so you can be confident in your water quality. Learn about water filter standards and certifications to decide which water filter is best for you.

Why Are Certified Water Filters Important?

Having access to clean, healthy water is vital to your wellness. When you choose to drink and use clean water in your daily activities, you improve your overall health through hydration. Using water filters also reduces water contamination in your home. These contaminants can cause adverse side effects like irritation and illness. For example, the chemicals perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) in drinking water have been linked to harmful effects, including reproductive issues, poor immune function, and some cancers.

Water filters help ensure that the water you use is of high quality. So how do you know which water filters to select for your drinking, bathing, and washing your fruits and vegetables? Water filtration manufacturers have been known to exaggerate their products' capabilities and effectiveness. It can be challenging for consumers to know which information they can trust.

Water filter standards are an objective guide that consumers can use to find high-quality water filtration systems. Third-party testers put out these standards and provide testing and certification for water filtration products. Certification allows for a true apples-to-apples comparison by an independent third party. Ultimately, certification is the key to understanding water filter performance.

An independent organization that certifies water filter performance puts the products through rigorous testing and provides impartial certification. Certification offers a report of information like:

  • A list of the contaminants a system reduces
  • The effectiveness with which the system can reduce each contaminant
  • The system's filtration capacity

How Water Filters Are Tested for Certification

Water filter certification requires that products pass several tests to verify the system's quality. Organizations like NSF and American National Standards Institute (ANSI) develop professional standards for products like water filters to provide testing programs with guidelines for ensuring quality.

There are several types of water filter certifications involving different kinds of tests. It's essential to look for NSF certification, as this third-party organization always performs rigorous testing to ensure every water filtration system complies with the same standards.

Certification organizations usually test for a filter's performance in the following areas.

1. Contaminant Reduction

Reducing contaminants in drinking water is the primary function of water filtration systems. Third-party testing determines whether the filtration system can reduce a wide range of contaminants, including:

  • Chlorine
  • Chloramine
  • Pesticides
  • Trihalomethanes
  • Lead
  • Mercury
  • Pharmaceuticals
  • Bacteria
  • Viruses
  • Cysts
  • Asbestos
  • Microbial contaminants
  • Perfluorooctanoic acid (PFOA)
  • Arsenic
  • And more

2. Filtration Efficiency

Certification organizations test for a filter's efficiency at reducing contaminants. The system's performance is expressed as a percentage and demonstrates how well it reduces different contaminants. A filtration system that has been tested for its efficiency over the life of the filter, not just for a few gallons, has a more reliable filtration efficiency percentage.

3. Filter Structure Integrity

Water filter standards ensure that the system's structure is sound. Different tests evaluate the system's integrity and determine how long it can last. Third-party testers might also audit the facility that manufactures the water filter to determine whether the filtration system was manufactured from approved components and materials. Water filter manufacturers should use materials that won't leach contaminants into the water, such as plastics that are free from bisphenol A (BPA), and avoid parts that contain brass, which can leach lead.

4. Label Accuracy

Third-party certification verifies that all the claims in the product literature and on its labels are accurate and comply with testing results. The certification organization conducts a literature review to evaluate the product's data and label accuracy as part of its certification process.

Water Filter Certification Organizations

Three leading institutions provide water filtration system certification — NSF, the Water Quality Association (WQA), and IAPMO. These certification bodies provide multiple certifications that test a filter's functions. Knowing what each body certifies for and how they do it can help you decide which water filtration system will most benefit you and your family.

1. NSF Certification

Researchers at the University of Michigan founded NSF in 1944 to provide national sanitation and food safety standards. NSF is committed to improving public health with its strenuous product testing and certification programs. The organization now operates internationally and has expanded to test everything from appliances to food equipment. NSF's testing procedures are lengthy and thorough to ensure high product quality.

Not all NSF water filtration certifications are the same. Each NSF certification focuses on one component of the filtration system or one contaminant that the filter reduces. Just because a water filtration system is NSF-certified for one contaminant doesn't mean that it performs equally on other contaminants for which it has not been certified.

2. WQA Certification

Another way to find certified, reliable water filtration systems is to search for products with WQA certification. WQA was created in 1974 to improve water quality through research, testing, and certification. WQA is an industry leader in water treatment and conducts independent studies to help manufacturers meet independent standards.

Those products or companies with WQA certification attain what is called a Gold Seal Certificate. This certification tests the safety of a water filter's materials and its effectiveness at verifying the claims on its labels. WQA certification also measures whether the water filter will last under normal usage conditions.


The International Association of Plumbing and Mechanical Officials (IAPMO) is the foremost plumbing and mechanical product certification institution in North America. The agency's ANSI accreditation provides confidence in its certified products. IAPMO certifies products across North America to the applicable standards and provides certification assistance for manufacturers.

IAPMO certifies drinking water systems and water treatment units, shower filters, and microbiological purifiers. The Water Quality Platinum Seal is the agency's highest certification, which indicates that IAPMO has researched and tested the product to meet the established standards and codes.

What Are the Requirements for NSF Certification?

NSF certification is an extended process that involves meticulous testing to ensure the product meets quality standards. NSF can test many different types of water filtration systems, including:

  • Reverse osmosis (RO) systems
  • Distillation systems
  • Shower filters
  • Ultraviolet (UV) water systems
  • Carbon filtration systems
  • General water filtration products

The testing process requires multiple steps over a long time to ensure that all the data collected accurately represents the product's performance. Researchers from NSF evaluate the filters in their world-class laboratories, then inspect the manufacturing and assembly facilities. NSF also tests product performance directly off the assembly line as well as in a labsetting to ensure that the system the consumer receives is the same system that was certified.

There are many NSF certification types. The four main kinds are:

  • NSF Standard 42: This standard focuses on a water filter's ability to enhance the aesthetic effects of the water. Filters treated under NSF Standard 42 can treat contaminants like chlorine, sediment, or chloramine.
  • NSF Standard 53: Known as the Health Effects standard, Standard 53 measures a filter's effectiveness at reducing harmful contaminants like lead, arsenic, and methyl tert-butyl ether (MTBE) that can increase adverse health effects.
  • NSF Standard 401: With Standard 401 certification, a water filter is proven to reduce up to 15 specific contaminants, including pharmaceuticals, pesticides, herbicides, and BPA.
  • NSF Standard P231: Under Standard P231, NSF tests for bacteria, viruses, and live cysts. This standard measures how well a filter eliminates microbiological contaminants in a water system.

What Are the Requirements for a WQA Certified Water Filter?

For water filter manufacturers to obtain Gold Seal Certification for their products, they must first contact WQA to initiate the inspection of their water filtration systems. The Gold Seal product certification process requires that water filters pass several phases.

1. Performance Testing

WQA takes the water filtration systems a manufacturer wants to be tested and runs them through a series of rigorous evaluations in the WQA product testing laboratory. WQA tests water filtration systems and components for their compliance with specific standards, including:

  • NSF/ANSI 42: This standard covers claims of aesthetic contaminant reductions.
  • NSF/ANSI 53: NSF/ANSI 53 tests for a water filter's reduction of a wide range of contaminants that cause health-related issues.
  • NSF/ANSI 55: Testing for this standard covers UV water systems. Some RO water filters use UV light to sterilize microbes in the water.
  • NSF/ANSI 58: NSF/ANSI 58 covers RO systems and carbon filters that use a semi-permeable membrane to reduce contaminants.
  • NSF/ANSI/CAN 372: WQA uses this standard to test a water filter's ability to filter just lead from the water.

2. Literature Review

Once WQA tests for a water filter system's performance, researchers conduct a literature review to determine the accuracy of the manufacturer's claims. The literature review covers the water filter's installation manual, label, and datasheet.

3. Facility Audit

WQA then audits the manufacturer's facility to ensure that the certified products are the same ones the manufacturer is marketing and selling.

4. Certification

When the water filter passes all of these steps, it receives WQA certification and requires the water filter to bear the Gold Seal. When customers see a water filtration system with WQA Gold Seal certification, they can be confident that the product performs according to the manufacturer's claims.

How to Choose the Right Certified Water Filter

It can be challenging to pick a water filtration system that fits your needs. Fortunately, with some careful research, you can find a water filter that effectively treats contaminants and provides your home with cleaner, more healthful water. Follow these steps to choose the right certified water filter.

1. Understand Common Contaminants

Before you invest in a water filtration system, it's essential to understand the common water contaminants that might be present in your water. You can view your Consumer Confidence Report from your municipality. It is either posted on their website or sent to you with your bill each year.

2. Read About the Different Types of Filtration

Educate yourself on the available methods of water filtration to decide which type of system can best filter the types of contaminants that have been found in your water or that are of concern to you.

3. Determine Your Unique Needs

Consider these characteristics of water filtration systems before making your decision:

  • Performance: It's essential to consider how well a filtration system follows recognized water filter standards, especially those concerning the contaminants you are most concerned about. Whatever kind of filter you choose, look for one that has NSF certification or WQA certification.
  • Size: In addition to the high flow rate of water required, whole-house systems are generally designed to reduce the particulate matter in your water throughout your home, but do not normally reduce contaminants like lead and arsenic.
  • Versatility: Are you able to install it below the sink or on the counter? If you want to use the system for more than drinking, you'll need to find one that can operate at multiple points of use. Also, consider whether you need a reservoir.
  • Convenience: Some systems have limited water supplies due to the space taken up by holding tanks and reservoirs. Does a water filtration system limit you in how much water you can use at the same time? Can you wash your fruits and vegetables, cook, and use water for drinking and making beverages?
  • Maintenance: Some water filters require more maintenance than others. Determine how often you'll need to change the filter and whether the system requires additional power or chemicals.
  • Cost: Ensure you can find a water filter that fits your budget, from the initial purchase of the system to replacement filter costs. Some systems may be inexpensive, but you need to change the filter often. This can greatly add to the long-term cost of the system.

Multipure's Certified Water Filters

At Multipure, we offer industry-leading third-party certified drinking water systems for point-of-use and whole-house water filtration and purification. Every Multipure water filtration system demonstrates its effectiveness at reducing contaminants through NSF certification under the following standards and requirements:

  • NSF/ANSI Standard 42
  • Standard 53
  • Standard 401
  • Standard P231

These certifications mean that:

  • Multipure's products live up to the claims on their labels
  • Multipure's water filtration systems are backed by an independent quality assurance organization
  • Multipure isdedicated to providing filtration systems that meet quality and safety standards
  • Multipure has over 50 years of experience creating water filtration systems that effectively improve the healthfulness and taste of water

Multipure's drinking water filtration systems come in a wide range of filtration types and target many contaminants to provide you with healthful drinking water. Our systems include these products and more:

1. Aqualuxe

Multipure's Aqualuxe is a drinking water purifier that works at the sink to provide you with cleaner drinking water. You can install the Aqualuxe below the sink, on the countertop, or inline with your existing hardware for your convenience.

The Aqualuxe is certified to reduce PFOAs (forever chemicals), lead, mercury, arsenic, and over 85 other contaminants. Rated at 99.9999% (6-factor) bacteria and 99.99% (4-factor) virus reduction, this high-tech water purifier can significantly reduce contaminants from your drinking water, making it one of the few purifiers that do not require electricity.

2. Aquaperform

When you need powerful drinking water filtration and you are not concerned that there are high levels of bacteria and viruses in your water, turn to Multipure's Aquaperform drinking water filtration system. The Aquaperform utilizes a solid carbon block filter to treat various contaminants that affect your water's aesthetic and health qualities. The Aquaperform also includes arsenic-adsorptive media, which filters out Arsenic V — a dangerous contaminant used in industrial processes — asbestos, mercury, forever chemicals, lead, and other harmful contaminants.

Multipure's Aquaperform can be installed below-sink or on the counter, making it an excellent water filter for cleaner, better-tasting water wherever you get it. As with all Multipure products, the Aquaperform is built to last, providing cost-effective, powerful water filtration whenever you need it.

3. Aquaversa

The Multipure Aquaversa filtration system is one of the best mid-range water filters. This convenient and robust water filter is easy to use, with below-sink and on-the-counter configurations available. The Aquaversa is also an affordable option for people looking for versatile water filtration at a mid-range cost.

The Aquaversa uses carbon block technology to filter contaminants like lead, pharmaceutical products, chlorine, chloramine, and a wide range of other hazardous compounds. The Aquaversa's 750-gallon filter capacity is excellent for homeowners who want cleaner water for drinking, cooking, or providing better water for their pets.

4. Aquamini

Multipure's Aquamini is a travel water filter designed for on-the-go use. The perfect size for RVs, to take with you on vacation, or in areas with limited space like apartments or dormitories, Aquamini provides the convenience of a water filter pitcher with far greater filtration power. When you need water filtration in tight spaces, the Aquamini is an excellent choice.

The Aquamini has a 250-gallon filter capacity and uses a carbon block filter in its filtration process. This filter is NSF-certified to reduce a range of contaminants, including chlorine, lead, mercury, and more.

Get a Certified Water Filter Today

Multipure has been in the water filtration business for 50 years. We are dedicated to improving our environment and peoples' health through a range of water filtration systems that provide Americans with cleaner, safer water. Multipure's drinking water filters offer superior filtration to keep harmful contaminants out of your water. Our filters keep you and your family safe from a wide range of bacteria, viruses, chemicals, and more, giving you confidence in your drinking water.

With Multipure water filtration systems, you'll benefit from our unparalleled 90-day money-back guarantee and lifetime warranty on drinking water system housing. Contact us for more information or browse our selection of water filtration systems today. For Life. For You.