PFAS in Tap Water: Effective Filters and EPA/NSF Guidelines

What Are PFAS and Why Remove Them from Tap Water?

Per- and polyfluoroalkyl substances (PFAS) are a collective term for thousands of man-made chemicals. These chemicals have been used for decades in various industrial and consumer products due to their resistance to water, oil, and stains. Examples include non-stick cookware, water-resistant clothing, and firefighting foams. PFAS are often called ‘forever chemicals’ because they break down very slowly in the environment, found in soil, water, air, and even in the bodies of humans and animals. (Source: EPA)

According to the U.S. Environmental Protection Agency (EPA), exposure to PFAS may be linked to various health issues, including certain cancers, liver damage, reduced immune system function, and developmental delays. These concerns have increased interest in methods for removing PFAS from tap water.

Key Technologies for Removing PFAS from Tap Water

The primary water filter technologies known to effectively remove PFAS from tap water are Reverse Osmosis (RO) and Granular Activated Carbon (GAC) filters. NSF International explains that both of these technologies can be effective for PFAS reduction. (Source: NSF International)

1. Reverse Osmosis (RO) Systems

Reverse Osmosis systems work by forcing water under high pressure through a semi-permeable membrane. This membrane allows water molecules to pass through while filtering out most contaminants, including PFAS, which are then flushed away. RO systems are known to be highly effective at removing very small particles, making them very efficient for PFAS removal. They are typically installed under the sink.

2. Granular Activated Carbon (GAC) Filters

Granular Activated Carbon filters remove PFAS from water by adsorbing PFAS molecules onto the porous surface of carbon particles. GAC filters can be found in various forms, such as refrigerator filters, pitcher filters, and whole-house filtration systems. The effectiveness of a GAC filter can vary depending on factors like the filter’s size, the type of carbon used, and the contact time of the water with the filter.

The Importance of NSF Certification: How to Choose a Filter

The most reliable way to confirm that a water filter effectively removes PFAS is to check for certification from an independent organization like NSF International. NSF International is a non-profit organization that develops public health and safety standards and certifies products. (Source: NSF International)

NSF tests and certifies specific water filters to ensure they meet performance criteria for PFAS reduction. Key NSF/ANSI standards related to PFAS removal include:

• NSF/ANSI 53: For activated carbon filters that reduce specific health-related contaminants, including some PFAS.
• NSF/ANSI 58: For reverse osmosis systems that reduce total dissolved solids (TDS) and other contaminants, including PFAS.
• NSF/ANSI 401: For filters that reduce emerging contaminants, including some PFAS.
• NSF P473: For filters that reduce specific PFAS compounds.

When purchasing a water filter, it is crucial to check the product’s description or packaging for these NSF certification marks and a clear statement of which standard verifies its PFAS removal performance. NSF certification assures that the product has achieved its stated performance through independent testing.

Water Filter Selection Guide

When choosing a water filter for PFAS removal, consider the following factors:

1. Check for NSF Certification: This is the most critical step. Always confirm that the filter you intend to purchase is certified according to PFAS removal standards such as NSF/ANSI 53, 58, 401, or P473. (Source: NSF International)
2. Choose Filter Technology: Reverse Osmosis (RO) systems are highly effective at removing a wide range of contaminants, but they can be complex to install, may waste water, and can have a higher cost. Granular Activated Carbon (GAC) filters are generally simpler to install and more cost-effective, but the type and amount of PFAS they can remove may vary depending on the filter type.
3. Filter Capacity and Replacement Schedule: Check the filter’s capacity and recommended replacement schedule. Filters must be replaced periodically to maintain their performance. Failing to replace a filter on time can reduce its effectiveness or even cause contaminants to be released.
4. Installation and Maintenance: Consider the ease of installation and maintenance requirements of the filter system. Some products can be self-installed, while others may require professional assistance.
5. Budget: Account for not only the initial purchase cost but also long-term maintenance expenses, such as filter replacements, to choose a product that fits your budget.

Conclusion

To effectively remove PFAS from tap water, it is crucial to choose products with scientifically proven filter technology and reliable certification. Reverse Osmosis (RO) and Granular Activated Carbon (GAC) filters are key technologies effective for PFAS removal, and NSF International certification is an important indicator that helps consumers make informed decisions. Before purchasing a water filter, always verify NSF certification and carefully select a system that meets your household’s needs and budget.