PFOA PFOS Water Filter: What the EPA's 2024 Rule Means for Your Home

In April 2024, the U.S. EPA finalized the strictest drinking water limits ever set for PFOA and PFOS — 4 parts per trillion (ppt) each. These are the two most studied compounds in the PFAS family, and the 2024 rule is the federal government's definitive acknowledgment that they pose a real, measurable public health risk at levels commonly found in US tap water.

This guide explains what PFOA and PFOS are, why the EPA set the limits where it did, where these compounds come from, and specifically which filtration approaches remove them from household drinking water.

What Are PFOA and PFOS?

PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate) are long-chain per- and polyfluoroalkyl substances — synthetic chemicals characterized by an extremely strong carbon-fluorine bond that makes them resistant to heat, water, oil, and biological degradation.

PFOA was used extensively in the production of Teflon (PTFE) coatings and other fluoropolymers. PFOS was the active ingredient in Scotchgard fabric protectors and military firefighting foam (AFFF). Both were phased out of US production by 2002 (PFOS) and 2006 (PFOA) under voluntary EPA agreements, but their persistence means they remain in the environment, water systems, and human blood serum decades later.

The EPA has classified both PFOA and PFOS as likely human carcinogens. Epidemiological research has associated chronic exposure with:

• Kidney and testicular cancer

• Thyroid hormone disruption

• Elevated cholesterol

• Immune system effects (reduced vaccine antibody response)

• Developmental toxicity (low birth weight, developmental delays)

• Pre-eclampsia and pregnancy-induced hypertension

Where Do PFOA and PFOS Enter Drinking Water?

• Military and civilian airports — AFFF (aqueous film-forming foam) used in fire training and emergency response is the single largest source of PFOS contamination in groundwater near US military installations

• Industrial manufacturing sites — facilities that used or produced fluoropolymers

• Landfill leachate — PFAS-containing products in landfills leach into groundwater

• Biosolid-treated agricultural land — sewage sludge applied as fertilizer can contain concentrated PFAS; rainfall then transports it to groundwater

• General industrial discharge — paper mills, textile facilities, and other manufacturers using PFAS-containing processing aids

The USGS estimated in 2023 that PFAS is detectable in approximately 45% of US tap water samples. PFOA and PFOS are among the most commonly detected compounds.

The EPA's 2024 MCL Rule: What It Sets

Public water systems have until 2029 to comply. Many US households are currently consuming water that exceeds these limits and will continue to do so until infrastructure upgrades are complete. Point-of-use filtration is the most accessible immediate solution.

Which Water Filter Technologies Remove PFOA and PFOS?

The EPA's own technical guidance identifies the Best Available Technologies (BAT) for PFOA and PFOS removal:

1. Granular Activated Carbon (GAC)

Effective for long-chain PFAS including PFOA and PFOS. The mechanism is adsorption — PFAS molecules bind to the carbon surface. Performance for short-chain PFAS variants (PFNA, PFHxS, PFBS) is less consistent due to their weaker adsorption affinity for carbon.

2. Compressed Carbon Block

A denser, more uniform delivery of activated carbon that forces all water through the filtration matrix rather than allowing bypass channeling around loose granules. Provides longer contact time, more consistent PFOA and PFOS removal, and adds physical microplastic interception as a secondary benefit. The EPA-recommended approach for point-of-use pitcher format filtration.

3. Reverse Osmosis

Highly effective for all PFAS classes. Requires under-sink installation and generates wastewater. The most comprehensive approach for households with high PFAS contamination levels.

4. Anion Exchange Resin (AER)

Effective for long-chain PFAS; variable performance for short-chain variants. More common in whole-house or under-sink applications than pitcher format.

For Pitcher Buyers: Compressed Carbon Block Is the Standard

In pitcher format, compressed carbon block is the EPA-endorsed technology for PFOA and PFOS reduction. When evaluating pitchers specifically for PFAS removal, look for:

• Compressed carbon block (not just granular activated carbon)

• Independent third-party lab testing for PFOA and PFOS specifically — at Eurofins, IAPMO, or equivalent accredited labs

• Coverage for short-chain PFAS (PFNA, PFHxS, PFBS) not just PFOA and PFOS

• Glass or steel pitcher housing — filtering PFAS out of water and then storing it in plastic is an incomplete solution

Duryn's Approach to PFOA and PFOS

Duryn's GravityPlus™ cartridge uses compressed activated carbon block — the EPA's recommended BAT for PFOA and PFOS in point-of-use applications — as its core filtration medium. The cartridge is tested for PFOA, PFOS, and short-chain PFAS compounds at Eurofins (ISO-accredited EU laboratory) and IAPMO (globally recognized water certification body) — independent testing not conducted or controlled by Duryn.

The pitcher housing is borosilicate glass and medical-grade 316L stainless steel. No plastic water-contact surfaces. What the GravityPlus™ filter removes from your water doesn't come back from the container storing it.

Duryn is aligned with EN 17093 (European drinking water treatment standard), NSF/ANSI 42 & 53, and NSF/ANSI 372 & 61. It's the pitcher built for the regulatory reality of 2024 onwards.

Ready to filter PFOA and PFOS with independent lab-verified confidence?

Discover the Duryn One Water Filter Pitcher — compressed carbon block, borosilicate glass, stainless steel. Eurofins and IAPMO tested for PFOA, PFOS, and short-chain PFAS.