At a glance
| Chemical family | Per- and polyfluoroalkyl substance (PFAS) — an ultrashort perfluoroalkyl ether carboxylic acid (PFECA); a byproduct of fluoromonomer / GenX manufacturing at the Chemours Fayetteville Works. Three fluorocarbons and one ether oxygen make it among the smallest and most water-soluble PFAS known |
| CAS number | 674-13-5 (PubChem CID 5125273). IUPAC name 2,2-difluoro-2-(trifluoromethoxy)acetic acid. Molecular formula C₃HF₅O₃; molecular weight 180.03 g/mol; SMILES OC(=O)C(F)(F)OC(F)(F)F |
| Classification | No IARC classification. No US EPA Maximum Contaminant Level (not among the six PFAS in the 2024 National Primary Drinking Water Regulation). Not on the 29-PFAS UCMR 5 monitoring panel; not an analyte in EPA Methods 537.1 or 533. North Carolina studied it but issued no health guidance value Regulatory |
| Where you encounter it | Drinking water in the lower Cape Fear River basin (Wilmington, NC and downstream communities), historically supplied downstream of the Chemours Fayetteville Works discharge. Not a bedroom, mattress, air, or dust exposure — the documented route is contaminated tap water in one industrial-plume region |
| Sleep micro environment relevance | Indirect and outside the bedroom. PFMOAA is a drinking-water contaminant, not an off-gassing product, so it does not reach you through a mattress, pillow, or bedroom air. Its Atlas value is as a worked example of why a "passed PFAS testing" result can be incomplete when the test looks only for a fixed list of longer-chain compounds |
| Activated carbon capture | Not applicable to air/VOC capture. In drinking water, PFMOAA is poorly retained by granular activated carbon — it is small and highly soluble enough to break through carbon beds that remove longer-chain PFAS. High-pressure membranes (reverse osmosis) are the effective option. Inferred from the general ultrashort-PFAS treatment literature and reported carbon breakthrough at the Cape Fear utility; not a PFMOAA-specific measured removal efficiency |
Regulatory & certification status
Where PFMOAA stands across the major regulatory systems and the certifications a bedroom product might carry. Because PFMOAA is a water contaminant rather than a product ingredient, most rows read "no specific measure" — which is precisely the point. Where a jurisdiction has no measure that names it, that is stated plainly rather than left blank.
| European Union | No EU measure names PFMOAA individually. The EU Drinking Water Directive (2020/2184) sets a "Sum of 20 PFAS" parameter built around a defined list of mostly longer-chain perfluoroalkyl acids; ultrashort perfluoroethers such as PFMOAA are not on that list and generally fall outside routine PFAS monitoring. It would only be captured by a broad "PFAS Total" approach where laboratories are equipped to measure it. Regulatory — EUR-Lex |
| United States | No federal drinking-water standard. PFMOAA is not one of the six PFAS given a Maximum Contaminant Level in the EPA's 2024 National Primary Drinking Water Regulation, it is not on the 29-PFAS panel monitored under the fifth Unregulated Contaminant Monitoring Rule (UCMR 5), and it is not an analyte in EPA Methods 537.1 or 533 — the solid-phase-extraction methods that anchor most routine PFAS testing do not retain ultrashort, hydrophilic compounds like it. PFMOAA is not on the California Proposition 65 list. Regulatory — US EPA |
| Canada | No Canadian drinking-water measure names PFMOAA. Canada is moving to manage PFAS as a class (final State of PFAS Report, 2025; proposed Schedule 1 order in the Canada Gazette, Part I, 8 March 2025), which would encompass it in principle, but no value or listing specific to PFMOAA exists on the sources reviewed. Regulatory — Canada Gazette |
| Australia | No health-based guideline value for PFMOAA. The Australian Drinking Water Guidelines derive values for a small set of PFAS (PFOS, PFHxS, PFOA and PFBS in the 2025 update); ultrashort perfluoroethers such as PFMOAA are not among them, and PFAS more broadly are subject to AICIS information-gathering rather than a PFMOAA-specific measure. Regulatory — AICIS |
| United Kingdom | No UK measure names PFMOAA. The Drinking Water Inspectorate applies a tiered guidance approach to a defined list of individual PFAS; ultrashort perfluoroethers like PFMOAA are not on that list, and the sources reviewed do not document any GB registration or occurrence data for it. Regulatory — DWI |
| Certifications | None of the common bedroom certifications screen for PFMOAA. CertiPUR-US targets ozone depleters, specific flame retardants, heavy metals, formaldehyde, phthalates and low-VOC emissions in polyurethane foam. OEKO-TEX Standard 100 applies textile PFAS/total-fluorine screening to finished fabrics — a general PFAS check, not an ultrashort-ether-specific one. Neither, and no VOC-emissions certification such as GREENGUARD, is designed to detect a dissolved drinking-water contaminant. Industry — CertiPUR-US · OEKO-TEX |
| The 72-hour test window | Missed entirely. A short (~72-hour) chamber emissions test is built to capture off-gassing volatile organic compounds from a product; PFMOAA is a non-volatile, water-borne contaminant that never enters that pathway, so a chamber test does not — and cannot — see it. It is detected only by targeted aqueous LC-MS/MS methods capable of retaining ultrashort PFAS. Inferred — from the compound's non-volatile, water-phase profile versus the VOC focus of short chamber tests |
What it is
PFMOAA — perfluoro-2-methoxyacetic acid, CAS 674-13-5 — is a perfluoroalkyl ether carboxylic acid (PFECA), the same structural family as GenX (HFPO-DA), but far smaller. Its IUPAC name, 2,2-difluoro-2-(trifluoromethoxy)acetic acid, describes the whole molecule: a carboxylic-acid head, two fluorines, and a trifluoromethoxy group bridged by a single ether oxygen. The formula is C₃HF₅O₃ and the molecular weight is just 180.03 g/mol. That makes it one of the smallest PFAS anyone monitors — an "ultrashort" perfluoroether.
Size drives everything about how PFMOAA behaves. Legacy PFAS like PFOA and PFOS are long, partly oil-loving molecules that stick to surfaces, to activated carbon, and to proteins in the body. PFMOAA is short, strongly water-loving, and barely surface-active. In practice that means it moves through the environment with water almost unhindered, resists the treatment steps designed for longer chains, and — importantly — does not appreciably build up in the body the way the long-chain compounds do. It is a byproduct rather than a manufactured product: it forms during fluoromonomer and GenX-process chemistry, and for roughly four decades it was discharged, alongside GenX and related fluoroethers, from the Chemours (formerly DuPont) Fayetteville Works into the Cape Fear River.
Where you encounter it
The Cape Fear / Wilmington drinking-water plume
The documented exposure route for PFMOAA is drinking water, in one place: the lower Cape Fear River basin in North Carolina. The Chemours Fayetteville Works discharged PFMOAA and other fluoroethers into the river that serves as the drinking-water source for Wilmington and much of the lower basin. Because PFMOAA is so mobile in water, it traveled downstream efficiently and reached the intake for the Cape Fear Public Utility Authority (CFPUA), which supplies hundreds of thousands of people. This is not a diffuse, everywhere-at-once contaminant like legacy PFOA in dust — it is a concentrated, industrial-plume problem tied to a specific discharge and a specific watershed.
A case study in the limits of "the standard panel"
PFMOAA matters to anyone thinking about water safety because of a structural blind spot. When a utility or a homeowner says "we tested for PFAS and it passed," that test is almost always a fixed list — the six federally regulated PFAS, or the 29-analyte UCMR 5 panel, run on EPA Methods 537.1 or 533. Those methods rely on solid-phase extraction, which is very good at trapping longer-chain PFAS and poor at retaining tiny, water-loving molecules. PFMOAA slips through the extraction step, so it is not reported — even in a supply where it may be the single most abundant PFAS present by concentration. The compound that dominates the plume can be the one the standard test never looks for.
Not a bedroom, air, or dust exposure
PFMOAA does not off-gas, does not partition into household dust in any meaningful way, and is not applied as a textile or foam treatment. There is no mattress, pillow, or bedroom-air route. For readers outside the Cape Fear region, PFMOAA is catalogued here for completeness and as a worked example — not because it is likely to be in your water.
What the research says
Weed 2024 — how much is actually in the water
The clearest hard number comes from Weed and colleagues 2024 in Toxics, a community-engaged sampling study of the lower Cape Fear region that paired a 45-PFAS targeted panel with non-targeted analysis. Peer-reviewed The study measured PFMOAA up to 3,842 ng/L at a Wilmington sampling site, with other Wilmington samples in the tens-to-hundreds of ng/L range. For scale, the EPA drinking-water limit for PFOA and PFOS is 4 ng/L each — though, again, no such limit exists for PFMOAA. PFMOAA is repeatedly reported across this literature as one of the most abundant, often the single most abundant, PFAS by concentration in Cape Fear water; the cleanest peer-reviewed figure to anchor to is Weed's measured maximum, not a ranking claim.
McCord & Strynar 2019 — mapping the fluoroether family
McCord and Strynar 2019 in Environmental Science & Technology used a combined targeted and non-targeted high-resolution mass-spectrometry workflow to characterize the proliferation of perfluoroether acids in the Cape Fear — dozens of formulas and isomers traceable to the Fayetteville Works — and tracked their decline as source-control measures took effect. Peer-reviewed This work establishes PFMOAA's presence and its place within a large, plant-specific family of fluoroethers, and shows that discharge reduction at the source is what moves these concentrations.
Sun 2016 — the landmark detection
The foundational paper for the whole Cape Fear PFAS story is Sun and colleagues 2016 in Environmental Science & Technology Letters, which identified legacy and emerging PFAS — including the fluoroether replacements — as major drinking-water contaminants in the watershed. Peer-reviewed It is the origin point of the Wilmington fluoroether work and the reason researchers began looking for compounds like PFMOAA in the first place.
Kotlarz 2020 — why "in the water" is not "in the blood"
Kotlarz and colleagues 2020 in Environmental Health Perspectives reported serum biomonitoring for the GenX Exposure Study (n = 344 Wilmington residents), detecting several drinking-water-associated fluoroethers in blood and reconstructing a discharge history running from roughly 1980 to 2017. Peer-reviewed This is the crucial nuance for PFMOAA: the fluoroethers that accumulate in serum are the longer ones. PFMOAA is short and water-loving enough that it does not appreciably persist in blood, so it is a story about exposure in water — not about measured body burden. It should not be described as a compound found in people's blood.
CFPUA — breakthrough at the treatment plant
Since the Cape Fear utility brought granular activated carbon online (2022), CFPUA has reported that PFMOAA and a companion ultrashort compound, PFPrA, break through the carbon while roughly 65 other monitored PFAS — including GenX — are removed to near non-detection. Regulatory — utility reporting In the utility's framing, the ultrashort PFAS are the hardest to remove, and there is little, if any, health information available for PFMOAA specifically.
What helps reduce exposure
Reverse osmosis is the most effective household option in an affected supply. High-pressure membrane filtration (reverse osmosis, and to a lesser degree nanofiltration) is the treatment approach best suited to ultrashort, highly soluble PFAS; point-of-use reverse osmosis at the kitchen sink is the practical household version. Inferred from the general ultrashort-PFAS / reverse-osmosis literature; not a PFMOAA-specific measured removal efficiency Anyone relying on this for a specific contaminated supply should confirm performance for their system rather than assume it.
Ask the right question of your utility or lab. Because PFMOAA is not on the standard panels, a clean PFAS report does not rule it out. In an industrial-plume region, the meaningful question is whether the testing used non-targeted or ultrashort-capable methods — not simply whether "PFAS testing" was done.
What does NOT help
- Ordinary carbon pitcher and refrigerator filters. These are built around adsorption that works for larger molecules; PFMOAA's small size and high solubility let it pass through.
- Even purpose-built granular activated carbon. At the Cape Fear utility, PFMOAA has been observed breaking through carbon beds that remove longer-chain PFAS to near non-detection. Carbon is not a reliable barrier for this compound.
- Air purifiers, dust control, and bedroom source-control. PFMOAA is a water contaminant, not an airborne or dust-borne one. None of the bedroom-air interventions apply.
- Relying on a "passed PFAS testing" statement alone. If the test was a standard six- or 29-analyte panel, PFMOAA was never in scope — a pass is silent on it, not reassuring about it.
Open research questions
- Toxicology is nearly absent. There is no reference dose, no cancer classification, and no PFMOAA-specific epidemiology; the local utility notes little, if any, health information is available. What chronic low-level exposure means is genuinely unknown. Speculation — the health significance of PFMOAA exposure is uncharacterized
- Occurrence outside the Cape Fear basin is largely unknown, because few laboratories quantify ultrashort perfluoroethers at all. Whether PFMOAA is a Cape Fear peculiarity or a broader signal is an open empirical question. Inferred from the scarcity of methods capable of measuring it
- Municipal-scale removal of ultrashort PFAS — and the disposal of the reverse-osmosis reject brine that concentrates them — is an unresolved engineering and waste-management problem. Speculation
- Human toxicokinetics of ultrashort ether acids are poorly characterized compared with the longer fluoroethers that do accumulate in serum. Speculation
Where you meet Pfmoaa across your home
The same compound turns up in more than one place you live. Here's where it shows up in Embr — each links to the full breakdown for that part of your home.
What actually reduces your exposure
- PFMOAA is a drinking-water exposure concentrated in the Cape Fear / Wilmington NC region, not a bedroom source.
- It illustrates why 'our water passed PFAS testing' can mislead — it is on no standard panel.
- Reverse osmosis is the most effective household option; it breaks through granular activated carbon.
How it’s regulated, by region
| Region | Status | Detail |
|---|---|---|
| United States (EPA) | Unregulated | No MCL; not on UCMR 5 or EPA Methods 537.1/533. |
| North Carolina | Studied, no value | The state has studied PFMOAA but issued no health guidance value; the utility (CFPUA) reports little health information exists. |
Citations
- Weed RA, Campbell G, Brown L, May K, Sargent D, Sutton E, Emmons E, Aldridge C, Torkelson AS, Buse H, McCord J, Baker E, Kotlarz N, Hoppin JA, Knappe DRU, Guillette TC, Belcher SM (2024). Non-Targeted and Targeted Analysis of Per- and Polyfluoroalkyl Substances in the Lower Cape Fear River Region. Toxics, 12(6):403. DOI 10.3390/toxics12060403 Peer-reviewed — measured PFMOAA up to 3,842 ng/L in Wilmington water
- McCord J, Strynar M (2019). Identifying Per- and Polyfluorinated Chemical Species with a Combined Targeted and Non-Targeted-Screening High-Resolution Mass Spectrometry Workflow. Environmental Science & Technology, 53(9):4717-4727. DOI 10.1021/acs.est.8b06017 Peer-reviewed — Cape Fear fluoroether family and source-control tracking
- Sun M, Arevalo E, Strynar M, Lindstrom A, Richardson M, Kearns B, Pickett A, Smith C, Knappe DRU (2016). Legacy and Emerging Perfluoroalkyl Substances Are Important Drinking Water Contaminants in the Cape Fear River Watershed of North Carolina. Environmental Science & Technology Letters, 3(12):415-419. DOI 10.1021/acs.estlett.6b00398 Peer-reviewed — landmark Cape Fear PFAS detection
- Kotlarz N, McCord J, Collier D, Lea CS, Strynar M, Lindstrom AB, Bereman AA, Graham CY, Meyer TE, Cummings K, Hoppin JA, Knappe DRU (2020). Measurement of Novel, Drinking Water-Associated PFAS in Blood from Adults and Children in Wilmington, North Carolina. Environmental Health Perspectives, 128(7):77005. DOI 10.1289/EHP6837 Peer-reviewed — serum biomonitoring and discharge history; longer fluoroethers, not PFMOAA, accumulate in blood
- Cape Fear Public Utility Authority (CFPUA). PFPrA and other ultrashort-chain PFAS — utility water-quality reporting on the compounds that break through granular activated carbon at the Sweeney treatment plant, including PFMOAA and PFPrA. cfpua.org Regulatory — water-utility operator reporting
- US Environmental Protection Agency. Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) — the 29-PFAS national monitoring panel and EPA Methods 533 and 537.1, none of which include PFMOAA as an analyte. epa.gov/dwucmr Regulatory
- National Center for Biotechnology Information. PubChem Compound Summary for CID 5125273, Perfluoro-2-methoxyacetic acid (CAS 674-13-5; C₃HF₅O₃; MW 180.03). pubchem.ncbi.nlm.nih.gov Chemical identity / specification
Frequently asked questions
What is PFMOAA and where does it come from?
PFMOAA (perfluoro-2-methoxyacetic acid, CAS 674-13-5) is one of the smallest PFAS — a three-carbon perfluoroalkyl ether carboxylic acid with a single ether oxygen. In North Carolina it comes from the Chemours Fayetteville Works plant, which discharged PFMOAA along with GenX and other fluoroethers into the Cape Fear River — Wilmington's drinking water source — for decades. Its very small size and strong affinity for water make it behave very differently from legacy PFOA and PFOS: it is extremely mobile in water and poorly captured by both standard treatment and standard testing.
How much PFMOAA has been measured in drinking water?
Peer-reviewed community sampling in the lower Cape Fear region (Weed et al. 2024, Toxics) measured PFMOAA up to 3,842 ng/L at a Wilmington sampling site, with other Wilmington samples in the tens-to-hundreds of ng/L range. Across this body of work PFMOAA is repeatedly reported as one of the most abundant — often the single most abundant — PFAS by concentration in Cape Fear water. For comparison, EPA sets its drinking-water limits for PFOA and PFOS at 4 ng/L, though no such limit exists for PFMOAA.
Is PFMOAA regulated or tested for?
Generally no. PFMOAA has no EPA Maximum Contaminant Level, it is not on the 29-PFAS panel monitored under the fifth Unregulated Contaminant Monitoring Rule (UCMR 5), and it is not an analyte in EPA Methods 537.1 or 533 — the solid-phase-extraction methods that anchor most routine PFAS testing miss ultrashort, water-loving compounds like it. North Carolina studied PFMOAA but issued no health guidance value, and the local utility has noted there is little, if any, health information available for it. That gap — a compound that can dominate a contaminated supply yet appears on no standard panel — is exactly why it matters.
Can a water filter remove PFMOAA?
Ordinary filters do poorly, and even granular activated carbon — the workhorse for longer-chain PFAS — struggles: PFMOAA is so small and so soluble that it breaks through carbon beds, and it has been observed breaking through at the Cape Fear utility while other PFAS are removed to near non-detection. Reverse osmosis, a high-pressure membrane process, is the most effective option for affected household supplies. Note that PFMOAA is a drinking-water problem, not a bedroom or air-quality one, so household air and dust controls do not apply.
Related compounds
Embr is a sleep environment company researching the chemistry of the bedroom. See the methodology page for how this Atlas tags claims by evidence strength. For broader context on PFAS exposure pathways, see non-toxic bedroom and the 2026 PFAS brief.
Last reviewed 2026-07-14. If you find a factual error, contact us.