What is the Difference Between Microplastics and PFAS?

⚠ REGULATORY ALERT — APRIL 2024: On April 10, 2024, the EPA finalized the first-ever National Primary Drinking Water Regulation for six PFAS — establishing legally enforceable limits of 4 ppt for PFOA and PFOS, and 10 ppt for PFHxS, PFNA, and HFPO-DA (GenX). Simultaneously, PFOA and PFOS were designated as hazardous substances under CERCLA (Superfund). These are the most significant PFAS regulatory actions in history. See the Regulatory Landscape section below for full details.

Two Persistent Pollutants — One Major Environmental Challenge

Microplastics and PFAS (per- and polyfluoroalkyl substances) have both emerged as defining environmental contamination challenges of the 21st century. Both are persistent, ubiquitous, and found in environments ranging from the deepest ocean trenches to remote Arctic ice. Both have been detected in human blood, breast milk, and organs. Both are subjects of rapidly expanding regulation. But they are fundamentally different in their chemical nature, sources, analytical detection methods, and regulatory frameworks — and understanding those differences is essential for anyone involved in environmental testing, compliance monitoring, or contamination remediation.

This guide explains the key distinctions between microplastics and PFAS, describes how each is detected in laboratory settings, summarizes the current (2026) regulatory landscape, and explains the laboratory testing services available through ContractLaboratory.com for both contaminant classes. For detailed coverage of PFAS-specific testing services, see our guide to PFAS testing labs, and for a broader environmental water testing context, see our environmental water testing guide.

Microplastics vs PFAS: Key Differences at a Glance

Characteristic	Microplastics (and nanoplastics)	PFAS (per- and polyfluoroalkyl substances)
Chemical nature	Solid polymer particles; various plastics (PE, PP, PS, PET, PVC, nylon). Heterogeneous mixture of materials.	Synthetic organic chemicals; carbon-fluorine bond chemistry. >12,000 individual compounds across PFAA subclasses (PFCAs, PFSAs), fluorotelomers, PFAS precursors.
Size	Microplastics: <5 mm; Nanoplastics: <1 μm (some define <100 nm). Visible range to sub-cellular.	Molecular-scale chemicals: typically 4–18 carbon chain lengths. Not particulate — dissolved/ionized in water.
Primary sources	Breakdown of larger plastic debris (secondary); manufactured microbeads/pellets (primary); synthetic fiber shedding; tire wear particles; paint particles.	Industrial manufacturing; AFFF firefighting foam (military/airport contamination); non-stick cookware; food packaging; waterproof textiles; carpets; stain-resistant products.
Persistence	Extreme — carbon-fluorine bonds are among the strongest in chemistry. Decades to centuries in the environment. Many PFAS bioaccumulate and biomagnify up the food chain.	Very long — plastic polymers are biologically inert; they can persist for centuries. Not typically bioaccumulative in the same compound-specific sense as PFAS.
Human health concern	Synthetic organic chemicals; carbon-fluorine bond chemistry. >12,000 individual compounds across PFAA subclasses (PFCAs, PFSAs), fluorotelomers, and PFAS precursors.	Established: liver damage, thyroid disruption, immune suppression, developmental/reproductive effects, several cancers (kidney, testicular). PFOA MCLG of zero set by EPA — no safe level established.
Primary analytical methods	FTIR microscopy; Raman spectroscopy; Pyrolysis-GC-MS (Py-GC-MS); Optical microscopy/SEM; Flow cytometry (nanoplastics).	LC-MS/MS; EPA Methods 533, 537.1, 1633 (drinking water/multi-matrix); EPA Method 8327 (groundwater/wastewater). Solid-phase extraction (SPE) cleanup for water matrices.
Key regulatory milestones	EU microbeads ban (cosmetics, 2018 restricted); California SB-1422 microbeads ban; ISO 24187 (2023, vocabulary/sampling); EPA PFAS rule also drives microplastics co-monitoring.	EPA PFAS NPDWR (April 2024): 4 ppt PFOA/PFOS; 10 ppt PFHxS/PFNA/GenX; Hazard Index for mixtures. CERCLA hazardous substance designation (PFOA, PFOS, April 2024). EU PFAS universal restriction proposal (ECHA, ongoing).

What Are Microplastics (and Nanoplastics)?

Microplastics are solid plastic particles typically defined as smaller than 5 millimeters in their longest dimension — spanning sizes from just visible to the naked eye down to a few micrometers. They include the full range of synthetic polymer types used in manufacturing: polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polyamide (nylon), among others. Each polymer type has different physical characteristics and sorbs different chemical contaminants from the surrounding environment.

Primary vs Secondary Microplastics

• Primary microplastics: Particles intentionally manufactured at the microscale for industrial or consumer applications. Includes: nurdle pellets (industrial plastic production feedstock — a major source when spilled during shipping); microbeads in personal care products (exfoliating scrubs, toothpaste — now banned in EU and many US states); abrasive blasting media; synthetic fibers from textiles (washing releases microfibers directly to wastewater). An estimated 282 tons of primary microplastics are released annually from personal care products in the US alone.
• Secondary microplastics: Fragments produced by the physical, chemical, and UV degradation of larger plastic items — packaging, bottles, bags, fishing gear, agricultural films, and tire rubber. The world produces approximately 430 million metric tons of plastic annually, and the majority eventually fragments into secondary microplastics. Tire wear particles are among the most volumetrically significant secondary microplastic sources in terrestrial and freshwater environments.

Nanoplastics — The Emerging Frontier

Nanoplastics (NPs) are plastic particles smaller than 1 micrometer (1 μm) — often defined as below 100 nanometers (100 nm). They represent an emerging area of intense scientific and regulatory attention because their small size gives them properties distinct from microplastics:

• Cellular penetration: Nanoplastics are small enough to cross cell membranes, epithelial barriers, and potentially the blood-brain barrier — creating health exposure pathways not available to larger microplastics.
• Increased surface area-to-volume ratio: Makes nanoplastics more reactive and capable of sorbing greater concentrations of attached contaminants (heavy metals, persistent organic pollutants) per unit mass.
• Human tissue presence: Studies published 2022–2024 have confirmed plastic particles in human blood (Leslie et al., 2022, Nature Medicine), human placenta (Ragusa et al., 2021), lung tissue, testicular tissue, and coronary artery plaques. While not all identified particles were at the nanoscale, the findings demonstrate systemic distribution of plastic particles in the human body.
• Analytical challenge: Nanoplastics are below the size threshold reliably characterized by FTIR microscopy. Raman spectroscopy, Py-GC-MS, and emerging techniques such as field flow fractionation coupled to mass spectrometry are needed for detection and characterization at the nanoscale.

What Are PFAS? The “Forever Chemical” Family

PFAS — per- and polyfluoroalkyl substances — are a family of more than 12,000 individual synthetic chemical compounds that share the presence of fluorine-carbon bonds: one of the strongest bonds in organic chemistry, with bond dissociation energies of approximately 544 kJ/mol. This extraordinary chemical stability is both the source of PFAS’s industrial utility and the root cause of their environmental persistence — they do not break down in water, soil, heat, or biological systems under conditions typical of the natural environment.

The PFAS family is broadly organized into subcategories:

• Perfluoroalkyl acids (PFAAs): The most studied and regulated PFAS. Subdivided into perfluorocarboxylic acids (PFCAs, e.g., PFOA — perfluorooctanoic acid, C8; PFNA, C9; PFHxA, C6) and perfluoroalkyl sulfonic acids (PFSAs, e.g., PFOS — perfluorooctanesulfonic acid, C8; PFHxS — perfluorohexanesulfonic acid, C6; PFBS — perfluorobutanesulfonic acid, C4).
• Fluorotelomers: PFAS precursors used in surface coatings and firefighting foams that can degrade in the environment to produce PFOA and other PFCAs.
• Short-chain PFAS: C4-C7 compounds developed to replace long-chain PFOA and PFOS after their phase-out. While less bioaccumulative, short-chain PFAS are more mobile in water and groundwater, harder to remove by activated carbon treatment, and increasingly regulated. HFPO-DA (GenX, Chemours’s PFOA replacement) was found contaminating the Cape Fear River in North Carolina and is now regulated by the EPA 2024 rule.
• PFAS precursors: Compounds that are not themselves PFAAs but transform to PFAS through environmental degradation or biological metabolism. This means the total environmental burden of PFAS is substantially larger than measurable PFAA concentrations alone suggest.

AFFF — The Primary Source of PFAS Groundwater Contamination

Aqueous Film-Forming Foam (AFFF) — used since the 1960s for suppressing fuel fires at military installations, airports, oil refineries, and fire training facilities — is the most significant single source of PFAS groundwater contamination globally. AFFF formulations historically contained high concentrations of PFOS and PFOA. Decades of AFFF use and testing at military bases have contaminated groundwater at hundreds of US Department of Defense facilities and the surrounding communities that depend on that groundwater for drinking water. The EPA’s April 2024 designations of PFOA and PFOS as CERCLA hazardous substances were driven in large part by the legacy of AFFF contamination and the need for a legal framework to compel cleanup at contaminated sites.

Regulatory Landscape: 2024-2026 Developments

PFAS: EPA 2024 National Primary Drinking Water Regulation — The Most Significant PFAS Rule in History

⚠ Regulatory Alert: On April 10, 2024, the U.S. Environmental Protection Agency finalized the first-ever National Primary Drinking Water Regulation (NPDWR) for PFAS under the Safe Drinking Water Act. This establishes legally enforceable Maximum Contaminant Levels (MCLs) for six PFAS in drinking water:

• PFOA (perfluorooctanoic acid): MCL = 4 ppt (4 nanograms per liter). Maximum Contaminant Level Goal (MCLG) = zero — indicating no established safe level.
• PFOS (perfluorooctanesulfonic acid): MCL = 4 ppt. MCLG = zero.
• PFHxS, PFNA, HFPO-DA (GenX): MCL = 10 ppt each (individual MCLs).
• Hazard Index MCL = 1 (unitless) for mixtures of two or more of PFHxS, PFNA, HFPO-DA, and PFBS — accounting for dose-additive health effects when multiple PFAS co-occur.

Timeline for compliance: Initial monitoring by 2027; MCL compliance by 2029 (EPA is proposing to extend this to 2031 to allow more time for water systems to implement treatment). Best Available Technologies identified by EPA: granular activated carbon (GAC), anion exchange (AIX), nanofiltration (NF), and reverse osmosis (RO). The MCLs for PFOA and PFOS were confirmed as retained by EPA Administrator Zeldin in May 2025. EPA also announced its PFAS OUT program to assist utilities needing capital improvements.

The 4 ppt limit for PFOA and PFOS reflects that 4 ppt is the lowest concentration that can be reliably measured by approved analytical methods (the practical quantitation limit). The zero MCLG signals EPA’s position that no concentration of these compounds is considered safe; any remaining MCL limit is the lowest technologically achievable. EPA projects the rule will affect drinking water for approximately 100 million people and prevent over 9,600 deaths.

PFAS: CERCLA Hazardous Substance Designation (April 2024)

Concurrent with the drinking water rule, EPA finalized the designation of PFOA and PFOS as hazardous substances under CERCLA (the Comprehensive Environmental Response, Compensation, and Liability Act — the Superfund law). This designation means that releases of PFOA or PFOS above reportable quantities must be reported to federal authorities, and parties responsible for PFAS contamination can be held liable for Superfund remediation costs. This has enormous implications for AFFF-contaminated military sites, industrial facilities, and landfills, dramatically increasing demand for site characterization testing and remediation monitoring.

PFAS: EU Universal Restriction Proposal (Ongoing)

The European Chemicals Agency (ECHA) has been processing a universal restriction proposal that would restrict the manufacture, use, and placement on the market of the entire PFAS class of substances — rather than regulating individual compounds one by one. This proposed “universal restriction” approach, if finalized, would be the most comprehensive PFAS ban in history. Ongoing as of 2026, with industry consultation and risk assessment continuing. The EU’s REACH regulation has already restricted PFOS and PFOA.

Microplastics: Regulation in Progress

Microplastics regulation is less mature and more fragmented than PFAS regulation, but is accelerating:

• EU microbeads restriction (2018 restricted; ECHA 2022 restriction on intentionally added microplastics): The EU has restricted the addition of microplastics to products such as cosmetics, detergents, paints, agricultural products, and fertilizers where plastics are intentionally added and released to the environment. This regulation covers glitter, pellets, and microbeads.
• US state bans on microbeads: The Microbead-Free Waters Act of 2015 banned rinse-off cosmetics containing plastic microbeads at the federal level. California SB-1422 (2018) and similar state actions have extended coverage.
• ISO 24187 (2023): ISO published its first vocabulary standard for microplastics — establishing common definitions for research and regulatory consistency. Method standardization for environmental monitoring is an active ISO/CEN workstream.
• EPA monitoring: The EPA’s fifth Unregulated Contaminant Monitoring Rule (UCMR 5, 2021-2025) monitors 29 PFAS but does not yet include microplastics. Microplastics monitoring in US drinking water systems is under development.

Laboratory Testing Methods for Microplastics

Microplastics testing requires specialized analytical capabilities because the particles are heterogeneous in size, shape, color, and polymer type — and must be both identified (which polymer?) and quantified (how many particles per liter, gram, or cubic meter?) simultaneously. Environmental samples — water, sediment, soil, biological tissue, air — present complex matrices that require careful sample preparation to isolate microplastic particles from organic matter and other debris before analysis.

1. FTIR Microscopy (μFTIR): The Most Widely Used Method

Fourier Transform Infrared (FTIR) spectroscopy coupled with optical microscopy is the most widely used analytical method for microplastics identification in environmental samples. The technique works by irradiating the sample with infrared light and measuring the absorption spectrum — each polymer type produces a characteristic “fingerprint” spectrum that can be compared against reference libraries to confirm identity (PE, PP, PS, PET, PVC, nylon, etc.).

• μFTIR (micro-FTIR): The microscopy-coupled version allows chemical identification of individual particles as small as approximately 10–20 μm, combined with size and shape measurement. Automated analysis using high-throughput focal plane array (FPA) detectors dramatically increases analytical throughput.
• ATR-FTIR: Attenuated Total Reflectance FTIR is used for larger particles (>500 μm) or bulk analysis of sorted particles. Simpler to operate but cannot map particle-by-particle across a mixed sample.
• Limitation: FTIR cannot reliably characterize particles below ~10 μm and is essentially unable to detect nanoplastics.

2. Raman Spectroscopy: Better Resolution, Emerging as Preferred for Small Particles

Raman spectroscopy, like FTIR, identifies polymer types through vibrational spectroscopy but uses laser excitation and measurement of scattered light rather than infrared absorption. Raman offers several advantages for microplastics work:

• Higher resolution: Raman microscopy can characterize particles as small as approximately 1 μm — 10–20x better than FTIR — making it the preferred method for characterizing the smallest microplastics and beginning to address nanoplastics.
• Non-destructive: Unlike Py-GC-MS, Raman analysis does not consume the sample — allowing sequential analyses.
• Aqueous compatibility: Water is a poor Raman scatterer (unlike FTIR, where water strongly absorbs IR), making Raman better suited for direct analysis of aqueous environmental samples without complete drying.
• Confocal Raman imaging: High-speed line scan confocal Raman systems published in 2024 can analyze filter membranes for microplastics at dramatically increased throughput, addressing one of the key limitations of point-by-point scanning Raman systems.

3. Pyrolysis-GC-MS (Py-GC-MS): Quantitative Polymer Mass Analysis

Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC-MS) is a destructive technique that thermally decomposes polymer samples into characteristic molecular fragments that are then separated by gas chromatography and identified by mass spectrometry. Py-GC-MS cannot identify individual particle sizes (the sample is destroyed), but provides:

• Polymer mass quantification: Can determine the mass of specific polymers (e.g., total PE, PP, PS) in a sample — useful for bulk concentration estimates in sediment or biological tissue.
• Nanoplastics analysis capability: Because the technique is based on mass rather than optical imaging, Py-GC-MS can detect nanoplastics that are invisible to FTIR and Raman — provided the sample contains sufficient polymer mass.
• Sorbed chemical co-analysis: The “double-shot” Py-GC-MS approach can characterize chemicals attached to or absorbed by plastic particles (phthalates, bisphenol A, PAHs) in the same analytical run — providing insight into the chemical contaminant load carried by microplastics.

Leading analytical laboratories for microplastics testing typically offer both μFTIR (or Raman) for particle identification/counting and Py-GC-MS for polymer mass quantification — the combination providing the most complete analytical picture.

4. Additional Methods

• Optical microscopy and Scanning Electron Microscopy (SEM): Visual screening for particle count, morphology, and color classification. SEM with Energy-Dispersive X-ray Spectroscopy (SEM-EDX) can identify inorganic fillers in plastic particles. Used for preliminary screening before spectroscopic confirmation.
• Flow cytometry: Emerging method for nanoplastics detection in liquid samples using fluorescent staining of plastic particles — allows high-throughput counting but requires labeling and does not inherently identify polymer type.

Laboratory Testing Methods for PFAS

PFAS testing uses Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) as the gold standard analytical platform for all major EPA-approved methods. LC-MS/MS provides the sensitivity (parts per trillion or lower detection limits) and specificity (definitive compound identification by mass-to-charge ratio and fragmentation pattern) needed to differentiate and quantify individual PFAS compounds in complex environmental matrices. Solid Phase Extraction (SPE) is the primary sample preparation technique for concentrating PFAS from aqueous matrices before LC-MS/MS analysis.

Key EPA-Approved PFAS Analytical Methods

1. EPA Method 537.1 (2020): Determination of 18 selected PFAS in drinking water by Solid Phase Extraction (SDBL reversed-phase SPE) and LC-MS/MS. The primary method for drinking water compliance monitoring. Practical quantitation limits: 0.5–6.3 ng/L (ppt) depending on compound. Approved for UCMR 5 monitoring and the 2024 NPDWR compliance monitoring.
2. EPA Method 533 (2019): Determination of 25 PFAS (including short-chain PFAS better captured by anion exchange SPE) in drinking water by isotope dilution anion exchange SPE and LC-MS/MS. Complements Method 537.1 by better addressing short-chain PFCAs and PFSAs. Also approved for UCMR 5 and 2024 NPDWR.
3. EPA Method 1633 (finalized 2024): Analysis of 40 PFAS in 8 environmental matrices — surface water, groundwater, wastewater, soil, biosolids, sediment, landfill leachate, and fish tissue — by LC-MS/MS. Uses isotope dilution for improved accuracy in complex matrices. Published in January 2024. This is the primary method for environmental site characterization beyond drinking water, supporting Clean Water Act NPDES permits and CERCLA remediation monitoring.
4. EPA Method 8327 / SW-846: PFAS analysis in groundwater, surface water, and wastewater using LC-MS/MS. Used for Superfund site characterization and cleanup monitoring.

Sample collection requires PFAS-free containers (polypropylene or HDPE, laboratory-verified); preservation (chemical reagents added at collection for Methods 537.1 and 533); chilled shipping (≤10°C); and strict chain-of-custody procedures to prevent contamination from background PFAS in the laboratory environment — a significant analytical challenge as PFAS are ubiquitous in lab materials, clothing, and building materials.

Sources, Environmental Pathways, and Human Exposure

Where Microplastics Come From

The primary environmental pathways for microplastics: synthetic textile fiber shedding during washing (estimated 35% of primary microplastics in the ocean); tire rubber abrasion during driving (>1 million tons per year globally); plastic packaging fragmentation in landfills and open environments; agricultural plastic films (mulch films) degrading in soil; marine littering and debris; and industrial nurdle spills. Microplastics enter aquatic systems primarily through wastewater treatment plant effluent (where most particles pass through conventional treatment) and surface runoff.

Where PFAS Come From

PFAS contamination pathways: AFFF use at military bases and airports (historically the most significant contamination source; has created PFAS plumes in groundwater around hundreds of US DoD installations); industrial manufacturing and discharge (particularly from fluorochemical production facilities); landfill leachate from products containing PFAS; agricultural application of PFAS-containing biosolids (sewage sludge used as fertilizer can contain PFAS that migrate to groundwater); and consumer product degradation — non-stick coatings, food packaging, waterproof clothing all release PFAS during use or disposal.

The Interaction Between Microplastics and PFAS

Microplastics and PFAS are not merely parallel contaminants — they interact in the environment. Microplastic particles can sorb (adsorb and absorb) PFAS onto their surfaces, acting as transport vectors that concentrate and move PFAS through ecosystems. Laboratory studies have demonstrated that polystyrene and polyethylene microplastics sorb PFOS, PFOA, and other PFAS from surrounding water, potentially increasing local bioavailability of PFAS to organisms that ingest microplastics. This interaction means that comprehensive environmental site assessment in areas of co-contamination increasingly requires simultaneous testing for both classes of pollutants — a growing commercial testing category for environmental laboratories.

Health and Environmental Effects

Microplastics Health Effects

The health effects of microplastics in humans are an active area of research. Animal model studies show: physical blockage of digestive systems; inflammatory and oxidative stress responses to polymer particles; transfer of sorbed chemical contaminants (persistent organic pollutants, heavy metals, phthalates, BPA) at the site of microplastic deposition in tissue. Human studies documenting plastic particles in blood, lung tissue, placenta, arterial plaques, and testicular tissue (with some 2024 studies linking higher microplastic concentrations in arterial plaques to increased risk of cardiovascular events) are establishing the relevance of these findings to human health, though causal mechanistic studies are ongoing.

PFAS Health Effects

PFAS health effects are more extensively characterized than microplastics, given decades of occupational and community epidemiology. Documented associations include: liver damage and elevated liver enzymes; thyroid hormone disruption; immune system suppression (including reduced vaccine antibody response in children); developmental and reproductive effects (reduced birth weight, altered thyroid hormone levels in newborns, reduced fertility); elevated cholesterol; and several cancers — most strongly for kidney cancer and testicular cancer in workers and communities with high PFAS exposure. PFOA’s MCLG of zero by the EPA reflects the absence of an established safe exposure level.

Finding Accredited Testing Laboratories for Microplastics and PFAS

Microplastics and PFAS testing require specialized instrumentation and expertise not available at general environmental laboratories. For PFAS testing, laboratories must hold state certification under the EPA’s laboratory certification requirements for NPDWR compliance monitoring — and must use EPA-approved methods (537.1 and 533 for drinking water; 1633 for other matrices) with demonstrated performance. For microplastics, standardized methods are still evolving, but laboratories offering μFTIR, Raman spectroscopy, and Py-GC-MS capabilities provide the most comprehensive particle characterization.

ContractLaboratory.com connects environmental professionals, water utilities, industrial facility operators, government agencies, and litigation support teams with accredited environmental testing laboratories for PFAS and microplastics analysis. See also our specialized guide to PFAS testing labs, our environmental water testing guide, and our surface water and groundwater testing guide. Also relevant: environmental water quality testing and our PFAS in US tap water coverage.

Need Microplastics Testing?

Microplastics and PFAS are the defining persistent contaminants of our time — sharing the property of extreme environmental persistence but differing fundamentally in their chemistry, sources, analytical detection methods, and regulatory status. The EPA’s landmark April 2024 PFAS drinking water rule (4 ppt MCL for PFOA and PFOS) and CERCLA hazardous substance designations represent a regulatory inflection point that has dramatically accelerated testing demand for PFAS across all environmental matrices. Microplastics monitoring is following a parallel trajectory — with method standardization, regulatory frameworks, and analytical capabilities advancing rapidly. The 2024 discovery of nanoplastics in human coronary artery plaques and other tissues has elevated the urgency of research into plastic particle health effects.

Contract Laboratory connects environmental testing professionals, water utilities, industrial operators, remediation contractors, and government agencies with accredited environmental testing laboratories for PFAS and microplastics analysis. Submit a testing request or contact our team.

This article was created with the assistance of Generative AI and has undergone editorial review before publishing.

Frequently Asked Questions: Microplastics vs PFAS