EPA Test Methods for PFAS

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Pace® was one of the first environmental labs approved by the U.S. EPA for PFAS, and we’re continuing that tradition by working with the agency to validate new, more advanced methods.

EPA Test Method 537.1

Matrix: Drinking Water

Compounds: 18

An EPA validated method, Method 537.1 was developed to replace Method 537 and is commonly used for drinking water compliance. In addition to analyzing for the 14 compounds covered by Method 537, Method 537.1 also analyzes for four replacement PFAS*, including 11Cl-PF3OUdS, 9Cl-PF3ONS, ADONA, and HFPO-DA (also known as Gen X).

*Replacement PFAS are short-chain, potentially less toxic PFAS compounds used to replace PFAS with known toxicity, such as PFOA and PFOS.


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EPA Test Method 533

Matrix: Drinking Water

Compounds: 25

Method 533 expanded the number of PFAS compounds that can be analyzed for in drinking water samples. Method 533 also utilizes isotope dilution, providing additional quality control for accuracy of reporting, especially at ppt levels. Method 533 does not replace Method 537.1, but together, the tests can be used to analyze for 29 PFAS compounds. Method 533 is also commonly used for drinking water compliance, and both Methods 533 and 537.1 will be required for UCMR 5 compliance.

Pace® is an approved UCMR 5 testing laboratory. You can learn more about the program and our services on our UCMR 5 program page.

EPA SW-846 Method 8327

Matrices: Ground & Surface Waters, Wastewater, Leachate, Wastewater Sludge & Biosolids

Compounds: 24

Published as final in June of 2021, Method 8327 is designed for non-potable waters, including surface water, groundwater, and wastewater. Pace® will seek certification when it becomes available. However, as currently defined, Method 8327 has a number of limitations, and we will continue to offer PFAS by Isotope Dilution and Draft Method 1633.

EPA Draft Method 1621

Matrices: Aqueous Matrices

Compounds: Adsorbable Organic Fluorine (AOF)

EPA Draft Method 1621 is described by the EPA Office of Water as a “Screening Method for the Determination of Adsorbable Organic Fluorine (AOF) in Aqueous Matrices by Combustion Ion Chromatography (CIC).” As drafted, this method can quantify adsorbable organic fluorine at the parts-per-billion level in most aqueous matrices. Pace® was chosen to perform the single-lab validation for Draft Method 1621 and will also be participating in the multi-lab validation phase expected to take place summer of 2022, and we are participating in the multi-lab validation phase currently underway.

EPA Draft Method 1633


Compounds: 40

Published in August of 2021, Draft Method 1633 closely resembles PFAS by Isotope Dilution and can quantitate 40 compounds across a wide range of solid and aqueous matrices. Method 1633 will likely replace all laboratory-specific SOPs as well as state and DOD-specific guidance and methods. Method 1633 will also play a vital role in the EPA’s efforts to study, monitor, and regulate PFAS in nearly all matrices and regulatory programs except drinking water.  Pace® is participating in the multi-lab validation of this method.

EPA Draft SW-846 Method 8328


Compounds: 40

The EPA is also collaborating with the DOD to develop SW-846 Method 8328, a test method for analyzing PFAS in solid waste. Once finalized, this method is expected to be very similar to Draft Method 1633, with additional SOPs for solid waste and to support RCRA compliance. The method will also be widely used for DOD projects with the addition of QSM controls.


Matrices: Air

Compounds: 50

OTM (Other Test Methods) are EPA test methods that have not yet gone through the agency’s rule-making process, but are urgently needed to support agency initiatives. OTM 45 was issued as draft in January 2021 by the EPA’s Emission Measurements Center (EMC) to promote consistency and best practices when sampling and analyzing PFAS in stack emissions. Pace® uses OTM 45 to analyze stack emissions for its industrial clients.


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We can test for PFAS in both solid and aqueous matrices, including potable and non-potable waters, soils, and biota.

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We’re on the leading edge of science, working with EPA, DOD, ASTM, and others to develop new methods for analyzing PFAS.