Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS)


Technical BRIEF
INNOVATIVE RESEARCH FOR A SUSTAINABLE FUTURE
www.epa.gov/research
Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS)
Methods and guidance for sampling and analyzing water and other environmental media
Background
Per- and polyfluoroalkyl substances (PFAS) are a group of
synthetic chemicals that have been in use since the
1940s. PFAS are found in a wide array of consumer and
industrial products. PFAS manufacturing and processing
facilities, facilities using PFAS in production of other
products, airports, and military installations are some of
the contributors of PFAS releases into the air, soil, and
water. Due to their widespread use and persistence in the
environment, most people in the United States have been
exposed to PFAS. There is evidence that continued
exposure above specific levels to certain PFAS may lead to
adverse health. The U.S. Environmental Protection
Agency (EPA) will continue to partner with other federal
agencies, states, tribes, and local communities to protect
human health and, where necessary and appropriate, to
limit human exposure to potentially harmful levels of
PFAS in the environment.
EPA's methods for analyzing PFAS in environmental media
are in various stages of development. The Agency is
working to develop validated analytical methods for
groundwater, surface water, wastewater, and solids,
including soils, sediments, and biosolids.
Drinking Water
Analysis using EPA Method 537.1
To assess for potential human exposure to PFAS in
drinking water, EPA's validated method 537.1 will ensure
that both government and private laboratories can
accurately and consistently measure 18 PFAS in drinking
water, which is a critical step for estimating people's
exposure and potential risk to PFAS. EPA Method 537 was
first published in 2009 to initially determine 14 different
PFAS. In 2018, the method was updated to include 4 more
PFAS including the GenX chemical hexafluoropropylene
oxide dimer acid (HFPO-DA).
Short-chain PFAS in drinking water method
EPA is finalizing an additional drinking water method that
is specific to "short chain" PFAS [none greater than C12),
that includes perfluorinated acids, sulfonates,
fluorotelemers and mono/poly perfluorinated ethers.
U.S. Environmental Protection Agency
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EPA expects to have a draft method for
non-potable water by fall 2019.
Many of these couldn't be analyzed using 537.1 due to
physicochemical disparities. The method is expected to be
published in the summer 2019 and is anticipated to
include a total of 25 PFAS (14 of the 18 PFAS in 537.1 plus
an additional 11 "short chain" PFAS).
Health Advisories
In May 2016, EPA issued drinking water health advisories
for two types of PFAS: perfluorooctanoic acid (PFOA) and
perfluorooctanesulfonic acid (PFOS). EPA's health
advisories are non-regulatory and non-enforceable, and
are intended to provide technical information to state
agencies and other public health officials on health
effects, analytical methodologies, and treatment
technologies associated with drinking water
contamination.
Method Development & Validation
Currently, there are no validated standard EPA methods
for analyzing PFAS in surface water, non-potable
groundwater, wastewater, or solids. For non-drinking
water samples, some U.S. laboratories are using modified
methods based on EPA Method 537. These modified
methods have no consistent sample collection or
analytical guidelines and have not been validated or
systematically assessed for data quality.
EPA/600/F-17/022e Updated February 2019

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To address this sampling and analytical gap, EPA formed a
cross-Agency method development and validation
workgroup to provide sampling guidance and validated
methods for sample types other than drinking water. The
workgroup will develop SW-846 analytical methods for
quantifying PFAS analytes. The method development
process will occur in a phased approach.
Phase I
EPA labs tested an existing direct injection
analytical protocol for preparing and analyzing 24 PFAS
analytes in groundwater, surface water, and wastewater
effluent. Labs completed this phase in winter 2017, and
results warranted moving to Phase II.
Phase II
In October 2018, seven external labs began
validating the direct injection method. Data packages
from the participating laboratories are currently being
reviewed and statistically analyzed. The target timeframe
for publishing a validated SW-846 direct injection method
(Draft Method 8327) for public review is summer 2019.
EPA has also drafted a solid-phase extraction/isotope
dilution (SPE-ID) method in collaboration with the Naval
Seas Systems Command Laboratory Quality and
Accreditation Office and SGS-AXYS.
The SPE-ID protocol (Draft Method SW-846 8328) will be
externally validated, with a target start time in summer
2019. Draft Method 8328 will include solid matrices in
addition to non-drinking water aqueous matrices. This
draft method may be split into different preparation
methods (e.g. aqueous and solid samples) and a final
determinative analytical method. In addition to the 24
analytes under draft Method 8327, EPA plans on adding
analytes for the 8328 Method (or series of methods) to
include recent additions to drinking water method 537.
Developing Sampling & Storage Methods
EPA ran time-based studies on degradation or loss of
target analytes during sample storage (45 days) and
assessed the effects of different sample vessel materials
(e.g., plastic, glass) on analyte recovery. Based on these
studies, the SW-846 methods under development will
utilize PFAS-free, high-density polyethylene containers;
whole sample preparation; and sample holding times of
28 days. EPA will also develop guidelines for field
sampling, which are critical for minimizing sample
contamination and optimizing data quality for site
characterization and remediation.
Due to the widespread use of PFAS, many materials
normally used in field and laboratory operations contain
PFAS. For example, polytetrafluoroethylene products
(tubing, sample containers, and sampling tools) are often
used in sampling; however, since these products can
contain PFAS, they cannot be used in sampling for PFAS.
In addition, many consumer goods brought to a sampling
site may contain PFAS that can contaminate samples.
Field sampling and laboratory hygiene protocols are
critical to ensuring that testing results reflect actual PFAS
levels in the analyzed media. The Interstate Technology
and Regulatory Council has summarized site
characterization, sampling precautions, and analytical
method issues and options through their fact sheet series.
Contacts
Technical Contacts
•	Chris Impellitteri, impellitteri.christopher@epa.Eov
•	Schatzi Fitz-James, fitz-james.schatzi@epa.gov
•	Cynthia Caporale, caporale.cynthia@epa.gov
Communications Contact
•	Michelle Latham. Iatham.michelle@epa.gov
Additional Information
PFAS in Your Environment: epa.gov/pfas
Clean-Up Information: clu-in.org/
EPA Method 537.1:
cfpub.epa.qov/si/si public file download.cfm?p
download id=537290&Lab=NERL
SW-846 (Compendium):
epa.gov/hw-sw846/sw-846-compendium
PFOA & PFOS Drinking Water Health Advisories:
epa.aov/around-water-and-drinkina-water/
drinkinq-water-health-advisories-pfoa-and-pfos
Third Unregulated Contaminant Monitoring Rule
(UCMR3): epa.gov/dwucmr/third-unregulated-
contaminant-monitorina-rule
Interstate Technology and Regulatory Council
PFAS Fact Sheets: pfas-l.itrcweb.org/fact-sheets/
EPA's Water Research: epa.gov/water-research
Disclaimer: This document is for informational purposes
only. Any mention of or reference to commercial products,
processes, or services by trade name, trademark,
manufacturer, or otherwise does not imply an endorsement
by the U.S. Government or the U.S. Environmental
Protection Agency and shall not be used for advertising or
product endorsement purposes. EPA does not endorse any
commercial products, services, or enterprises.
U.S. Environmental Protection Agency

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