Perfluorinated Compounds (PFCs)
What are they?
Perfluorinated compounds (PFCs) are a large class of industrial chemicals that were first reported as a global environmental contaminant in 2001 (Giesy and Kannan 2001). The chemical class has more recently been termed “Perfluoroalkyl and Polyfluoroalkyl substances” or PFAS and includes thousands of individual chemicals (U.S. Environmental Protection Agency 2019).
What are they used for?
The chemicals are used in a variety of industrial processes and everyday consumer products. PFAS are added to consumer products to increase stain resistance (e.g. sofas, carpets), increase water resistance (e.g. tents, rain jackets) and produce a non-stick surface (e.g. cookware, food packaging). In addition to these everyday products, PFAS are also used in firefighting foams, and in the automotive, semiconductor and construction industries.
Where can they be found?
Due to the variety of uses of PFAS, levels have been measured in numerous environmental samples including drinking water, groundwater, soil, marine mammals, birds, and humans. Unlike other global contaminants (such as PCBs and dioxins) the chemicals are not lipophilic. However, they do exhibit a long half-life in humans (years) and slowly degrade in the environment (National Institute of Environmental Health Sciences 2016).
Why are they important?
Research on long-chain PFAS such as perfluoroctane sulfonate (PFOS) and perfluorooctanoate (PFOA) have demonstrated potential adverse health effects in animal studies. There has been less research on replacement PFAS (short-chain) and overall health risks are still being determined. The global distribution of PFAS, observed animal toxicity, and widespread public concern has caused the U.S. EPA to create an action plan to better understand the implications of PFAS contamination (U.S. Environmental Protection Agency 2019). PFOS has also been added to the Stockholm Convention on Persistent Organic Pollutants (POPs).
Chemistry Matters Consulting Services and Expertise
The global contamination of PFAS in the environment poses a complex environmental, legal, and public health challenge. The expertise of the Chemistry Matters team can be applied to many of those challenges.
PFAS contaminated drinking water and groundwater poses a considerable remediation challenge. New strategies are being developed to effectively clean up or treat the contaminated sites. Communities with potentially impacted water supplies may be faced with the substantial burden of cost to remediate these sites or develop water treatment systems. Identifying potential responsible parties and recouping costs requires science-based decisions that can withstand legal scrutiny. The Chemistry Matters team has extensive experience to assist in each aspect of an environmental forensic investigation including planning, legal chain-of-custody protocols, data analysis, receptor modelling (source apportionment), expert witness services, and scientific communication.
The potential health impacts from PFAS exposure have not been fully characterized. To gain a better understanding, biomonitoring studies can provide important clues into exposure routes and associated health risks. At Chemistry Matters, we understand the importance of data quality and how that may impact decisions made from biomonitoring data. A properly designed sampling strategy must consider both control and reference samples. Our team has expertise in handling large data sets for data analysis, interpretation and multivariate analysis. We have in depth knowledge in the use and statistical interpretation required for the proper use of the United States NHANES data which can be used as a reference for normal human exposure. Chemistry Matters has developed a statistical analysis tool for appropriate population statistics and effective visualization of NHANES data (biomonitoring) with Statvis Analytics Inc.
Fate and Transport
The scientific knowledge of chemical fate and transport in the environment is important to understand and identify sources of contamination. The mobility, transport, uptake, metabolism and toxicity of PFAS can all be impacted by carbon chain length, chemical structure and other functional groups. Both linear and branched isomers of PFOS (and other PFAS) have been found in the environment and both PFOS and PFOA can be formed as byproducts or from the degradation of other PFAS. Through chemical fingerprinting and statistical analysis the team at Chemistry Matters can provide clients with sound scientific evidence to establish fate, transport, and source identification.
Giesy, J. P. and K. Kannan (2001). “Global Distribution of Perfluorooctane Sulfonate in Wildlife.” Environmental Science & Technology 35(7): 1339-1342.
National Institute of Environmental Health Sciences (2016). Perfluorinated Chemicals (PFCs). Research Triangle Park, NC 27709: 4.
U.S. Environmental Protection Agency (2019). EPA’s Per- and Polyfluoroalkyl Substances (PFAS) Action Plan. www.epa.gov/pfas.