Considerations for PFAS Fingerprinting and Allocation

Environmental Forensics
Oral Presentation

Prepared by L. Cook1, K. O'Reilly2, T. Saba1
1 - Exponent, One Mill and Main, Suite 150, Maynard, MA, 01754, United States
2 - Exponent, 15375 SE 30th Place, Suite 250, Bellevue, WA, 98007, United States

Contact Information:; 978-760-9000


With the long history and diverse array of perfluoroalky and polyfluoroalkyl substance (PFAS) uses and chemical compositions, forensic evaluation and fingerprinting PFAS sources in the environment is uniquely challenging. In addition to the complex chemical composition of products, some PFAS undergo chemical transformations and differential transport in the environmental which alter the chemical profiles. Forensic fingerprinting and allocation of PFAS contamination requires evaluation of many lines of evidence to determine likely sources. During this presentation, the types of evidence needed to evaluate sources of PFAS will be addressed. The first evaluates the chemical composition of the contamination with a focus on assessing the PFAS product process (electrochemical fluorination or telomerization), chain length distribution (long vs short chain), presence/absence of newer replacement substances, branched isomer profiles, and other non-PFAS chemical markers. Additional evidence includes review of historic site information, evaluation of known PFAS uses and products, assessment of parties in the area and their PFAS use, and local factors affecting fate and transport of contaminants at the site. Along with these multiple lines of evidence, forensic chemists can evaluate the fitness and limitations of the chemistry data. With assessment of all available evidence and evaluation of the fitness and comparability of available data, successful forensic evaluation of PFAS sources and allocations can be achieved.