PFAS in Air; Establishing a successful test program to meet your data quality objective (DQO)
PFAS (Per- and polyfluoroalkyl Alkyl Substances) consist of thousands of chemicals widely used for their unique chemical and physical properties In January 2020 EPA’s Toxic Release Inventory (TRI) program identified 172 PFAS compounds which were added to the program. Until recently with improved analytical capabilities to detect low level PFAS in the environment and on-going research has brought attention to exposure that may lead to adverse human health effects. Toxicological research has raised concerns regarding the bio-accumulative nature of some PFAS. As a result, our understanding of PFAS and the risk associated is rapidly evolving.
EPA’s ongoing research led to the 2020 legislation which was passed by Congress affecting facilities where PFAS is expected in air emissions. In January 2021 the Air Emissions Measurement Center (EMC), which is the EPA hub for stationary source air emissions test methods and procedures released OTM-45 (Other Test Method) with the guidance for the collection and analysis of PFAS from sources air emissions. These methods have been reviewed by the EMC to support guidance with technical review of field, analytical, quality assurance and quality control procedures. Moving forward the guidance of OTM-45 will improve emissions measurements methodologies including in the sample collection and analytical aspects of the method.
Test Method OTM-45 is comparable to EPA Method 23 (Dioxins & Furans) isokinetic sampling. The testing and sample challenges begins with the recommendation not to use polytetrafluoroethylene (PTFE). To improve data quality when PFAS containing equipment cannot be eliminated additional steps to improve QA/QC are required, including additional equipment rinse and field blanks, and field duplicates. These additional steps are important to support low level detection limits and data validity. Samples are analyzed by LC MS/MS Isotope Dilution methods.