The EPA is leading the national effort to understand PFAS and reduce PFAS risks to the public through implementation of its PFAS Action Plan and through active engagement and partnership with other federal agencies, states, tribes, industry groups, associations, local communities, and the public. 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 potential 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 effects.

On January 13, 2021 the EPA published the draft method OTM-45 to promote discussion of developing emission measurement methodologies and to provide regulatory agencies with potentially helpful tools. 

This method identifies and determines the concentration in mass per unit gas volume sampled of specific PFAS compounds in source emissions. Gaseous and particulate bound target pollutants are withdrawn from the gas stream isokinetically and collected in the sample probe, on a glass fiber or quartz filter, on a packed column of adsorbent material and in a series of impingers. The target compounds are extracted from the individual sample collection media. The OTM-45 train results in four (4) discreet sample extract fractions for analysis. The extracts are analyzed by LCMS/MS in the MRM detection mode. Quantification of each analyte is calculated using the isotope dilution technique. For QC purposes, the percent recoveries of the pre-extraction standards are calculated using the integrated peak areas of pre-analysis standard(s), which are Revision 0 (1/13/2021) added to the final extract and function as traditional internal standards, exclusively applied to the pre-extraction standards. The use of pre-sampling standards added to XAD-2 collection media prior to sampling and analyzed in the same manner as targeted PFAS compounds serves as an indication of the method’s quantitative capture efficiency. This method is not intended to differentiate between target compounds in particle or vapor fractions. This method uses isotopically labeled standards to improve method accuracy and precision.