Air Emissions from PFAS-Laden and Fluorine-Free Firefighting Foams at Airports

PFAS are ubiquitous, persistent environmental contaminants which have garnered increased attention from regulators and public health officials in recent years. There has been very limited research into characterizing PFAS air emissions at airports, although prior studies have shown that significant amounts of volatile PFAS may be released into the air during aqueous film forming foam (AFFF) use and that inhalation may be an important exposure route. It is likely that inhalation of PFAS-containing vapor and aerosols contribute to PFAS levels detected in the serum of firefighters and first responders.

There are important data gaps in PFAS air emissions which have not been addressed by prior research. For example, ACRP Report 173 (Use and Potential Impacts of AFFF Containing Per- and Polyfluoroalkyl Substances (PFASs) at Airports) focused on soil and groundwater contamination, and did not address PFAS air emissions at airports and fire training facilities. There is a need to better understand potential releases to air from both an environmental and occupational health and safety standpoint. For example, little is known about typical volumes of AFFF used during fire training and incident response, associated release of PFAS to air, and whether certain aspects of ARFF activities may be adjusted to mitigate the air waste stream and exposure route.

In 2018, Congress directed the Federal Aviation Administration to develop rules for use of fluorine-free foams and transition away from foams containing PFAS. Current ARFF research projects are focused on finding an alternative firefighting foam that provides the same level of safety, while minimizing risks to the environment and human health. Similar to PFAS-containing foams, there is also a gap in the research related to air emissions from these flourine-free alternatives.

The objective of this research is to summarize best available information on PFAS air emissions and provide estimates of PFAS release to air during typical ARFF activities at airports and fire training facilities. The research product will provide clarity on potential environmental and health concerns and identify knowledge gaps related to PFAS air emissions, including inputs needed for future modeling and measurement studies. This study will also include consideration of potential air emissions from fluorine-free (PFAS-free) alternatives currently in development.

The following steps will be used to conduct the research:

• Compile available data on PFAS air emissions, with a focus on release during AFFF use

• Describe particle size distribution and partitioning behavior between the aqueous, vapor, and particle phases

• Estimate the volume of AFFF used during typical fire training and incident response and calculate associated PFAS concentrations in air

• Summarize what is known about short- and long-range transport and deposition of PFAS, including estimates of historical emissions and relevance to site characterization

• Gather available data and research outcomes for fluorine-free foam alternatives, including physical-chemical characteristics relevant to air quality modeling

The following cost estimate was developed based on prior experience with environmental fate and transport studies.

• Interviews and data compilation: $75,000
• Document findings: $150,000
• Report development: $225,000
• Total: $450,000

ACRP Report 173 (Use and Potential Impacts of AFFF Containing Per- and Polyfluoroalkyl Substances (PFASs) at Airports); Interstate Technology and Regulatory Council (ITRC) PFAS Technical Resources

Roth et al. (2020). Release of Volatile Per- and Polyfluoroalkyl Substances from Aqueous Film-Forming Foam. Environ. Sci. Technol. Lett. 7, 164-170.

Sunderland, et al. (2019). A review of the pathways of human exposure to poly-and perfluoroalkyl substances (PFASs) and present understanding of health effects. J. Exposure Sci. Environ. Epidemiol. 2019, 29 (2), 131−147.