Given the widespread persistence and environmental impacts associated with the use of aqueous film forming foams (AFFF) containing per- and polyfluoroalkyl substances (PFAS), there is a need to develop PFAS-free foam alternatives to replace old technologies in fire-suppression operations. However, before the selection and implementation of PFAS-free foam alternatives, research must address their potential environmental impacts. The primary goal of this project is to assess the relative toxicity to aquatic species of PFAS-free AFFF alternatives. 

The project team will address the following questions: 

1. Are PFAS-free AFFF alternatives toxic to common aquatic species in North America (i.e. zooplankton, fish, and amphibians)?
2. If PFAS-free AFFF alternatives are toxic, what is their relative toxicity to the three focal species?
3. How does the toxicity of PFAS-free AFFF alternatives compare to the short chain AFFF formulations currently in use?
4. Do PFAS-free AFFF alternatives bioaccumulate within aquatic species and, if so, what is the distribution of bioconcentration factors across the focal species?

The project team will address the goal by conducting controlled laboratory experiments with zooplankton (water fleas, Daphnia magna), fish (fathead minnows, Pimephales promelas), and larval amphibians (gray treefrogs, Hyla versicolor). To facilitate comparisons across these species, the project team will standardize the treatments and experimental approaches. The experiments will focus on chronic exposures and address ecologically relevant endpoints (e.g., reproduction, growth, development). Importantly, the approach will be consistent with good laboratory practices that have been established from a previously funded SERDP project. High resolution mass spectrometry will be employed to add insight into what chemical(s) may be causing responses in the proposed toxicity studies by qualitatively evaluating chemical bioaccumulation.

The core outcome of these studies will be an improved understanding of the potential chronic effects of PFAS-free foam alternatives on the reproduction, growth, and development of aquatic species in North America. Importantly, the empirical results will address the toxicity and bioaccumulation of PFAS-free foam alternatives relative to short-chain AFFF formulations currently in use. Thus, the research will equip the DoD for making sound ecological risk assessments as they move forward in the selection process of suitable PFAS-free AFFF alternatives.