Legislation has mandated the phase out of per- and polyfluoroalkyl substances (PFAS) in fire extinguishing agents. Consequently, novel PFAS-free firefighting formulations (F3s) have been developed and require validation of their performance and impacts. This study performed multi-taxa ecotoxicity tests and inherent biodegradability tests with a suite of seven candidate F3s and a reference, PFAS-containing aqueous film-forming foams (AFFF) product. The overarching goal was to evaluate the toxicity and biodegradation potential of F3s to facilitate selection of appropriate replacement products.

For the toxicity studies, tested taxa included three aquatic species (green algae, Raphidocelis subcapitata; midge larvae, Chironomus dilutus; and fish, Pimephales promelas) and two terrestrial species (bobwhite quail, Colinus virginianus, and brown anole, Anolis sagrei). Acute and chronic studies were performed to assess the effects of F3s and a reference product (AFFF) on survival, growth, reproduction, and development.

For biodegradation studies, a modified Zahn-Wellens test was performed to assess the inherent biodegradability of the products over 28 days.

Aquatic and Terrestrial Receptors Were Tested

In the aquatic species, both acute and chronic toxicity tests indicated higher toxicity of several of the tested F3 relative to the reference product. In the bobwhite quail studies, similar effects were observed between several of the tested F3s and the reference product. Finally, in reptiles, several of the tested F3 were more toxic than to the reference product. Importantly, biodegradation tests indicated good overall biodegradability of all tested F3. Specifically, chemicals constituents of several F3s dropped to non-detectable levels within the 28-day testing period, some as early as seven days into testing. PFAS in the reference product showed significant increases over the biodegradation testing period.

Although some effects were observed in laboratory tests with animals exposed to F3s, field exposure, outside of an emergency releases or spills, is unlikely and ingredients in F3s rapidly degrade. Taken together (i.e. similar toxicity but lower persistence), these data suggest that the risk to wildlife is generally lower for F3s than legacy AFFF. Successful implementation of this research holds profound implications for improving the management of PFAS, directly addressing mission readiness by safeguarding the warfighter and communities. (Project Completion - 2024)

Fuller, N., J.G. Suski, S. Lanasa, M.K. Chanov, D.K. Jones, D.L. Haskins, K.A. Quinlin, M.A. Wigren, J.T. Hoverman, Y.J. Choi, M.S. Sepulveda, L.S. Lee, G.R. Lotufo, A. Kennedy, L. May, A. Harmon, T. Biber, N. Melby, D.W. Moore, P.B. Key, K.W. Chung, E.F. Wirth, and T.A. Anderson. 2024. Chronic Toxicity of PFAS-Free Firefighting Foams to Aquatic Organisms. Environmental Toxicology & Chemistry, 43(11):2436-2454. doi.org/10.1002/etc.5979.

Gharehveran, M.M., A.M. Walus, T.A. Anderson, S. Subbiah, J. Guelfo, M. Frigon, A. Longwell, J.G. Suski. 2022. Per- and polyfluoroalkyl substances (PFAS)-free aqueous film forming foam formulations: Chemical composition and biodegradation in an aerobic environment. Journal of Environmental Chemical Engineering, 10:208953. doi.org/10.1016/j.jece.2022.108953

Hossain, F., N.M. Dennis, A. Karnjanapiboonwong, S. Subbiah, A.S. Longwell, J.G. Suski, C.J. Salice, and T. A. Anderson. 2023. Evaluation of the Chronic Reproductive Toxicity of a Fluorine-Free Firefighting Foam and a Short-Chain Fluorinated Foam to Northern Bobwhite Quail (Colinus virginianus). Environmental Toxicology & Chemistry, 43(1):211-221. doi.org/10.1002/etc.5765. 

Hossain, F., N.M. Dennis, S. Subbiah, A. Karnjanapiboonwong, J.L. Guelfo, J. Suski, and T.A. Anderson. 2022. Acute Oral Toxicity of Nonfluorinated Fire-Fighting Foams to Northern Bobwhite Quail (Colinus virginianus). Environmental Toxicology & Chemistry, 41(8):2003-2007. doi.org/10.1002/etc.5398. 

Jones, D.K., K.A. Quinlin, M.A. Wigren, Y.J. Choi, M.S. Sepúlveda, L.S. Lee, D.L. Haskins, G.R. Lotufo, A. Kennedy, L. May, A. Harmon, T. Biber, N. Melby, M.K. Chanov, M.L. Hudson, P.B. Key, K.W. Chung, D.W. Moore, J.G. Suski, E.F. Wirth, and J.T. Hoverman. 2022. Acute Toxicity of Eight Aqueous Film-Forming Foams to 14 Aquatic Species. Environmental Science & Technology, 56(10):6078-6090. doi.org/10.1021/acs.est.1c03776