Acute Toxicity of Eight Aqueous Film-Forming Foams to 14 Aquatic Species

Abstract

Researchers have developed numerous per- and polyfluoroalkyl substances (PFAS)-free aqueous film-forming foam (AFFF) formulations to replace PFAS-containing AFFF used for fire suppression. As part of the Department of Defense’s Strategic Environmental Research and Development Program (SERDP), we examined the direct lethal effects of seven PFAS-free AFFF and a PFAS-containing AFFF on 14 aquatic species using a series of lethal concentration (LC50) tests. We assessed the LC10, LC50, and LC90 values using log–logistic and logit analyses. Across all aquatic species tested, we discovered that exposure to at least one PFAS-free AFFF was more or as toxic as exposure to the PFAS-containing AFFF. For most cases, National Foam Avio F3 Green KHC 3% and Buckeye Platinum Plus C6MILSPEC 3% were the most and least toxic formulations, respectively. Moreover, we found consistency among results from multiple experiments using the same minnow species (Pimephales promelas) and among closely related taxa (e.g., daphnids, amphibians). Lastly, the LC50 values for AFFF formulations trended lower for tested marine species as compared to those of freshwater species. These results dramatically increase the current knowledge on the potentially toxic effects of AFFF but also highlight the need for additional research and the development of new PFAS-free AFFF that are more “ecologically friendly” than those containing persistent PFAS.

Ecotoxicity Evaluation of Fire-Extinguishing Water from Large-Scale Battery and Battery Electric Vehicle Fire Tests

“…PFAS are of a significant environmental concern since they are highly persistent, − can bioaccumulate in organisms, and transport through maternal transfer. − In work by Sunderland et al, the human exposure to PFAS and its epidemiologic evidence for impact on cancer, immune function, metabolic outcomes, and neurodevelopment are reviewed.…”

Sunrise of PFAS Replacements: A Perspective on Fluorine-Free Foams

“…■ ENVIRONMENTAL IMPACTS OF F3: CURRENT RESEARCH Research into the environmental impacts of F3 is a relatively new field, with the first peer-reviewed papers on the topic published only in the past couple of years. At present, the available ecotoxicological data on foam formulations are limited to studies on acute toxicity in 14 freshwater and marine aquatic species, 55 acute toxicity in one terrestrial invertebrate (Caenorhabditis elegans), 56 acute oral toxicity in one avian species (northern bobwhite quail), 57 phytotoxicity in one plant species (Brassica rapa), 58 and aerobic biodegradation. 59 This limited body of research suggests that further investigation is needed to fully understand the environmental impacts of these foams, particularly when compared to the long-term effects of AFFF.…”

“…In some cases, research has found that F3 can demonstrate equal or greater acute toxicity than C6 AFFF, particularly for aquatic species, which are often more sensitive than terrestrial species and mammals. 67 Some studies have also focused on the sublethal growth and reproductive impacts of these foams on worms 68 and plants. 45 However, it is important to distinguish between toxicity tests on a foam, formulation, or product and toxicological assessments based on individual components or constituents.…”

“…In some cases, research has found that F3 can demonstrate equal or greater acute toxicity than C6 AFFF, particularly for aquatic species, which are often more sensitive than terrestrial species and mammals . Some studies have also focused on the sublethal growth and reproductive impacts of these foams on worms and plants .…”

Evaluation of the Chronic Reproductive Toxicity of a Fluorine‐Free Firefighting Foam and a Short‐Chain Fluorinated Foam to Northern Bobwhite Quail (Colinus virginianus)

“…Using an up‐and‐down test procedure (OECD, 2008), Hossain et al (2022) observed northern bobwhite quail LD50s for all foams with ≥1500 mg formulated product/kg body weight. Further, these same foams have recently undergone an evaluation for acute toxicity in aquatic organisms; in 11 of 14 species, most of the fluorine‐free foams had greater acute toxicity than PFAS‐containing foam (Jones et al, 2022).…”