An Evaluation of the Chronic Oral Toxicity of Fomtec Enviro USP, a Fluorine-Free Firefighting Foam, to Northern Bobwhite Quail (Colinus virginianus)

Long chain per- and poly-fluoroalkyl substances (PFAS) have been the standard active chemicals used in aqueous film forming foams (AFFF) since the mid-1960s. Some characteristics of PFAS are environmental persistence, ability to resist degradation at high temperatures, bioaccumulation, and the ability to travel long distances from the point of release. As an alternative, non-fluorinated firefighting foams are being introduced with the intent of having a decreased ecological and environmental impact. In a chronic study, northern bobwhite quail (Colinus virginianus) were used to test the ecotoxicity of one candidate (non-fluorinated) foam. Fomtec Enviro USP is a fluorine-free commercial AFFF used primarily for extinguishing Class B hydrocarbon fuel fires. Following a photostimulation phase, breeding pairs of quail were exposed over 60 days to 0.01%, 0.1%, and 0.25% Fomtec in drinking water. Endpoints of the study included survival, growth, and reproductive output. Average water consumption per day over the 60 days of exposure was compared, control birds which consumed 34.1 ± 1.2 mL/per day compared to 30.0 ± 2.3 (0.01% Fomtec exposure), 33.4 ± 1.6 (0.1% Fomtec exposure), and 37.4 ± 0.2 (0.25% Fomtec exposure). Water consumption was used to determine the average daily intake (ADI) for SDS (0.05, 0.15, and 0.31 mg/kg/day for the 0.01%, 0.1%, and 0.25% Fomtec exposures, respectively) and DGMBE (0.48, 6.54, and 18.37 mg/kg/day for the 0.01%, 0.1%, and 0.25% Fomtec exposures, respectively). Over the 60 days, control females laid an average of 56 ± 0.8 eggs compared to 28 ± 9 (0.01% Fomtec exposure), 51 ± 4 (0.1% Fomtec exposure), and 56 ± 2 (0.25% Fomtec exposure). Hatching success was not significantly different among treatment groups (80 ± 3.6%) and within normal reproduction parameters. Within treatment groups the hatching success (%) for control birds was 80 ± 4, 79 ± 9 (0.01% Fomtec exposure), 83 ± 5 (0.1% Fomtec exposure), and 78 ± 16 (0.25% Fomtec exposure). Chick survival (%) at 21 days following adult oral exposure in drinking water for control birds was 89 ± 4, for treatment birds the survival was 83 ± 12 (0.01% Fomtec exposure), 91 ± 4 (0.1% Fomtec exposure), and 87 ± 9 % (0.25% Fomtec exposure). In adult birds, a change in weight from initial weight to weight at the end of the 60-day exposure to Fomtec Enviro USP was evaluated between male and female birds. Male bird weight was not affected to a significant level between control and treatment birds. Female birds saw an increase in weight from initial (203.3 ± 5 g) to final weight for control (256.4 ± 7 g) and the 0.25% Fomtec exposure (259.9 ± 3 g). Female birds exposed to Fomtec at 0.01% and 0.1% did not have a significant weight gain from initial to final weight. Weight gain was expected over the course of the study, since the birds were still growing and female birds are the heaviest during breeding season while males are the lightest. Water intake increases to produce eggs and the energy needs for reproduction; all factors that could have impacted the weight of the female birds over the course of the chronic study. Adult biometric parameters including left and right wing, head, left and right tarsals, liver weight, relative liver weight and lipid content were not significantly different with the exception of 0.25% Fomtec exposure female birds left tarsal (larger). For chick biometric parameters, control chicks had larger left and right wings and left and right tarsals but a smaller liver and smaller relative liver weight. A smaller liver could be the result of parental exposure to Fomtec Enviro USP and the chicks having to metabolize components of Fomtec Enviro USP that were transferred to the egg. These parameters did not lead to less weight gain of control chicks compared to treatment chicks from hatching through 21 days. Our findings on chronic toxicity in this avian model help to fill data gaps for these non-fluorinated foam products, many of which have little toxicological information.