reaction mass of 1,1,1,2,2,3,3,4,4,5,5,6,6,6-tetradecafluoro-hexane and 1,1,1,2,2,3,3,4,5,5,5-undecafluoro-4-(trifluoromethyl)pentane

Endpoint summary

Additional information

FC-72 is a member of the Perfluorinated Organic Chemicals, C5-C18 category. Because these substances exhibit similarity in their physicochemical properties and toxicological properties in mammals, and because available data indicates that parent molecules are not reactive toward biological molecules and cannot undergo bioactivation by normal enzymatic processes, they can be considered members of a chemical category. A reliable fish toxicity study of FC-72 is available. No mortality was observed to P. promelas at a nominal concentration of 1000 mg/L, with undissolved material present in the test aquarium throughout the entire exposure period. Readacross is used to fill data gaps for other endpoints. Recent, high-quality studies are available for toxicity to aquatic invertebrates of several category members including perfluoroheptanes [PFHp], thus providing the highest quality data set. Loading rates were approximately 1000 mg/L except in the case of FC-770, which had a loading rate of 100 mg/L. In all cases, no toxicity was observed at the limit of solubility. Measured maximum achievable test concentrations ranged from 1.74 µg/L (PTBA) to 408 µg/L (PMM). In addition to the aquatic invertebrate tests noted above, PFHp and perfluoro-C6,8-furans, pyrans and acyclic ethers (FC-77) were not toxic to D. magna in limit tests conducted at loading rates of 1000 mg/L and 1500 mg/L, respectively (no analytical determination of concentrations). This lack of aquatic invertebrate toxicity across members of the category provides additional support for use of readacross to fill data gaps for other toxicological and ecotoxicological endpoints. In addition to the aforementioned fish toxicity test on FC-72, category members FC-770 and FC-77 were not acutely toxic to fish. FC-770 was tested using D. rerio. After 96-hours, no toxicity was observed from a water-soluble fraction prepared at 100 mg/L. The mean measured concentration during the test was 0.096 mg/L. FC-77 was tested using P. promelas. In this case, test chambers were prepared at an initial loading rate of 1000 mg/L. Exposure concentrations were not measured, however, the test material could not be entirely dissolved and was observed in the test chambers throughout the experiment. Other category members including PMM showed no toxicity to fish in limit tests with nominal concentrations ranging from 750 to 2700 mg/L. In algae tests, PMM and FC-770 were not toxic to P.subcapitata at measured maximum achievable test concentrations of 0.583 mg/L and 0.15 mg/L, respectively (loading rates of 1000 and 100 mg/L). Category members PFHp, PMM and FC-770 were not toxic to activated sludge respiration in limit tests conducted at 1000 mg/L. Analytically determined concentrations for other category members are not reasonable to use for readacross because of divergent solubilities. Lack of toxicity at the limit of solubility is read across qualitatively to FC-72. The water solubility of FC-72 was determined to be 84.1 µg/L, which is accepted as the basis for estimating the FC-72 aquatic toxicity endpoints.

A long-term study of aquatic invertebrate toxicity was conducted with category member PTBA with nominal concentrations only (no analytical determination of test substance). The study utilized a loading rate which assured that saturation of the water phase was stably maintained between media replacements, and no chronic toxicity was observed. Lack of long-term toxicity at the limit of water solubility is used for readacross to FC-72. While long-term aquatic toxicity endpoints are not required for FC-72, the readacross result is used to inform the PBT Analysis and in deriving PNEC values.

Please see IUCLID section 13 for a matrix of aquatic toxicity data for members of the Perfluorinated Organic Chemicals C5-C18 category.