Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Short-term ecotoxicity testing of FC-770 has revealed no acute toxicity to aquatic organisms or activated sludge. Toxicity test results based on loading rates showed EC50 values greater than 100 mg/L for Danio rerio (zebrafish, 96-h mortality), Daphnia magna(water flea, 48-h immobilization), and Pseudokirchneriella subcapitata (green algae, 72-h growth inhibition), as well as an EC50 >1000 mg/L to activated sludge (primarily domestic, 3-h respiration inhibition). FC-770 is highly volatile and has a very low water solubility. The fish, invertebrate, and algae tests were conducted using closed test chambers to maintain the FC-770 in solution, but the test substance was not present at quantifiable levels after 24 hours in spite of this fact. The tests were nevertheless classified as reliable without restriction since all reasonable steps had been taken to keep the test substance in solution within the context of the method as published at the test date. The analytical results provide further evidence as to the difficulty of performing toxicity tests, especially long-term toxicity tests, with FC-770. We have proposed waiving testing long-term toxicity of FC-770 to fish and to invertebrates based on lack of exposure in the aquatic compartment. As noted in the short-term test results and in accord with experimental results for vapor pressure, water solubility and Henry’s Law constant, a long term presence of FC-770 in the aqueous compartment is not likely and long-term toxicity testing will not provide relevant or useful information on safety of FC-770. Further, based on projected uses of FC-770, all releases are to the atmosphere, with little or no tendency of FC-770 to partition to aquatic systems. Lack of significant exposure in the aquatic environment is demonstrated by PEC/PNEC ratios substantially less than one, as determined during exposure modeling for environmental compartments.

FC-770 is a member of the Perfluorinated Organic Chemicals, C5-C18 category, but is used almost entirely as a source substance for read-across. In the interest of simplifying the technical dossier and registration, FC-770 is being submitted as an individual substance. Please see IUCLID section 13 for a full matrix of data for members of the Perfluorinated Organic Chemicals C5-C18 category.