Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

HFP kinetic dimer is volatile (VP, 34700 Pa at 20 °C) and has a water solubility of 649 µg/L at 22.3 °C. Its experimentally determined Henry's Law constant is 1.40E+07 Pa m³/mol (138 atm m³/mole) at 22 °C. HFP kinetic dimer is difficult to retain in aqueous solution, and the key fish, daphnia and algae toxicity studies used entirely closed systems without headspace throughout the test to obtain consistent concentrations, with analytical confirmation of test substance concentration. Test vessels at the highest test substance concentration intentionally contained a small amount of undissolved test material, although lower concentrations did not. Measurable concentrations of HFP kinetic dimer were present throughout the exposure period at higher concentrations, although concentrations fell below the limit of quantitation at lower concentrations. Loss of quantitation did not affect the results of any key study. The most sensitive species was Daphnia magna, for which 50% effect was exceeded in the dilution series. In the algae test, the 50% effect threshold was crossed between the two highest concentrations, with the aforementioned undissolved material present at the highest level. Saturated solutions did not attain 50% effect in the fish.

Two additional studies of fish toxicity were deemed not reliable. All of the key studies were performed in accordance with internationally-accepted test guidelines and Good Laboratory Practice (GLP) standards. Therefore, the studies are reliable, and the results suitable for purposes of Risk Assessment, Classification & Labeling, and PBT Analysis.

The primary fate of HFP kinetic dimer is expected to be photolysis to HF, TFA and iPFBA. These acids are highly soluble and are expected to reside ultimately in the aquatic compartment. HF and TFA are subjects of existing risk assessments.

Table 1, HFP kinetic dimer aquatic toxicity results

Species

Endpoint

Concentration

Results parameter

Reliability (Klimisch)

Fish

Danio rerio

96-hour LC50

> 12 µg/L ¹

>5 mg/L ²

mortality

1

Danio rerio

96-hour LC50

350 - 500 mg/L

mortality

4

Pimephales promelas ³

96-hour LC50

96-hour LC50

<1.0 mg/L ²

>1.0 mg/L ²

mortality

3

Invertebrate

Daphnia magna

48 -hour EC50

14 µg/L ¹

immobilization

1

Algae

Pseudokirchneriella subcapitata

72-hour EC50

72-hour EC10

72-hour NOEC

35 µg/L ¹

17 µg/L ¹

3.3 µg/L ¹

growth rate

2

1, Measured concentration

2, Nominal concentration

3, The first result is of direct addition of HFP dimer, the second result is of a water accomodated fraction