Trihydrogen trifluoro[phosphato(3-)-O]borate(3-)

Short-term toxicity to aquatic invertebrates

Additional information

No study data is available for the test substance. Similar to all coordination complexes of boron trifluoride with organic and inorganic species (like alcohols, ethers, amines, sulfuric acid, sulfuric dioxide, etc) the complex of boron trifluoride and phosphoric acid is extremely water sensitive and reacts even with moist air. In the instantaneous reaction with water as a first step phosphoric acid and boron trifluoride dihydrates are formed. The latter undergoes further rapid hydrolysis to boric acid, fluoboric acid and tetrafluoroborate. Acute effects on daphnids were studied using the read across substances boric acid (CAS No 10043-35-3), phosphoric acid (CAS No 7664 -38 -2) and sodium tetrafluoroborate (CAS No 13755-29-8).

key (boric acid)

The 48-h acute toxicity of the read across substance boric acid (CAS No 10043-35-3) to Daphnia magna was studied under static conditions. Daphnids were exposed to solvent control and nominal concentrations of 54, 91, 151, 252, 420 and 700 mg B/L. Mortality/immobilisation was observed daily. Animals were not fed during the study.

No mortality was observed up to 54 mg B/L. All animals were found dead in the two highest concentration groups. The 48-hour LC50 was determined to 133 mg B/L (Gersich, F.M., 1984).

key (phosphoric acid)

The 48-h acute toxicity of the read across substance orthophosphoric acid (CAS No 7664-38-2) to Daphnia magna was studied under static conditions according to OECD guideline 202. 10 Daphnids per concentration were exposed to solvent control and test chemical at concentrations of 10, 18, 32, 56 and 100 mg/L. Each concentration was tested in duplicate. Immobilisation and other adverse effects were observed daily. Immobilisation was deteceted if daphnids were unable to swim for approximately 15 seconds after gentle agitation. Immobilisation was not observed up to 56 mg/L. 30% of the daphnids were found immobilised in the highest test group of 100 mg/L. Conclusively, the EC50 is above 100 mg/L (study report, 2010).

supporting (tetrafluoroborate)

In the present publication (Bernot et al., 2005), the acute toxicities of imidazolium-based Ionic Liquids (ILs) to the water flea Daphnia magna was investigated. Acute toxicity of ILs (48-h median lethal concentration [LC50] value) was determined using standard U.S. Environmental Protection Agency (U.S. EPA) protocols. The acute effects of imidazolium-based ILs on survival of the crustacean Daphnia magna and their chronic effects on number of first-brood neonates, total number of neonates, and average brood size were studied. The toxicity of salts with Na+ as the cation and PF6-, BF4- as anions was also tested in order to determine if the imidazolium cation or the various anions influenced toxicity. Lethal concentrations of imidazolium ILs with various anions (X) ranged from a median lethal concentration (LC50) of 8.03 to 19.91 mg/L, whereas salts with a sodium cation (Na +X) were more than an order of magnitude higher (NaPF6 LC50, 9344.81 mg/L; NaBF4 LC50, 4765.75 mg/L). Thus, toxicity appeared to be related to the imidazolium cation and not to the various anions (e.g., Cl, Br, PF6, and BF4). Finally, the LC50 of sodium tetrafluortoborate being 4765.75 mg/L is the relevant read across information.

supporting (Public references from 1977 -1991, focus on boron)

Several daphnid values are reported, including several studies of high quality. Acute values (24-48 hour EC50) range from 73 to 226 mg B/L for Daphnia magna. Data for other daphnids are reported but are of low reliability, also reported acute values in the 100-180 mg B/L range for Ceriodaphnia dubia and Simocephalus vetulus.  Maier and Knight (1981) reported that water hardness had no effect on the acute toxicity to the midge Chironomus decorus, with a 48-hour EC50 of 1376 mg B/L.

Based on the results of the acute ecotoxicity tests using daphnids, LC50/EC50 was above 100 mg/L, indicating no toxicity triggering classification and labelling.