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Ecotoxicological information

Toxicity to soil microorganisms

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Description of key information

Since dihydrogen hexafluorotitanate rapidly dissociates into fluoride, hydrogen and titanium ions upon dissolution in the environment, and only fluoride but not hydrogen and titanium ions will remain as such in solution, it can be assumed that toxicity (if any) will be driven by the fluoride anion. Therefore, the lowest available NOEC of 106 mg F/kg for the long-term toxicity (63 days) of potassium fluoride to NO3-mineralisation (nitrification) is read-across to dihydrogen hexafluorotitanate resulting in a NOEC of 152.4 mg/kg. 

Key value for chemical safety assessment

Long-term EC10 or NOEC for soil microorganisms:
152.4 mg/kg soil dw

Additional information

Dihydrogen hexafluorotitanate

Since dihydrogen hexafluorotitanate rapidly dissociates into fluoride, hydrogen and titanium ions upon dissolution in the environment, and only fluoride but not hydrogen and titanium ions will remain as such in solution, it can be assumed that toxicity (if any) will be driven by the fluoride anion. Therefore, full read-across of soil microbial toxicity data of potassium fluoride (CAS #7789-23-3) and other fluorides based upon a molecular weight conversion is justified (see below).

 

Potassium fluoride

The EU RAR reports NOEC values from 106 to 3000 mg/kg. The 63 day experiments were carried out in a micro-ecosystem containing poplar litter (30% o.m) and the isopod Porcellio scaber Latr. Nitrification was found to be the most sensitive endpoint investigated in the micro-ecosystem test.