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Environmental fate & pathways

Bioaccumulation: aquatic / sediment

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Dipotassium hexafluorotitanate will rapidly dissociate into fluoride, potassium and titanium ions upon dissolution in the environment. However, titanium ions will not remain in solution, only fluoride ions do. Therefore, full read-across to potassium fluoride (CAS #7789-23-3) and other fluorides based upon a molecular weight conversion is justified. Fluoride accumulates in aquatic organisms predominantly in the exoskeleton of crustacea and in the skeleton of fish; no accumulation was reported for edible tissue.Accordingly, it can be assumed that dipotassium hexafluorotitanate does not have a potential for bioaccumulation in aquatic tissues.

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Additional information

Dipotassium hexafluorotitanate

Dipotassium hexafluorotitanate is an inorganic substance which will rapidly dissociate into fluoride, potassium and titanium ions upon dissolution in the environment. However, titanium ions will not remain in solution, only fluoride ions do. The analysis of dissolved titanium levels in aquatic toxicity test solutions for algae, daphnia and fish according to OECD 201, 202 and 203 (Schlechtriem, 2013a, b; Teigeler, 2013) indicates that up to a loading of 100 mg/L dipotassium hexafluorotitanate, very low levels of titanium (often < 10% or even 5%) remain in solution at environmentally relevant pH while nearly all of the fluoride (often more than 95 %) could be recovered.

Thus, regarding the environmental fate and toxicity of dipotassium hexafluorotitanate, it can be assumed that toxicity (if any) will be driven by the fluoride anion. Therefore, full read-across to potassium fluoride (CAS #7789-23-3) and other fluorides based upon a molecular weight conversion is justified.

Potassium fluoride

In freshwater aquatic organisms it was found that the fluoride accumulates primarily in the exoskeleton of crustacea and in the bones of fish. In fish, the BCF value was between 53 -58 (d.w.) and <2 (w.w.). In crustacea, BCF value was <1 (d.w.). The highest reported BCF value for mollusca and aquatic macrophyta were 3.2 and 7.5 (w.w) respectively. In an experimental marine ecosystem with fish, crustaceans and plants, fluoride was found to accumulate in all species. The highest value, 149, was found in fish. BCF values for crustacea range from 27 to 62. Fluoride concentrations up to 30 mg F/kg were found in consumption fish. The limited data indicate that fluoride biomagnification in the aquatic environment is of little significance. Fluoride accumulates in aquatic organisms predominantly in the exoskeleton of crustacea and in the skeleton of fish; no accumulation was reported for edible tissue.