Dihydrogen hexafluorotitanate(2-)

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation in aquatic species, other

Type of information:

other: review

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Various studies summarised in EU RAR and Dutch ICD

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

The RAR summarises the results of a number of studies

GLP compliance:

not specified

Radiolabelling:

no

Route of exposure:

aqueous

Type:

BCF

Value:

>= 53 - <= 58 dimensionless

Basis:

whole body d.w.

Remarks on result:

other: Freshwater Fish -Sloof et al (1988)

Type:

BCF

Value:

< 2 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: Freshwater Fish - Sloof et al (1988)

Type:

BCF

Value:

3.2 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: Freshwater mollusca- Chaisemartin

Type:

BCF

Value:

7.5 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: Freshwater Aquatic macrophyta - Chaisemartin

Type:

BCF

Value:

>= 27 - <= 62 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: Seawater Crustacea - Hemens and Warwick (1972)

Type:

BCF

Value:

30 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: Seawater Fish - Sloof et al (1988)

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 tissues.

Conclusions:

In freshwater aquatic organisms it was found that the fluoride accumulates primarily in the exoskeleton of crustacea and in the bones of fish. In an experimental marine ecosystem with fish, crustaceans and plants, fluoride was found to accumulate in all species.

Executive summary:

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, F was found to accumulate in all species. The highest value, 149, was found in fish. BCF values for crustacea range from 27 to 62 (Hemens and Warwick, 1972). Fluoride concentrations up to 30 mg F/kg were found in consumption fish (Slooff et al, 1988). 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

Reference 2

Endpoint:

bioaccumulation in aquatic species, other

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
Dihydrogen hexafluorotitanate is an inorganic substance which will rapidly dissociate into fluoride, hydrogen and titanium ions upon dissolution in the environment. However, hydrogen and titanium ions do not remain as such in solution, only fluoride ions do. The approach follows scenario 1 of the RAAF (ECHA 2017).

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Source
fluoride salts (various)
Target
Dihydrogen hexafluorotitanate (CAS 17439-11-1)

3. ANALOGUE APPROACH JUSTIFICATION
The hydrogen ion attaches to a hydroxide ion to form a water molecule. 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 dihydrogen 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.

4. DATA MATRIX
see attached read-across statement in section 13.2

Reason / purpose for cross-reference:

read-across source

Type:

BCF

Value:

>= 53 - <= 58 dimensionless

Basis:

whole body d.w.

Remarks on result:

other: Freshwater Fish -Sloof et al (1988)

Type:

BCF

Value:

< 2 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: Freshwater Fish - Sloof et al (1988)

Type:

BCF

Value:

3.2 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: Freshwater mollusca- Chaisemartin

Type:

BCF

Value:

7.5 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: Freshwater Aquatic macrophyta - Chaisemartin

Type:

BCF

Value:

>= 27 - <= 62 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: Seawater Crustacea - Hemens and Warwick (1972)

Type:

BCF

Value:

30 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: Seawater Fish - Sloof et al (1988)

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 tissues.

Conclusions:

In freshwater aquatic organisms it was found that the fluoride accumulates primarily in the exoskeleton of crustacea and in the bones of fish. In an experimental marine ecosystem with fish, crustaceans and plants, fluoride was found to accumulate in all species.

Executive summary:

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, F was found to accumulate in all species. The highest value, 149, was found in fish. BCF values for crustacea range from 27 to 62 (Hemens and Warwick, 1972). Fluoride concentrations up to 30 mg F/kg were found in consumption fish (Slooff et al, 1988). 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.

Description of key information

Dihydrogen hexafluorotitanate will rapidly dissociate into fluoride, hydrogen and titanium ions upon dissolution in the environment. However, hydrogen and titanium ions will not remain as such 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 dihydrogen hexafluorotitanate does not have a potential for bioaccumulation in aquatic tissues.

Additional information

Dihydrogen hexafluorotitanate

Dihydrogen hexafluorotitanate is an inorganic substance which will rapidly dissociate into fluoride, hydrogen and titanium ions upon dissolution in the environment. However, hydrogen and titanium ions will not remain as such in solution, only fluoride ions do.The hydrogen ion attaches to a hydroxide ion to form a water molecule.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 dihydrogen 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.