Lithium hexafluorophosphate(1-)

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation in aquatic species, other

Remarks:

Macrophytes, algae, fish

Type of information:

other: Due to its hydrolytic instability, the registered substance will not be present in surface waters. Evaluation of bioaccumulation potential must therefore be based on its hydrolysis products. This information source reports lithium bioaccumulation data.

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Review (primarily concerned with short-lived P isotopes, but including data on measured levels of stable P (from phosphate) in river water and various fish species) published in a peer-reviewed journal

Justification for type of information:

Part of weight-of-evidence approach adapting the information requirements of Annex IX 9.3.2 under REACH in accordance with Annex XI Section 1.2. Following rapid hydrolysis of LiPF6 on contact with water, HF and subsequently the ionised hydrolysis products F-, Li+ and PO4- are present in solution. In accordance with section 2 of REACH Annex XI, bioaccumulation testing of LiPF6 is not technically possible due to its high reactivity and instability: further, in accordance with REACH Annex XI section 1.2 testing is not scientifically necessary since existing information is available to assess bioaccumulative properties of the dissolved hydrolysis products.

Principles of method if other than guideline:

Review of published literature on levels of stable P and 32P in river waters aquatic organisms of different trophic levels.

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Phosphate (as PO4(3+) is a known hydrolysis product formed from LiPF6 on contact with water

Test organisms (species):

other: various

Details on test organisms:

Macrophytes, algae, fish

Remarks on result:

other: Not determined

Remarks:

See "Any other information on results" section

Details on results:

Cited stable P concentrations in aquatic organisms (g/kg dry weight, whole-body):
- macrophytes, 2.0-8.4
- algae, 0.5-33
- fish (temperate species), 21.1-42.8.
The authors cite a fresh weight/dry weight ratio of 3 which can be used to convert these values into g/kg fresh weight

Cited stable P concentrations in river waters:
- English rivers draining to the North Sea, mid- to late-1990s, 0.06-1.8 mg/l
- lowland rivers among these, 0.14-1.8 mg/l
- UK EA water quality target for lowland rivers on alluvial or clay catchment, 0.10mg/l annual average
- dissolved P (calculated from measured phosphate levels) in river Cam, average 2001-2005 at two sites 0.49 mg/l.

Concentration ratios (CR values) calculable from these figures (after multiplying x3 for dw->fw conversion):
- fish (temperate species), 35,167-2,140,000
- macrophytes, 3,300-420,000
- algae, 834-1650.

Separately, a reported geometric mean concentration of stable P in fish muscle is cited. This value, 2.2 g/kg fresh weight, corresponds to a CR range of 1,222-36,666.

However, assimilation of P by fish from food is believed to be much greater than that from water: an estimate that intake of stable P from food is approximately 40,000 times greater than that from water is cited.

The reported CR values suggest accumulation of phosphorus within the studies organisms, but for fish (which showed the highest CR values) it is suggested that this is mainly ingested in food and not accumulated from the surrounding waters.

Conclusions:

Phosphorus and phosphate is essential to life and endogenous levels are homeostatically controlled. Reported concentrations of phosphorus (stable 31P, typically available as phosphate) in fish, algae and aquatic macrophytes are higher than those typical in surface waters, but uptake in fish may be primarily via ingestion of food.

Reference 2

Endpoint:

bioaccumulation in aquatic species, other

Type of information:

other: Due to its hydrolytic instability, the registered substance will not be present in surface waters. Evaluation of bioaccumulation potential must therefore be based on its hydrolysis products.

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: EC expert review, including assessment of environmental impact.

Justification for type of information:

Part of weight-of-evidence approach adapting the information requirements of Annex IX 9.3.2 under REACH in accordance with Annex XI Section 1.2. Following rapid hydrolysis of LiPF6 on contact with water, HF and subsequently the ionised hydrolysis products F-, Li+ and PO4- are present in solution. In accordance with section 2 of REACH Annex XI, bioaccumulation testing of LiPF6 is not technically possible due to its high reactivity and instability: further, in accordance with REACH Annex XI section 1.2 testing is not scientifically necessary since existing information is available to assess bioaccumulative properties of the dissolved hydrolysis products.

Principles of method if other than guideline:

Detailed expert review of environmental and health impact of HF

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Fluoride (F-) ions are a known hydrolysis product formed from LiPF6 on contact with water.

HF properties listed in the cited data source:
MP -83C, BP 19.5C at 1013 hPa
Water miscible
Low Kow -1.4

Test organisms (species):

other: fish, crustaceans, molluscs, aquatic macrophyta

Details on test organisms:

Freshwater: fish, crustaceans, molluscs, aquatic macrophyta.
Seawater: fish, crustaceans, plants

Route of exposure:

aqueous

Details on test conditions:

It is noted that in freshwater above pH 5, the principal chemical form present is free F- ion. At lower pH, the presence of non-dissociated HF and HF2- is increased.
In seawater, free F- and MgF+ are the major forms present

Details on estimation of bioconcentration:

BCF values (ww and/or dw) only cited

Type:

other: Freshwater fish BCF

Value:

>= 53 - <= 58 dimensionless

Basis:

other: whole body d.w. (BCF <2 based on wet weight)

Calculation basis:

other: Based on fluoride

Remarks on result:

other: Accumulation occurs in bones, not in edible tissues

Type:

other: Freshwater crustaceans BCF

Value:

< 1 dimensionless

Basis:

whole body d.w.

Calculation basis:

other: Based on fluoride

Remarks on result:

other: Accumulation occurs in exoskeleton

Type:

other: Marine fish BCF

Value:

149 dimensionless

Calculation basis:

other: based on fluoride

Remarks on result:

other: Up to 30 mg fluoride/kg reported in other marine fish used for food

Type:

other: Marine crustaceans

Value:

>= 27 - <= 62 dimensionless

Calculation basis:

other: based on fluoride

Remarks on result:

other: Accumulation also seen in marine plants

Type:

other: BCF in freshwater mollusca and macrophytes

Value:

>= 3.2 - <= 7.5 dimensionless

Basis:

whole body w.w.

Calculation basis:

other: based on fluoride

Reference 3

Endpoint:

bioaccumulation in aquatic species, other

Remarks:

review of bioaccumulation information

Type of information:

other: Due to its hydrolytic instability, the registered substance will not be present in surface waters. Evaluation of bioaccumulation potential must therefore be based on its hydrolysis products. This information source is an expert review.

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Information cited in a lithium (toxicity to humans and the environment) literature review published in a peer-reviewed journal, but lacking detail for the specific endpoint of bioaccumulation from surface waters

Justification for type of information:

Part of weight-of-evidence approach adapting the information requirements of Annex IX 9.3.2 under REACH in accordance with Annex XI Section 1.2. Following rapid hydrolysis of LiPF6 on contact with water, HF and subsequently the ionised hydrolysis products F-, Li+ and PO4- are present in solution. In accordance with section 2 of REACH Annex XI, bioaccumulation testing of LiPF6 is not technically possible due to its high reactivity and instability: further, in accordance with REACH Annex XI section 1.2 testing is not scientifically necessary since existing information is available to assess bioaccumulative properties of the dissolved hydrolysis products.

Principles of method if other than guideline:

Wide-ranging review including information on human therapeutic administration and animal studies using lithium carbonate plus dietary lithium intake, as well information on environmental origin and distribution of lithium.

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Lithium ions are a known hydrolysis product, formed from LiPF6 on contact with water

Remarks on result:

other: not determined

Remarks:

See "Any other information on results" section

Authors cite human and animal toxicokinetic information plus, for the aquatic environment, a prediction of non-bioaccumulation based on a low affinity for particles, then conclude "lithium is not expected to bioaccumulate and its human and environmental toxicity are low"

Conclusions:

Authors cite human and animal toxicokinetic information plus, for the aquatic environment, a prediction of non-bioaccumulation based on a low affinity for particles, then conclude "lithium is not expected to bioaccumulate and its human and environmental toxicity are low"

Reference 4

Endpoint:

bioaccumulation in aquatic species, other

Remarks:

>30 different marine species (including mammals, fish, crustaceans and other types)

Type of information:

other: Due to its hydrolytic instability, the registered substance will not be present in surface waters. Evaluation of bioaccumulation potential must therefore be based on its hydrolysis products. This information source reports lithium bioaccumulation data.

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Paper published in a peer-reviewed journal, reporting analysis of lithium content in 37 different marine species (including mammals, fish, crustaceans and other types) collected from offshore European and Japanese locations. Lacking in some experimental details, such that BCF values cannot be calculated.

Justification for type of information:

Part of weight-of-evidence approach adapting the information requirements of Annex IX 9.3.2 under REACH in accordance with Annex XI Section 1.2. Following rapid hydrolysis of LiPF6 on contact with water, HF and subsequently the ionised hydrolysis products F-, Li+ and PO4- are present in solution. In accordance with section 2 of REACH Annex XI, bioaccumulation testing of LiPF6 is not technically possible due to its high reactivity and instability: further, in accordance with REACH Annex XI section 1.2 testing is not scientifically necessary since existing information is available to assess bioaccumulative properties of the dissolved hydrolysis products.

Principles of method if other than guideline:

Retention or accumulation of lithium in samples collected from >30 different marine species (including mammals, fish, crustaceans and other types) collected from offshore European, American and Japanese locations was investigated using a sensitive secondary ion mass spectrometry method of analysis.

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Lithium ions are a known hydrolysis product of the reaction of LiPF6 with water

Test organisms (species):

other: >30 different species

Details on test organisms:

Blue and common dolphins. 5 different marine fish species. 14 marine crustacean species. 14 marine mollusc species. 1 marine annelid species

Route of exposure:

other: environmental exposure in seawater

Water / sediment media type:

natural water: marine

Remarks on result:

other: Not determined

Remarks:

See "Any other information on results" section

Details on results:

Among dolphins and fish, the highest lithium concentrations were found in samples of muscle tissue (that of the flounder showing the greatest value) while in crustaceans of commercial importance little or no lithium retention was seen in edible tissues. No measurements of seawater Li+ levels are presented, but a report of 173 µgLi/l in ocean surface waters is cited; no BCF values are calculable. Even the findings in dolphins and fish do not provide evidence of marked bioaccumulation.

Although the results indicate some retention, and possible limited bioaccumulation, of lithium in the studied fish and dolphins, no specific BCF values are calculated and the reported data do not provide evidence of marked bioaccumulation.

Reference 5

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

other: Due to its hydrolytic instability, the registered substance will not be present in surface waters. Evaluation of bioaccumulation potential must therefore be based on its hydrolysis products. This information source is a governmental study summary.

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Robust summary of fish study performed under a governmental HPV programme, but lacking in some experimental detail (original study report not translated).

Justification for type of information:

Part of weight-of-evidence approach adapting the information requirements of Annex IX 9.3.2 under REACH in accordance with Annex XI Section 1.2. Following rapid hydrolysis of LiPF6 on contact with water, HF and subsequently the ionised hydrolysis products F-, Li+ and PO4- are present in solution. In accordance with section 2 of REACH Annex XI, bioaccumulation testing of LiPF6 is not technically possible due to its high reactivity and instability: further, in accordance with REACH Annex XI section 1.2 testing is not scientifically necessary since existing information is available to assess bioaccumulative properties of the dissolved hydrolysis products.

Principles of method if other than guideline:

28-day fish bioaccumulation study with two exposure concentrations

GLP compliance:

not specified

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Lithium bromide, where the dissociated Li+ ion is comparable to that produced by hydrolysis of LiPF6

Details on sampling:

Data not available

Vehicle:

not specified

Details on preparation of test solutions, spiked fish food or sediment:

Data not available

Test organisms (species):

Cyprinus carpio

Route of exposure:

aqueous

Nominal and measured concentrations:

Nominal concentrations 3 and 0.3 mg/l

Lipid content:

1.67 %

Time point:

start of exposure

Lipid content:

2.03 %

Time point:

end of exposure

Type:

BCF

Value:

< 4.3 dimensionless

Basis:

not specified

Calculation basis:

steady state

Remarks on result:

other: based on lithium

Remarks:

Conc.in environment / dose:3 mg/l

Type:

BCF

Value:

< 31 dimensionless

Basis:

not specified

Calculation basis:

steady state

Remarks on result:

other: Based on lithium

Remarks:

Conc.in environment / dose:0.3 mg/l

Description of key information

Following rapid hydrolysis of LiPF6 on contact with water, HF and subsequently the ionised hydrolysis products F-, Li+ and PO4- are present in solution. In accordance with section 2 of REACH Annex XI, bioaccumulation testing of LiPF6 is not technically possible due to its high reactivity and instability: further, in accordance with REACH Annex XI section 1.2 testing is not scientifically necessary since existing information is available to assess bioaccumulative properties of the dissolved hydrolysis products. Detailed weight-of-evidence assessment is summarised under additional information section below.

Additional information

Bioaccumulation

Following rapid hydrolysis of LiPF6 on contact with water, HF and subsequently the ionised hydrolysis products F-, Li+ and PO4- are present in solution. In accordance with section 2 of REACH Annex XI, bioaccumulation testing of LiPF6 is not technically possible due to its high reactivity and instability: further, in accordance with REACH Annex XI section 1.2 testing is not scientifically necessary since existing information is available to assess bioaccumulative properties of the dissolved hydrolysis products.

 

HF

In fresh or marine waters, HF will principally be present in the form of fluoride ion. For this reason, test data relevant to soluble inorganic fluorides can be used to evaluate the bioaccumulative potential of HF. 

 

Fluoride

In freshwater, fluoride BCF values (based on dry weight) of 53 – 58 and <1 have been reported for fish and crustaceans respectively; a BCF value (based on wet weight) of 3.2 has been reported for molluscs (and 7.5 in aquatic macrophytes). As in mammals, fluoride is retained in fish bones and the exoskeleton of crustaceans: no such accumulation has been reported in edible fish tissue (HF: EU Risk Assessment Report, 2001).

 

Lithium

In a 28-day test, carp exposed to lithium bromide showed or no indication of lithium bioaccumulation. BCF values at two test concentrations being <31 (Japan NITE, 2001). A review of lithium toxicity concluded that lithium is not expected to bioaccumulate (Aral and Vecchio-Sadus, 2008) and in man and animals most of an absorbed dose of lithium is rapidly removed from the circulating blood (Hunter, 1998) and excreted via the kidneys (Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals 131, 2002). There is some evidence of retention or accumulation of lithium in certain marine species: analysis of the lithium content of >30 different marine species (including mammals, fish, crustaceans and other types) collected from offshore European, American and Japanese locations using a sensitive secondary ion mass spectrometry method found lithium in most cases (Chassard-Boucheau et al, 1984). The investigators reported measured ion intensity ratios (7Li/40Ca) recorded in processed samples from various tissues and/or organs. Among dolphins and fish, the highest lithium concentrations were found in samples of muscle tissue (that of the flounder showing the greatest value) while in crustaceans of commercial importance little or no lithium retention was seen in edible tissues. No measurements of seawater Li+ levels are presented, although a report of 173 µgLi/l in ocean surface waters is cited and no BCF values are calculable. Even the findings in dolphins and fish do not provide evidence of marked bioaccumulation.

 

Phosphate/phosphorus

 Uptake of phosphorus present in water as dissolved phosphate is believed to be a minor contributor to accumulated phosphorus in fish, with phosphorus intake in food being estimated to be some 40,000 times greater (Smith, Bowes and Cailes, 2011). An overall Concentration Factor for the stable form of phosphorus in the edible portion (muscle) of larger freshwater fish can be calculated from the data of these authors to have an approximate range of 1,222-36,666, but most of the accumulated phosphorus is likely to have been taken up from feeding and not by absorption from water.