Lithium fluoride

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1997-06-13 to 1997-12-23

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples were analyzed for lithium in triplicate using a FLM-AAS method developed and validated by the FMC Corporation. Measured concentrations of lithium chloride were calculated by multiplying measured lithium concentrations by 14.427.

Vehicle:

no

Details on test solutions:

Test solutions were prepared by adding appropriate amounts of lithium chloride (0.56, 1.12, 2.25, 4.50 and 9.00 g) to 9 L volumes of dilution water. The A and B replicates were prepared separately. A control of only dilution water was maintained concurrently with the test solutions.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

Rainbow trout used for the test ranged from 24 to 30 mm standard length (mean and standard deviation = 27 +/- 1.6 mm) and from 0.13 to 0.27 g wet weight (mean and standard deviation = 0.2 +/- 0.05 g) as measured from the control fish at test termination. Loading was calculated to be 0.22 g of fish tissue per liter of test solution.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

No

Hardness:

c(CaCO3)= 56 mg/L

Test temperature:

11.9 - 13.4 °C

pH:

The pH of the test solutions was affected by the presence of lithium chloride (i.e., the pH increased as the test substance concentrations increased).
The pH values of all test solutions ranged from 7.5 to 8.7 at test initiation and from 7.0 to 7.5 for the remainder of the test.

Dissolved oxygen:

10.6 to 11.0 mg/L (98 - 102 % of saturation) at test initiation;
≥ 6.6 mg/L (≥ 61 % of saturation) for the remainder of the test

Nominal and measured concentrations:

Nominal concentrations: Control, 62.5, 125, 250, 500 and 1000 mg LiCl/L
Measured concentrations: 0.0, 59.4, 188, 249, 516 and 1021 mg LiCl/L

Details on test conditions:

Not applicable

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

158 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

LiCl

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 118 and 249 mg/L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

59.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

LiCl

Basis for effect:

mortality (fish)

Details on results:

The 96-hour LC50 was 158 mg/L (based upon mean measured concentrations) with 95 % confidence limits of 118 and 249 mg/L. The NOEC was 59.4 mg/L based on the lack of mortality at this, the lowest, test concentration.

Results with reference substance (positive control):

No reference substance control.

Reported statistics and error estimates:

The LC50 values were estimated by a computer program using the following statistical methods: moving average angle, probit, logit, and non-linear interpolation. Confidence limits for LC50 values determined by non-linear interpolation were calculated by binomial probability. The method selected for reporting the test results was determined by the characteristics of the data, i.e., the presence or absence of 0 % and 100 % mortality and the number of concentrations in which mortalities between 0 and 100 % occurred.

Validity criteria fulfilled:

yes

Conclusions:

The 96-hour LC50 for lithium chloride was 158 mg/L (based upon mean measured concentrations) with 95 % confidence limits of 118 and 249 mg/L. The NOEC for lithium chloride was 59.4 mg/L based on lack of mortality at the lowest test concentration measured.

Executive summary:

A static freshwater toxicity test was conducted to determine the acute toxicity of lithium chloride to rainbow trout, Oncorhynchus mykiss according to OECD Guideline 203. Mean measured concentrations of lithium chloride ranged from 59.4 to 1021 mg/L and from 94 to 103 % of nominal concentrations. All test solutions appeared clear and colourless and concentrations remained stable throughout the test. The pH of the test solutions was affected by the presence of lithium chloride (i.e. the pH increased as the test substance concentrations increased). The pH values of all test solutions ranged from 7.5 to 8.7 at test initiation and from 7.0 to 7.5 for the remainder of the test. Mortality of the rainbow trout exposed for 96 hours to lithium chloride ranged from 0 % at 59.4 mg/L to 100 % at test concentrations >= 249 mg/L. No mortality occurred in the dilution water control. The 96-hour LC50 was 158 mg/L with 95 % confidence limits of 118 and 249 mg/L. The slope of the concentration response curve could not be calculated using the binomial method. The NOEC was 59.4 mg/L based on lack of mortality at the lowest test concentration measured.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

according to guideline

Guideline:

other: U.S Environmental Protection Agency, 600/3-75-009: Method for Acute Toxicity Tests with Fish and Macroinvertebrates

Deviations:

not specified

GLP compliance:

no

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

Test fluoride solutions were prepared from sodium fluoride, geometrically increasing the concentration with an approximate factor of 1.6. A control and five different fluoride concentrations were used per bioassay. Fluoride bioassays were performed in duplicate. Fluoride concentrations were monitored daily using an Orion model 94-09 specific ion electrode.

Test organisms (species):

other: Salmo trutta and Oncorhynchus mykiss (reported as Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta)
- Source: Fry of rainbow trout and brown trout were obtained from Spanish ICONA trout hatchery.
- Age at study initiation: about two months

ACCLIMATION
- Acclimation period: 4 Days
- Type and amount of food: None
- Health during acclimation (any mortality observed): No fish died during the acclimatisation

Test type:

static

Water media type:

freshwater

Limit test:

no

Remarks on exposure duration:

from 96 h to 192 h (see section results and discussions)

Post exposure observation period:

No post exposure period

Hardness:

21.2 ± 2.55 ppm (Salmo trutta); 22.4 ± 1.79 ppm (Oncorhynchus mykiss)

Test temperature:

16.1 ± 0.13 °C (Salmo trutta); 15.3 ± 0.22 °C (Oncorhynchus mykiss)

pH:

7.63 ± 0.189 (Salmo trutta); 7.58 ± 0.179 (Oncorhynchus mykiss)

Dissolved oxygen:

10.1 ± 0.20 (Salmo trutta); 10.1 ± 0.28 (Oncorhynchus mykiss)

Salinity:

No data

Nominal and measured concentrations:

All effect concentrations were given in ppm. This value equals mg/L in aqueous solutions. The different concentration levels were measured but not indicated in the publication.

Details on test conditions:

Laboratory bioassays were performed in a glass aquaria each containing 20 L of dechlorinated tap water. Necessary water oxygenation and turbulence were produced by an air pump per aquarium. Natural photoperiod was utilised and water temperature was maintained by means of a cooling unit with thermostat. A control and five different fluoride concentration aquaria were used per bioassay. Fluoride bioassays were performed in duplicate. Each trout species was separately tested using ten fish per aquarium.

A variety of water parameters are given above. Further parameters tested were:
- Alkalinity: 32.2 ± 1.92 ppm (Salmo trutta); 37.5 ± 2.09 ppm (Oncorhynchus mykiss)
- Chloride: 10.8 ±0.43 ppm (Salmo trutta); 10.0 ± 1.22 ppm (Oncorhynchus mykiss)

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

164.5 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: based on fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Salmo trutta (95% CI: 161.2 - 114.0); p < 0.05

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

107.5 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: based on fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Oncorhynchus mykiss (95% CI: 138.0 - 83.7).

Duration:

120 h

Dose descriptor:

LC50

Effect conc.:

135.6 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: based on fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Salmo trutta (95% CI: 161.2-114.0); p < 0.05.

Duration:

120 h

Dose descriptor:

LC50

Effect conc.:

92.4 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: based on fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Oncorhynchus mykiss (95% CI: 116.0 - 73.6).

Duration:

144 h

Dose descriptor:

LC50

Effect conc.:

118.5 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: based on fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Salmo trutta (95% CI: 149.2-94.1); p < 0.05.

Duration:

144 h

Dose descriptor:

LC50

Effect conc.:

85.1 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: based on fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Oncorhynchus mykiss (95% CI: 106.5 - 68.0).

Duration:

168 h

Dose descriptor:

LC50

Effect conc.:

105.1 other: ppm

Nominal / measured:

meas. (not specified)

Conc. based on:

other: based on fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Salmo trutta (95% CI: 134.9-81.8); p < 0.05.

Duration:

168 h

Dose descriptor:

LC50

Effect conc.:

73.4 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: based on fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Oncorhynchus mykiss (95% CI: 96.4 - 55.9).

Duration:

192 h

Dose descriptor:

LC50

Effect conc.:

97.5 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: based on fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Salmo trutta (95% CI: 123.8-76.8); p < 0.05

Duration:

192 h

Dose descriptor:

LC50

Effect conc.:

64.1 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: based on fluoride ion (F-)

Basis for effect:

mobility

Remarks on result:

other: Oncorhynchus mykiss (95% CI: 82.2 - 50.0)

Results with reference substance (positive control):

Not applicable.

Reported statistics and error estimates:

The LC50 values at 96, 120, 144, 168 and 192 h, their 95% confidence limits and x² values were determined by the method of Litchfield and Wilcoxon, using mortalities and mean assay F- concentrations obtained in duplicate for each trout species.

Sublethal observations / clinical signs:

LC50 values for salmo trutta were significantly (p < 0.05) higher than those for Oncorhynchus mykiss to sodium fluoride for 96, 120, 144 and 192 hours. This indicates that Oncorhynchus mykiss is the more sensitive species to F- ions than Salmo trutta.

Validity criteria fulfilled:

not specified

Conclusions:

The LC50 values for salmo trutta were 164.5, 135.6, 118.5, 105.1 and 97.5 mg F/L after 96, 120, 144, 168 and 192 h respectively. The LC50 values for Oncorhynchus mykiss were 107.5, 92.4, 85.1, 73.4 and 64.1 mg F/L after 96, 120, 144, 168 and 192 h respectively.

Executive summary:

A static freshwater test with Salmo trutta and Oncorhynchus mykiss exposed to sodium fluoride was performed. Determined effect concentrations were expressed in terms of fluoride ions (F-) and based on measured concentrations. The LC50 values for salmo trutta after exposure to sodium fluoride were 164.5, 135.6, 118.5, 105.1 and 97.5 mg F/L after 96, 120, 144, 168 and 192 h respectively. The LC50 values for Oncorhynchus mykiss were 107.5, 92.4, 85.1, 73.4 and 64.1 mg F/L after 96, 120, 144, 168 and 192 h respectively. LC50 values for salmo trutta were significantly (p < 0.05) higher than those for Oncorhynchus mykiss to sodium fluoride for 96, 120, 144 and 192 hours. This indicates that Oncorhynchus mykiss is the more sensitive species to F- ions than Salmo trutta.

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

no guideline followed

Principles of method if other than guideline:

The review includes summaries of a number of studies, performed according to various guidelines.

GLP compliance:

not specified

Vehicle:

not specified

Test organisms (species):

other: various

Test type:

not specified

Water media type:

freshwater

Remarks on exposure duration:

48 and 96 hours

Hardness:

between 17 and 78 mg CaCO3/L (see details in section results and discussions)

Test temperature:

no data

pH:

no data

Dissolved oxygen:

no data

Salinity:

no data

Nominal and measured concentrations:

no data

Details on test conditions:

no data

Reference substance (positive control):

not specified

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

51 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Oncorhynchus mykiss; Hardness: 25 mg CaCO3/L (Janssen et al. 1989)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

107.5 mg/L

Nominal / measured:

nominal

Conc. based on:

other: based on fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Oncorhynchus mykiss; Hardness: 22 mgCaCO3/L (Camargo and Tarazona 1991)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

164.5 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

other: based on fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Salmo trutta; Hardness: 21 mgCaCO3/L (Camargo and Tarazona 1991)

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

299 mg/L

Nominal / measured:

nominal

Conc. based on:

other: fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Leuciscus melanotus; Hardness: 25 mg CaCo3/L (Juhnke and Ludemann 1978)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

340 mg/L

Nominal / measured:

nominal

Conc. based on:

other: fluoride ion (F-)

Basis for effect:

mortality (fish)

Remarks on result:

other: Gasterosteus aculeatus; Hardness: 78 mg CaCO3/L (Janssen et al. 1989)

Sublethal observations / clinical signs:

All reported tests with aquatic organisms were performed with NaF and the results were corrected for fluoride ion. Subsequently the effect concentrations were recalculated for the test item, lithium fluoride based on the molecular weight.

Validity criteria fulfilled:

not applicable

Conclusions:

The reported LC50 values for various fish species ranged from 51 - 340 mg F/L.

Executive summary:

The EU RAR reviews and summarizes the available data on short-term toxicity to fish. All reported tests were performed with NaF and the test results were corrected for fluoride ion (F-). Reported LC50 values for various fish species ranged from 51 to 340 mg F/L.

Description of key information

After 96 hours of exposure of Oncorhynchus mykiss to sodium fluoride an LC50 of 51 mg F-/L was determined. Based on the molecular weight, a recalculation for lithium fluoride was performed and revealed an LC50 of 69.64 mg LiF/L (EU-RAR 2001). This was the lowest determined LC50 value and is therefore considered as key value.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

69.64 mg/L

Additional information

A short-term toxicity study on fish with lithium fluoride is not available. Consequently, read-across was applied using characteristically similar compounds, lithium chloride and sodium fluoride. 

Read-across with sodium fluoride (Camargo & Tarazona 1991, Camargo 1991, EU RAR 2002) 
Effect concentrations of several short-term toxicity studies performed with sodium fluoride are available in the literature. Camargo (1991) and Camargo & Tarazona (1991) conducted a static freshwater test with Salmo trutta and Oncorhynchus mykiss exposed to sodium fluoride. Determined effect concentrations were expressed in terms of fluoride ions (F-) and based on measured concentrations. LC50 values for Salmo trutta were significantly (p < 0.05) higher than those for Oncorhynchus mykiss to sodium fluoride for 96, 120, 144 and 192 hours. This indicates that Oncorhynchus mykiss is the more sensitive species to F- ions than Salmo trutta. After an exposure duration of 96 hours, LC50 values for Salmo trutta and Oncorhynchus mykiss of 164.5 mg F/L and 107.5 mg F/L were determined. Based on the molecular weight, a recalculation for lithium fluoride was performed and revealed LC50 values (96h) for Salmo trutta and Oncorhynchus mykiss of 224.6 mg LiF/L and 146.8 mg LiF/L, respectively.

The EU-RAR (2002) reviews and summarizes the available effect concentrations of fluoride to various fish species. All reported tests were performed with NaF and the test results were corrected for fluoride ion (F-). Reported LC50 values for various fish species ranged from 51 to 340 mg F/L. The lowest LC50 value of 51 mg/L is based on a toxicity study with Oncorhynchus mykiss after an exposure duration of 96 hours. The recalculated 96-hour LC50 for lithium fluoride for Oncorhynchus mykiss is 69.64 mg LiF/L.

Read-across with lithium chloride (Toxikon 1997): 

A short-term toxicity study with Oncorhynchus mykiss exposed to lithium chloride was performed according to OECD guideline 203 (Toxikon 1997). Rainbow trout were exposed for 96 hours to the following nominal concentrations: 62.5, 125, 250, 500 and 1000 mg LiCl/L and a control group. Mean measured concentrations of lithium chloride ranged from 59.4 to 1021 mg/L and from 94 to 103 % of nominal concentrations. Based on the measured concentrations a 96-hour LC50 of 158 mg LiCl/L and a NOEC of 59.4 mg LiCl/L was determined. Based on the molecular weight, a recalculation for lithium fluoride was made and revealed an LC50 and NOEC of 96.69 and 36.35 mg LiF/L. 

Conclusion:

In this weight of evidence approach the effect concentrations of lithium and fluoride compounds were evaluated in different fish species. The results of the studies with the OECD guideline 203 compliant species Oncorhynchus mykiss after an exposure time of 96 hours were considered as the most reliable endpoint. The fish species showed LC50 values in the same range for lithium and fluoride, however, fish seemed to be more sensitive to fluoride compounds. Fluoride was considered as the more toxicological relevant moiety with respect to short-term toxicity to fish and the lowest 96-hour LC50 for Oncorhynchus mykiss of 69.64 mg LiF/L was considered as key value for chemical risk assessment.