Lithium bis[ethanedioato(2-)-κO1,κO2]difluorophosphate(1-)

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2016-01-11 to 2016-02-23

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

Specific details on test material used for the study:

Batch No.: 150209
Purity: 97.7 wt%

Analytical monitoring:

yes

Details on sampling:

- Concentrations: a nominal concentration of 102 mg/L test group and a blank control containing no test substance
- Sampling time: samples were taken at 0 h, 96 h and 24 h, 48 h, 72 h (before and after the renewal) after the start of the test.

Vehicle:

no

Details on test solutions:

- Preparation of test solution: 0.510 g of test substance was dissolved in a flask with some amount of test water and transferred into a 5L-jar and diluted with test water to 5000 mL to obtain the nominal concentration of 102 mg/L solution (99. 7 mg/L active constituent calculated by the 97.7% purity of test substance). The pH of test solution ranged from 3.32 to 3.41 and was adjusted to 7.6-8.0 by NaOH solution. Then the solution was stirred with a magnetic stirrer for about 24 hours to make sure test substance dissolved and used in the test directly.
- Controls: A blank control (test water without test substance)

Test organisms (species):

other: Rare Minnow (Gobiocypris rarus)

Details on test organisms:

TEST ORGANISM
- Reason for selection of species: The test species is recommended by "The Guidelines for the Testing of Chemicals".
- Supplier: Institute of Hydrobiology, Chinese Academy of Sciences.
- Total number of test fish: 14

ACCLIMATION
- Acclimated for 40 days under the domestication conditions:
Water: dechlorinated tap water
Temperature: 23±2 °C
Photoperiod: 14 h light / 10 h dark
- Acclimated for 42 days under the domestication conditions:
Water: 10% dechlorinated tap water diluted with deionized water
Temperature: 23±2 °C
Photoperiod: 14 h light / 10 h dark
- Dissolved oxygen concentration: above 80% of the air saturation value
- Feeding frequency: at least 3 times per week until 24 hours before the start of the test

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

19.5 mg/L (CaCO3) (duiled 10% dechorinated tap water with deionized water)
232 mg/L (CaCO3) (dechorinated tap water)

Test temperature:

21.0-23.0 °C

pH:

7.36-7.98

Dissolved oxygen:

not less than 60 % of the air saturation value.

Nominal and measured concentrations:

Norminal concentration: 102 mg/L

Details on test conditions:

TEST SYSTEM
- Groups: test group and a blank group containing no test substance
- Number of fish: 7 fish / test group, 14 fish in total
- Replicate: no replicates
- Volume of test solution: 5 L / test vessel
- Loading of test fish: 7 fish / test vessel, 0.232 g fish / L
- Feeding: no feeding

OTHER TEST CONDITIONS
- Adjustment of pH: The test was performed without adjustment of pH and the pH was in the range of 7.36 to 7.98 during the test.
- Aeration: no aeration
- Photoperiod: 14 h light / 10 h darkness

Range finding study
- Test concentrations: the nominal loading rate of 9.6 mg/L WAF, 31.2 mg/L WAF, 100 mg/L WAF (Water-accommodated fraction)
- Results used to determine the conditions for the definitive study: The 96h cumulative mortalities of test fish were all 0% of the blank control and the test groups.

Reference substance (positive control):

yes

Remarks:

K2Cr2O7

Key result

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

102 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 102 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

> 102 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Mortality: At the end of the test, the cumulative mortalities of blank control and the 102 mg/L test group were both 0%.
- Observations on body length and weight: The average and standard deviation of test fish's body weight and total length were respectively 0.166 g ± 0.023 g and 30.43 mm ± 1. 54 mm.
- Abnormal responses: No abnormal responses were observed in blank control and the 102 mg/L test group.
- Observation of test solutions: The blank control was observed to be clear and colorless during the test period. A small amount of precipitation was observed in the 102 mg/L test group during the test period.

Results with reference substance (positive control):

The acute toxicity test of K2Cr2O7 with Rare Minnow (Gobiocypris rarus) showed that the 24 h-LC50 of the reference substance (K2Cr2O7) was 326 mg/L to Rare Minnow (Gobiocypris rarus) and the 95% confidence limits ranged from 276 mg/L to 386 mg/L.

Sublethal observations / clinical signs:

The measured concentrations of Lithium:

The measured concentrations of Lithium in blank control were lower than the limit of detection (LOD= 0.00104 mg/L) at 0 h, 96 h and 24 h, 48 h, 72 h (before and after the renewal) after the start of the test. The measured concentrations of Lithium in the 102 mg/L test group ranged from 2.42 mg/L to 2.981 mg/L at the start of the exposure and after the renewal in new solutions (88%-109% of the nominal concentration of Lithium). And the measured concentrations ranged from 2.49 mg/L to 2.83 mg/L before the renewal and at the end of the exposure in old solutions (91 %-103 % of the nominal concentration of Lithium). The measured concentrations of Lithium could be maintained within ±20% of the nominal concentration of Lithium at 24 h intervals.

The measured concentrations of oxalic ion:

The measured concentrations of oxalic ion in blank control were 0.039 mg/L (0 h new solution) and 0.018 mg/L (24 h old solution). The measured concentrations of oxalic ion in the 102 mg/L test group ranged from 33.2 mg/L to 38.0 mg/L at the start of the exposure and after the renewal in new solutions (96%-109% of the nominal concentration of oxalic ion). And the measured concentrations ranged from 21.4 mg/L to 34.8 mg/L before the renewal and at the end of the exposure in old solutions (61%-100% of the nominal concentration of oxalic ion). The measured concentrations of oxalic ion could not always be maintained within ±20% of the nominal concentration of oxalic ion at 24 h intervals.

Validity criteria fulfilled:

yes

Conclusions:

Based on the nominal concentration, the median lethal concentration (96 h LC50) and the lowest concentration causing 100% mortality (96 h LC100) were more than 102 mg/L, and the highest concentration causing 0% mortality (96 h LC0) was 102 mg/L.

Executive summary:

A determination of the acute toxicity to fish of the substance was conducted in accordance with OECD Guideline 203, and in compliance with GLP.

Groups of 7 Rare Minnow (Gobiocypris rarus)were exposed to 0 (control group),102 mg/L (a nominal concentration) the substance in 10% dechlorinated tap water for 96 h.

At the end of the test, the cumulative mortalities of blank control and the 102 mg/L test group were both 0%. No abnormal responses were observed in blank control and the 102 mg/L test group. The body weight and total length of 7 test fish in the blank control were measured when the test was finished. The average and standard deviation of test fish's body weight and total length were respectively 0.166 g ± 0.023 g and 30.43 mm ± 1.54 mm. The blank control was observed to be clear and colorless during the test period. A small amount of precipitation was observed in the 102 mg/L test group during the test period.

The measured concentrations of Lithium in blank control were lower than the limit of detection at 0 h, 96 h and 24 h, 48h, 72h (before and after the renewal) after the start of the test. The measured concentrations of Lithium in the 102 mg/L test group ranged from 2.42 mg/L to 2.981 mg/L at the start of the exposure and after the renewal in new solutions. The measured concentrations of oxalic ion in blank control were 0.039 mg/L (0 h new solution) and 0.018 mg/L (24 h old solution). The measured concentrations of oxalic ion in the 102 mg/L test group ranged from 33.2 mg/L to 38.0 mg/L at the start of the exposure and after the renewal in new solutions.

Based on the nominal concentration, the median lethal concentration (96 h LC50) and the lowest concentration causing 100% mortality (96 h LC100) were more than 102 mg/L, and the highest concentration causing 0% mortality (96 h LC0) was 102 mg/L.

Description of key information

Based on the nominal concentration, the median lethal concentration (96 h LC50) and the lowest concentration causing 100% mortality (96 h LC100) were more than 102 mg/L, and the highest concentration causing 0% mortality (96 h LC0) was 102 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

102 mg/L

Additional information

A determination of the acute toxicity to fish of the substance was conducted in accordance with OECD Guideline 203, and in compliance with GLP.

Groups of 7 Rare Minnow (Gobiocypris rarus) were exposed to 0 (control group), 102 mg/L (a nominal concentration) the substance in 10% dechlorinated tap water for 96 h.

At the end of the test, the cumulative mortalities of blank control and the 102 mg/L test group were both 0%. No abnormal responses were observed in blank control and the 102 mg/L test group. The body weight and total length of 7 test fish in the blank control were measured when the test was finished. The average and standard deviation of test fish's body weight and total length were respectively 0.166 g ± 0.023 g and 30.43 mm ± 1.54 mm. The blank control was observed to be clear and colorless during the test period. A small amount of precipitation was observed in the 102 mg/L test group during the test period.

The measured concentrations of Lithium in blank control were lower than the limit of detection at 0 h, 96 h and 24 h, 48h, 72h (before and after the renewal) after the start of the test. The measured concentrations of Lithium in the 102 mg/L test group ranged from 2.42 mg/L to 2.981 mg/L at the start of the exposure and after the renewal in new solutions. The measured concentrations of oxalic ion in blank control were 0.039 mg/L (0 h new solution) and 0.018 mg/L (24 h old solution). The measured concentrations of oxalic ion in the 102 mg/L test group ranged from 33.2 mg/L to 38.0 mg/L at the start of the exposure and after the renewal in new solutions.

Based on the nominal concentration, the median lethal concentration (96 h LC50) and the lowest concentration causing 100% mortality (96 h LC100) were more than 102 mg/L, and the highest concentration causing 0% mortality (96 h LC0) was 102 mg/L.