Lithium hexafluorophosphate(1-)

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15-17 September 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD and EC guidelines and according to GLP principles.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Singular samples for possible analysis were taken from all test concentrations (0.1, 1, 10 and 100 mg/L) and the control.

Frequency: at t=0 h and t=48 h
Volume: 2 ml from the approximate centre of the test vessels
Storage: Samples were stored in a freezer until analysis.

At the end of the exposure period, the replicates were pooled at each concentration before sampling.

On the day of analysis the samples were defrosted at room temperature, diluted with 1% aqueous HNO3 to obtain concentrations within the calibration range and directly analysed.

Vehicle:

no

Details on test solutions:

The batch of LiPF6 tested was a white powder with a purity >99.9% and completely soluble in test medium at the concentrations tested.

Formulation started with weighing a surplus of test substance (6 grams) from the supplied test container in a glove-box in a nitrogen environment. This amount was transferred to the laboratory in a small bottle filled with nitrogen and kept in the dark for three days. During the actual formulation yellow light was applied. An amount of 100 mg was taken from the pre-weighed amount and dissolved in 1 litre of test medium. No special treatment other than careful mixing was necessary to completely dissolve the test substance in the test medium. The lower test concentrations were prepared by subsequent dilution. All final test solutions were clear and colourless.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia Magna
- Source: In-house laboratory culture with a known history. At least third generation, obtained by acyclical parthenogenesis under specified breeding conditions.
- Age at study initiation (mean and range, SD): < 24 hours, from parental daphnids of more than two weeks old.

- Method of breeding:
Start of each batch: With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 5 litres of medium in an all-glass culture vessel.
Maximum age of the cultures: 4 weeks
Renewal of the cultures: After 7 days of cultivation half of the medium twice a week.
Temperature of medium: 18-22°C
Feeding: Daily, a suspension of fresh water algae.
Medium: M7, as prescribed by Dr. Elendt-Schneider (Elendt, B.-P., 1990: Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus. Protoplasma 154, 25-33).

- Feeding during test: no feeding

ACCLIMATION
- Acclimation period: no

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

None.

Hardness:

180 mg/l expressed as CaCO3

Test temperature:

20 - 21.3 ºC

pH:

7.7 - 7.8

Dissolved oxygen:

8.9 - 9.1 mg/L

Salinity:

Not applicable

Nominal and measured concentrations:

Mean recoveries of the procedural recovery samples were 94% and 106%. Because the criterion that mean recoveries should be between 70% and 110% was met, the results for the test samples were accepted.
Analysis of the samples showed that measured concentrations were stable and in agreement with nominal throughout the test period (100-102%).

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 100 ml, all-glass
- Aeration: no aeration of the test solutions
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 0.10, 1.0 and 10 mg/l: 2; 100 mg/l: 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 5 daphnids per vessel containing 80 ml of test solution

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: 16 hours daily
- Light intensity:-


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10
- Justification for using less concentrations than requested by guideline:
- Range finding study
- Test concentrations: 0.1, 1.0, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study:

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Li

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Li

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Li

Basis for effect:

mobility

Details on results:

No immobility was observed in any of the concentrations tested.

Results with reference substance (positive control):

The actual responses in the reference test with K2Cr2O7 are within the ranges of the expected responses at the different concentrations. Hence, the sensitivity of this batch of D. magna was in agreement with the historical data collected at NOTOX.

The 24h-EC50 was 0.77 mg/l with a 95% confidence interval between 0.68 and 0.91 mg/l.

The 48h-EC50 was 0.62 mg/l with a 95% confidence interval between 0.53 and 0.77 mg/l.

Reported statistics and error estimates:

None.

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present study LiPF6 did not induce acute immobilisation of Daphnia magna at 100 mg/l after 48 hours of exposure (NOEC).

The 48h-EC50 exceeded 100 mg/l, the regulatory limit concentration.

Description of key information

GLP-compliant guideline study available to assess acute toxicity to invertebrates.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

Under the conditions of the present study LiPF6 did not induce acute immobilisation of Daphnia magna at 100 mg/l after 48 hours of exposure (NOEC). This result is fully compatible with the reported low acute toxicity of fluoride and lithium to freshwater invertebrates (five different Daphnia 48h EC50 values from 98 to 304 mg F-/l cited in WHO EHC 227, 2002. Lithium bromide Daphnia 48h EC50 110 mg/l, Japan MoE 2001).