Dilithium titanate

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:

Experimental start date 13 January 2020. Experimental completion date 31 January 2020.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study conducted following the method described in the Council Regulation (EC) No 440/2008, Method C.2 ‘Acute toxicity for Daphnia’ (2008) which is equivalent to OECD Guideline for Testing of Chemicals No. 202 'Daphnia sp., Acute Immobilisation Test' (adopted April 13, 2004).

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Test item : Lithium titanate
Chemical name : Lithium titanium oxide
CAS name : Lithium titanium oxide
CAS number : 12031-82-2
EC number : 234-759-6
Sample provided by : LANXESS Deutschland GmbH
Empirical formula : Li2TiO3
Molecular mass : 109.8 g/mol
Structural formula : --
Date of receipt : 2016-09-27
Expiry date : 2021-09-23
Purity : > 98 %
Water solubility : 0.000383 g/L

Analytical monitoring:

yes

Details on sampling:

All samples were diluted 1:1 with acetonitrile and were stored at -18 °C in a deep freezer in 50 mL Sarstedt tubes until analysis.
Examinated at test start (0h) and at test end (48h).

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS
- Stage and instar at study initiation: neonates
- Source: Strain of Bundesgesundheitsamt Berlin
- Feeding during test: no feeding during the exposure period

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES, INCLUDING CULTURING CONDITIONS:
A population of parthenogenetic females of synchronized age structure has been maintained for more than 20 years in the test facility under constant temperature conditions (20 +/- 2 °C) at a 16 : 8 hour light : dark photoperiod (light intensity: < 20 µE x m-2 x s-1). The culture water (so-called 'M4 medium') was partly renewed once a week. The Daphnia were exclusively fed unicellular green algae (Desmodesmus subspicatus) 'ad libitum'. Mortalities of parent Daphnia during the culture period were recorded daily. The neonates were separated from their parent Daphnia by filtration prior to the acute test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

14.6°dH (=262 mg/L CaCO3)

Test temperature:

18-22°C

pH:

8

Dissolved oxygen:

>3 mg/L

Nominal and measured concentrations:

Nominal concentration: 100 mg/L;

Measured concentrations: 0.015 mg/L after 0 hours and 0.011 mg/L after 48 hours

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL glass beaker covered with watch glass
- Type: closed
- Volume of solution: 50 mL
- Aeration: none
- Renewal rate of test solution (frequency/flow rate): none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
M4 Medium according to OECD 202 and EC Method C.2

OTHER TEST CONDITIONS
- Adjustment of pH: pH measured to be 9.1 after test item addition, adjusted to 8.0
- Photoperiod: 16h light / 8h dark
- Light intensity: < 20 µE x m-2 x s-1

EFFECT PARAMETERS MEASURED:
At test start (0h)
- Temperature: control (concentration 0 mg/L) - 20.6°C; concentration 100 mg/L - 20.8°C
- Dissolved Oxygen: control (concentration 0 mg/L) - 8.4 mg/L; concentration 100 mg/L - 8.6 mg/L
- pH: control (concentration 0 mg/L) - 8.1; concentration 100 mg/L - 8.0

At test end (48h)
- Temperature: control (concentration 0 mg/L) - 20.0°C; concentration 100 mg/L - 20.0°C
- Dissolved Oxygen: control (concentration 0 mg/L) - 8.8 mg/L; concentration 100 mg/L - 8.6 mg/L
- pH: control (concentration 0 mg/L) - 7.8; concentration 100 mg/L - 7.8

VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY
- Test concentrations: 1, 10, 100 mg/L
- Results used to determine the conditions for the definitive study: no effect was observed during the range finding test, so the main test was conducting with the limit concentration of 100 mg/L

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

behaviour

Remarks:

Observations were made on the swimming ability and the percentage immobilised.

Remarks on result:

other: Saturation concentration

Remarks:

Undissolved particles of the test item were removed by filtration using a folded filter with a pore size of 7-12 µm and an aseptic filter Sartobran sterile capsules with a pore size of 0.45 µm + 0.2 µm.

Details on results:

No toxic effects against Daphnia magna STRAUS were observed at a limit test concentration of 100 mg/L under exposure conditions.

Reported statistics and error estimates:

At the limit concentration of 100 mg/L no toxic effects against Daphnia magna STRAUS were observed at the end of the 48 hour study period, thus no statistical analysis was required to determine the EC 50 immobilisation percentages at 24-hour intervals.

Validity criteria fulfilled:

yes

Remarks:

The immobilisation and other abnormalities in the controls did not exceed 10 % by the end of the test. The dissolved oxygen concentration remained above 3 mg/L throughout the exposure period. The pH of exposure solutions did not change by more than ± 1.

Conclusions:

No toxic effects against Daphnia magna STRAUS were observed at a test item concentration of 100 mg/L (limit test) after 48 h of exposure, under the exposure conditions laid out in the EU method C.2 and OECD TG 202.

Executive summary:

The acute toxicity of Lithium titanate to Daphnia magna STRAUS was assessed under static conditions. The study was conducted in accordance with the EU Method C.2, which is equivalent to OECD Guideline for Testing of Chemicals No. 202.

The Daphnia were exposed to a limit test concentration of nominally 100 mg/L of Lithium titanate dissolved in dilution water. Observations were made on the swimming ability and the percentage immobilised. 

No toxic effects against Daphnia magna STRAUS were observed at a limit test concentration of 100 mg/L after 48 h of exposure. 

Description of key information

No toxic effects against Daphnia magna STRAUS were observed at a limit test concentration of 100 mg/L under exposure conditions.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

> 100 mg/L

Additional information

The EC50 value should be read as ">100 mg/L".