Tungsten disulphide

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:

2001-11-02 to 2002-02-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Adopted 1984-04-04

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 16031/01
- Purity test date: >98%

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

Stock Solution: The solution (100 mg/L tst item were weighed out) was prepared with dilution water one day prior to application.
Dispersion Treatment: The stock solution was stirred fr 24 h on a megnetic stirrer and filltrated with 0.45 um
Limit Concentration: Saturated solution (saturated concentration)

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS
- Strain/clone: Clone 5
- Origin: Institut fur Wasser-, Boden-und Lufthygiene ds Bundesundheitsamtes, Corrensplatz, 14195 Berlin, FRG


ACCLIMATION
- Acclimation period:
- Acclimation conditions (same as test or not):
- Type and amount of food: Mix of Scenedesmus subspicatus and Chlorella vulgaris
- Feeding frequency: five times weekly ad libitum

Test type:

static

Water media type:

freshwater

Limit test:

yes

Post exposure observation period:

Number of Dahpnia incapable of swimming after 24 and 48 hours after exposure

Hardness:

Total hardness of 160 to 180 mg CaCo3/L

Test temperature:

18-22 C, +/- 1C

pH:

7.78

Dissolved oxygen:

8.76 mg/L

Nominal and measured concentrations:

The mean measured concentration was 380 ug Tungsten/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers, 50 ml volume were used.
- Material, size, headspace, fill volume: volume of the study medium 20 ml
- No. of organisms per vessel: 5 for test and 10 for control
- No. of vessels per concentration (replicates): Four
- No. of vessels per control (replicates): Two

RANGE-FINDING STUDY
A preliminary range finding test was conducted under static conditions. 100 mg/L were weighed out, stirred 24 h and fitered with 0.45 before using. Three dilutions (1:1, 1:10, 1:100) of the stock solutions were carried out and used for the preliminary test.

Reference substance (positive control):

yes

Remarks:

Potassuim dichromate

Key result

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

> 380 µg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat. (dissolved fraction)

Remarks:

Tested saturation concentration

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

> 380 µg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat. (dissolved fraction)

Remarks:

Tested saturation concentration

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Remarks:

Confidence Interval

Effect conc.:

> 2.2 - < 2.6 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Reference Substance: Potassium dichromate

Validity criteria fulfilled:

yes

Remarks:

Values of the reference substance (potassium dichromate) and control group after the 24 hours were fulfilled: 24h-EC50 range of 1.0 t0 2,5 mg/L, pH-value did not vary by more than 1 unit, dissolved O2 >5.2 mg/L

Conclusions:

At the saturation concentration (380 ug of W/L) tungsten disulphide no biologically significant effect was determined.

Executive summary:

There is short-term toxicity to aquatic invertebrates data available for tungsten disulphide. In the acute immobilisation test withDaphnia magna(STRAUS) the effect of the saturated concentration as limit concentration of the test item tungsten disulphide was determined according to OECD Guideline 202/EEC Directive 92/69/EEC Method C.2. The test item was clearly dissolved throughout exposure in the tested limit concentration. The study was conducted under static conditions over a 48 hour period. 20 test organisms were exposed to the saturation concentration and control. Concentration control analysis was carried out and reported by an external GLP laboratory. Tungsten was determined via ICP-MS. 200 mL were sampled at the beginning and end of the test. The mean measure concentration was 380 ug/L (as dissolved tungsten). In the satuation concentration (380 ug/L) no biologically significant effect was determined.

Description of key information

There is short-term toxicity to aquatic invertebrates data available for tungsten disulphide. In the acute immobilisation test with Daphnia magna (STRAUS) the effect of the saturated concentration as limit concentration of the test item tungsten disulphide was determined according to OECD Guideline 202/EEC Directive 92/69/EEC Method C.2. The test item was clearly dissolved throughout exposure in the tested limit concentration. The study was conducted under static conditions over a 48 hour period. 20 test organisms were exposed to the saturation concentration and control. Concentration control analysis was carried out and reported by an external GLP laboratory. Tungsten was determined via ICP-MS. 200 mL were sampled at the beginning and end of the test. The mean measure concentration was 380 ug/L. In the saturation concentration (380 ug/L) no biologically significant effect was determined.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

380 µg/L