Bismuth hydroxide nitrate oxide

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:

26 April 2010 - 27 July 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP test according to OECD guidelines

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples from control and the test item concentration were taken at the start end the end of the exposure period and analysed to determine the actual test item concentrations in comparison to the nominally applied concentrations.
Before analysis, the samples were stored in a refrigerator in polyethylene bottles.

Vehicle:

no

Details on test solutions:

A stock solution was prepared by dissolving 205.6 mg of the test item (corresponds to 150 mg Bi at 73% Bismuth content) in 1500 mL of Medium M4 (nominal concentration 100 mg Bi/L). After agitation at 100 rpm on a horizontal laboratory shaker at ambient temperature in the dark for seven days,the stock solution was filtered through a glass fibre filter (pore size: 0.6 µm). The filtrate was used as the limit test item concentration. The filtrate of the stock solution was used as the limit test item concentration. Medium M4 was used as control for the test. The volume of stock solution was large enough to prepare the test concentration level and all analytical samples. The test solutions were filled into the test vessels and were placed into a temperature-controlled room for temperature adaptation.

Test organisms (species):

Daphnia magna

Details on test organisms:

Strain: STRAUS/clone 5
Breeder: ECT Oekotoxikologie GmbH since October 11, 2000
Medium: Medium M4
renewal of medium: 2 times per week
Age at start of test: less than 24 h
Temperature: 20 ± 2°C
Feed:TetraMin, Algae (Desmodesmus subspicatus), instant baker's yeast suspension
feeding frequency: 3 times per week

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

250 mg CaCO3/l

Test temperature:

20.3-20.5 °C

pH:

7.7-7.9

Dissolved oxygen:

8.0-8.7 mg/L

Nominal and measured concentrations:

nominal added concentration: control and 100% of water-accomodated fraction (100 mg Bi/L). Measured Bi concentrations were in all samples below detection limit (0.0375 mg Bi/L).

Details on test conditions:

Glass beakers (300 mL; height: 5.5 cm; diameter: 9 cm) covered by glass lids were used as test vessels. 150-170 mL test solution per vessel.
After temperature adaptation of the test solutions the daphnids were transferred into the test solutions by using an upside-down glass pipette. No feeding during the test. No aerationof test vessels.
16 hours light / 8 hours darkness. Light intensity: 419 to 565 lux
Number of replicates per test concentration: 6. 5 animals per vessel.
Effect parameter: immobility. Those animals not able to swim within 15 seconds after gentle agitation of the test vessel were considered to be immobile. Observations were made at 24 and 48h after the start of the study.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 137 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No immobilisation or behavioural abnormalities were observed in the control and the water-accommodated fraction at a loading rate of 100 mg Bismuth/L (137 mg test item/L).
The measured (dissolved) concentrations of Bismuth were below the limit of detection (LOD: 0.0375 mg Bi/L; 0.051 mg test item/L) in all samples.

Results with reference substance (positive control):

The reference test with potassium dichromate performed in may 2010 resulted in an 24h-EC50 of 0.66 mg/L. According to the OECD guideline 24h-EC50 guideline values should range between 0.6 and 2.1 mg/L. The toxicity of the reference item is within this range.

Reported statistics and error estimates:

No statistical method was used to evaluate the daphnid immobilities because no immobilities were observed during the test period in the control or the test item treatment.

Validity criteria fulfilled:

yes

Conclusions:

GLP test according to OECD guidelines. No effect was observed in a limit test with the water-accommodated fraction at a loading of 137 mg/L test item (100 mg Bi/L) and therefore the 48h-EC50 for immobilization of Daphnids is > 137 mg/L test item (100 mg Bi/L).

Executive summary:

A GLP test was conducted according to OECD guidelines. No effect was observed in a limit test with the water-accommodated fraction at a loading of 137 mg/L test item (100 mg Bi/L) and therefore the 48h-EC50 for immobilization of Daphnids is > 137 mg/L test item (100 mg Bi/L).

Description of key information

The 48h-EC50 for immobilization of Daphnids is > 137 mg/L test item.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

137 mg/L

Additional information

A GLP test was conducted according to OECD guidelines using bismuth subnitrate. No effect was observed in a limit test with the water-accommodated fraction at a loading of 137 mg/L test item (100 mg Bi/L) and therefore the 48h-EC50 for immobilization of Daphnids is > 137 mg/L test item (>100 mg Bi/L).