Bismuth hydroxide nitrate oxide

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:

10 May 2010- 21 May 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 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

Deviating from the study plan, the daily amount of food in the fish holding was not adjusted to 2% of fish fresh weight, but the fish in the holding tanks were fed with dry food (TetraMin®) and live Artemia nauplius larvae ad libitum.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples from test solutions were taken for analysis of actual test item concentrations in comparison to the nominal concentrations. Samples were both taken at start of the test in fresh test solution and at the end of the test. All samples were stored refrigerated in polyethylene bottles.

Vehicle:

no

Details on test solutions:

Reconstituted water was used for the control. A stock solution (water accommodated fraction, WAF) at a loading rate of nominal 137 mg test item/L (100 mg Bismuth/L) was prepared by dissolving 2.74 g of the test item in 20 L of reconstituted water. This stock solution was agitated for seven days by using a horizontal laboratory shaker at ambient temperature in the dark. The shaker was set to a frequency of 100 rpm to keep the test item in permanent suspension according to OECD (2001). After that, the stock solution was filtered (pore size 0.4 µm) using a glass fibre filter and stored for one day at room temperature in the dark. The filtrate was used to prepare the desired test item concentrations by dilution with reconstituted water.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

- Supplier: ECT Oekotoxikologie GmbH, Germany (own breed; since November 2009)
Holding conditions:
−Material of stock vessel: glass
−Amount of water per stock vessel: approximately 140 L
−Depth of water in the stock vessel: 40 cm
−Estimated number of fish kept as a stock per holding vessel (batch size): approx. 58
−Body weight range of the fish: 0.07 to 0.66 g (mean value: 0.285 g, assessed in a sample consisting of 10 fish)
−Standard length range of the fish: 2.1 to 3.0 cm (assessed in a sample consisting of 10 fish)
−Water: reconstituted water (see section 13.4)
−Renewal of water: once per week
−Temperature of water: min/max 23.5/25.1°C (during 14 days before start of exposure)
−Food: TetraMin®, Artemia nauplius larvae
−Amount of food: ad libitum
−Feeding frequency: daily ration fed in 3 portions on workdays
−Photoperiod: 12 h light / 12 h dark
−Light intensity: 100 - 1000 lx
−Adaptation period (>12 d): 21 d
−Mortalities during the period of 7 d before start of the test (<2%): 0%
−Food was withheld from the fish for one day prior to the start of exposure.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

177-184 mg CaCO3/l

Test temperature:

21.7-22.5°C

pH:

7.0-7.5

Dissolved oxygen:

8.3-9.2 mg/L

Nominal and measured concentrations:

nominal added concentrations: control, 1, 3, 10, 30 and 100% of water-accommodated fraction at 100 mg Bi/L.
Measured Bi concentrations were in all treatments below the detection limit (0.003 mg BI/L)

Details on test conditions:

-Reconstituted water according to OECD guideline No. 203 was used to dilute the test item and to keep the fish before and during the period of the test. Prior to use, the reconstituted water was diluted with deionised water (1:1; v/v), and supplemented with 1% of artificial seawater.
−Amount of test solution per test vessel: 10 L
−Depth of test solution in the test vessels: 13.5 cm
−Number of fish per test vessel: 7
−Fish loading: 0.2 g per L
−Renewal of test solution and control water during the test period: none
−Feeding: none
−Photoperiod: light/dark - 12 h/12 h
−Light intensity: 100 - 1000 lux; measured: 125 to 304 lux
−Temperature (min / max): 21.7 / 22.5°C (daily measurements); 21.8 / 22.7°C (online measurements in one test vessel)
−Aeration: permanent

-effect parameter measured: mortality of fish

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 137 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

A concentration-response relationship was not found during the 96-hour exposure period. No mortalities were found in the control and the test item concentrations up to the water-accommodated fraction (WAF) at a loading rate of 100 mg Bismuth/L (137 mg test item/L). The LC50 (96 h) was therefore determined to be higher than the highest tested concentration.

Behavioral or morphological differences in the treatments compared to the control fish were not apparent during the exposure period.

The measured concentrations of Bismuth were below the limit of detection (LOD: 0.003 mg Bi/L; 0.004 mg test item/L) in all treatments.

Reported statistics and error estimates:

No statistical method was used to evaluate the fish mortalities because no mortality was observed during the test period in the control or the test item treatments.

Validity criteria fulfilled:

yes

Conclusions:

GLP study executed according to the OECD 203 guideline and a water accommodated fraction approach. No mortalities were found in the control and the test item concentrations up to the water-accommodated fraction (WAF) at a loading rate of 137 mg test item/L (100 mg Bismuth/L). The LC50 (96 h) was therefore determined to be higher than the highest tested concentration.

Executive summary:

A GLP study was executed according to the OECD 203 guideline and a water accommodated fraction approach. No mortalities were found in the control and the test item concentrations up to the water-accommodated fraction (WAF) at a loading rate of 137 mg test item/L (100 mg Bismuth/L). The LC50 (96 h) was therefore determined to be higher than the highest tested concentration.

Description of key information

The LC50 (96 h) of bismuth subnitrate, is  > 137 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

137 mg/L

Additional information

A GLP study was executed according to the OECD 203 guideline and a water accommodated fraction approach using bismuth subnitrate.

No mortalities were found in the control and the test item concentrations up to the water-accommodated fraction (WAF) at a loading rate of 137 mg test item/L (100 mg Bismuth/L). The LC50 (96 h) was therefore determined to be higher than the highest tested concentration.