Niobium oxide

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2003-02-19

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Remarks:

Concentration analysis was carried out and reported by the sponsor under NON-GLP conditions.

Details on sampling:

- Concentrations: saturated solution
- Sampling method: 100 mL each of the saturated concentration and control were sampled at the beginning and end of the test.
- Sample storage conditions before analysis: The samples were stored in PE bottles at 4 - 8°C until shipping.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test item was diluted in water. A saturated solution was tested, prepared with 100 mg/L. The test solution (4 L) was shaken for 24 h at 20 rpm (rotating shaker 3040, GFL) in 2 x 2 L PE bottles. Undissolved particles of the test item were removed by filtration (pore size 0.45 µm). The final concentration was below 1 mg/L.
- Controls: dilution water

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebra fish (Danio rerio)
- Source: AQUARIUM AM AEGI, Feldstr. 7, 30159 Hannover, Germany
- Length at study initiation (length definition, mean, range and SD): 2.96 cm
- Weight at study initiation (mean and range, SD): 0.4 g
- Maintenance of the brood fish: Holding was performed at the test facility at 23 ± 2 °C and diffuse light (0.1-1 0 1Jmol/²ms, natural photoperiod). The water was changed at least once per week. The dissolved oxygen concentration was more than 80 % of the air saturation value. Only zebrafish with at least 12 days of acclimatisation and mortality < 5 % within the last 7 days before the study starts was used in the test. No disease treatments were administered throughout holding and testing.

ACCLIMATION
- Acclimation period: 12 d
- Acclimation conditions (same as test or not): same as test
- Type and amount of food during acclimation: The amount of food was 4% of the fish body weight per feeding day. The test fish were not fed until 24 h before the test started. Food: Trouvit 40 I 2; MILKIVIT, D-86666 Bürgheim.
- Feeding frequency during acclimation: 3 times per week
- Health during acclimation (any mortality observed): no

FEEDING DURING TEST
- The fish were not fed during the test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

40 - 180 mg CaC03/L

Test temperature:

23 ± 2 °C

pH:

6.0 - 8.0

Dissolved oxygen:

> 80% air saturation value

Salinity:

not applicable

Nominal and measured concentrations:

Measured concentration below 1 mg/L in saturated solution.

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass-aquaria loosely covered by glass tops were used.
- Material, size, headspace, fill volume: The test volume was 4 L per vessel.
- Aeration: Gentle aeration was provided.
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: Fish density in the tanks was less than 1 g fish per liter test solution.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Tap water of local origin was used for holding and testing. The water was filtered on activated charcoal and aerated for at least 24 h to remove chlorine.
- Total organic carbon: /
- Particulate matter:/
- Metals:/
- Pesticides:/
- Chlorine:/
- Alkalinity:
- Ca/mg ratio: /
- Culture medium different from test medium: no
- Intervals of water quality measurement: at the beginning of the test and every 24 h

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: A natural photoperiod occurred during the test.
- Light intensity: 0.1 - 10 µE / m² • s

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): pH-value, temperature and oxygen saturation were measured in all vessels at the beginning of the test and every 24 h. Total hardness of the water was determined at the beginning out of the test control. During the test the room temperature was recorded continuously with a thermohygrograph.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: not applicable, Limit test
- Justification for using less concentrations than requested by guideline: The preliminary range finding test with the saturated solution didn't indicate effect on fishes.
- Range finding study: yes
- Results used to determine the conditions for the definitive study: Yes
- Test concentrations: < 1mg/L (measured); from a saturated solution set up with 100 mg/L

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

<= 1 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Remarks:

saturated solution

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: no
- Observations on body length and weight: not recorded
- Other biological observations: /
- Mortality of control: 0
- Other adverse effects control: 0
- Abnormal responses: not reported
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: test item was hardly soluble. A saturated solution was dispensed, applying 100 mg/L. The measured concentration was below 1mg/L.
- Effect concentrations exceeding solubility of substance in test medium: no, saturated solution was tested

Results with reference substance (positive control):

No reference item is recommended for this test according to the guideline.

Sublethal observations / clinical signs:

The concentration leading to 0 and 100 % mortality (LC0 and LC100) as well as the no observed effect concentration (NOEC) after 96 h was determined directly from the test results. LC50-values have not to be calculated in a limit test.

The results from the preliminary range finding test are presented in table 1. Symptoms of toxicity during the test are given in table 2. The cumulative mortality at each time of observation is shown in table 3. The test item was clearly dissolved throughout the test. The saturated solution of the test item caused no mortality or non-lethal effects. Therefore, the NOEC was reported at the saturated solution level (see table 4).

Table 1: Cumulative Mortality in [%] in the Preliminary Test (n = 5), based on the saturated solution, prepared with 100 mg/L)

Concentration	Test Duration [h]
	24	48	96
Saturated solution	0	0	0
Control	0	0	0

Table 2: Observations in the Test Vessels (n = 7). The number in brackets correspond to the following observation: (1) = Normal behaviour.

Concentration	Effect	Test Duration [h]
		2	24	48	72	96
Saturated solution	(1)	7/7	7/7	7/7	7/7	7/7
Control	(1)	7/7	7/7	7/7	7/7	7/7

Table 3: Cumulative mortality [%] in the Test Vessels

Concentration	Test Duration [h]
	2	24	48	72	96
Saturated solution	0	0	0	0	0
Control	0	0	0	0	0

Table 4: LC0-, LC100-, NOEC-Values (0 - 96 h)

LC100 = Lowest test item concentration with 100 % mortality after 96 h	Not applicable
LC0 = Highet test item concentration with 0 % mortality after 96 h	Saturated solution
NOEC (0-96 h) No observed effect concentration	Saturated solution

 

Validity criteria fulfilled:

yes

Conclusions:

In this study Niobium (II)-Oxide did not cause any effects in zebrafish after 96 h when tested in saturated solution.

Executive summary:

In a 96-h acute toxicity study, zebrafish (Danio rerio) were exposed to Niobium (II)-Oxide within a limit test at a saturated solution under static conditions. The measured concentration was below 1 mg/L. No lethal or sublethal effects were observed, hence, the NOEC wass determined to be above 1 mg a.i./L.

Based on the results of this study, Niobium (II)-Oxide would be classified as not toxic to D. rerio in saturated solution.

 

This toxicity study is classified as acceptable and satisfies the requirements of Directive 92/69/EC, Method C.1 toxicity study.

 

Results Synopsis

 

Test organism: D. rerio, length at test initiation: 2.96 cm; weight at test initiation: 0.4 g

Test Type: Static, limit test with saturated solution (a.i. < 1 mg/L)

 

NOEC:  saturated solution prepared with 100 mg/L, measured < 1 mg/L a.i.

Endpoint(s) Effected: mortality, behaviour

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2005-05-18 to 2005-05-22

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

not specified

Vehicle:

yes

Remarks:

Tweenum 80; no control with pure emulsifier conducted

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A supersaturated dispersion of the test chemical was continuously stirred over 96 hours, containing as well the emulsifier (1mg/L); Exposure solutions were prepared at the concentrations of 10, 20, 30, 50, 100 mg/L by the addition of the appropriate amounts of test substance to the test vessels.
- Eluate: /
- Differential loading: /
- Controls: natural water which has been settled by placing in the air about 24 hours with total hardness of between 10 and 250mg CaCO3 per liter and 8; pH 6.0 to 8.5.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Tweenum 80; emulsifier
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): 1mg/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): no

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Length at study initiation (length definition, mean, range and SD): 3.5 cm

ACCLIMATION
- Acclimation period: one week
- Health during acclimation (any mortality observed): ony healthy animals included in testing
- Type and amount of food during acclimation: not reported
- Feeding frequency during acclimation: not reported, but feedinf stopped one day prior to test
- Health during acclimation (any mortality observed):

FEEDING DURING TEST: no

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

10 - 250mg CaCO3/L

Test temperature:

22°C

pH:

6.0 to 8.5

Dissolved oxygen:

> 6.8 mg O2/L

Nominal and measured concentrations:

Nominal: 10, 20, 30, 50, 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass vessel of 25L
- Material, size, headspace, fill volume: Filling volume = 10L
- Aeration: Yes, air ventilation
- Type of flow-through (e.g. peristaltic or proportional diluter): not applicabel
- Renewal rate of test solution (frequency/flow rate): not reported
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 1
- Biomass loading rate: 10 fish per 10 L

TEST MEDIUM / WATER PARAMETERS - not reported

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: not reported
- Light intensity: not reported

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality, swimming beahviour, after 48, 72 and 96 h

TEST CONCENTRATIONS
- Spacing factor for test concentrations: unregular spacing
- Range finding study: not reported
- Test concentrations: 10, 20, 30, 50, 100 mg/L

Reference substance (positive control):

yes

Remarks:

potassium dichromate (100, 150, 200, 300, 500 mg/L)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: After the fish contacted the NIOBIUM(H)-OXIDE CAPACITOR GRADE, it had no response in low dose, it moved quickly in high dose, all fishes swim freely after 2 to 3 hours.
- Observations on body length and weight: not reported
- Other biological observations: not reported
- Mortality of control: 0
- Other adverse effects control: 0
- Abnormal responses: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: not reported
- Effect concentrations exceeding solubility of substance in test medium: yes; emulsifier was applied

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Mortality: after 96h: 150 mg/L 20%; 200 mg/L 30%, 300 mg/L 90%; 500 mg/L 100%
- LC50: 213 mg/L (96h)

Reported statistics and error estimates:

Positive control: LC50 (96h) = 213 mg/L [95% confidence limit 180.6 - 259.9 mg/L]

Sublethal observations / clinical signs:

The toxicity of the positive control (potassium dichromate) to Brachydanio rerio H.B. is displayed in table 1, respectively the mortality in percent caused by the test item is presented in table 2.

Table 1: Toxicity of potassium dichromate on Brachydanio rerio H.B.

Concentrations (mg/L)	Mortality (%)
	48 h	72 h	96 h
0	0	0	0
100	0	0	0
150	0	20	20
200	10	30	30
300	50	50	90
500	100	100	100
LC 50 (mg/L)	289.6	252.8	213.0
95% confidence limit (mg/L)	246.5-359.8	206.5-3217.6	180.6-259.9

 

Table 2: Toxicity of NIOBIUM(II)-OXIDE CAPACITOR GRADE on Brachydanio rerio H.B.

Concentrations (mg/L)	Mortality (%)
	24 h	48 h	72 h	96 h
0		0	0	0
10		0	0	0
20		0	20	20
30		10	30	30
50		50	50	90
100		100	100	100

Validity criteria fulfilled:

yes

Conclusions:

In accordance with the OECD Guidelines 203 the LC50 (96h, Danio rerio) is greater than 100 mg/L (nominal concentration).
No effects were observed at any of the concentrations tested.

Executive summary:

In a 96-h acute toxicity study, zebrafish (Danio rerio) were exposed to Niobium (II)-Oxide nominal concentrations of 0 (solvent control), 10, 20, 30, 50, 100 mg/L under semi-static conditions (vehicle: Tweenum 80). No sublethal effects were observed, hence, the NOEC was determined to be above 100 mg/L.

Based on the results of this study, Niobium (II)-Oxide would be classified as not toxic to D. rerio at the saturated solution level in accordance with the CLP.

 

This toxicity study is classified as acceptable and satisfies the guideline requirement for the OECD TG 203 Fish, Acute Toxicity Test toxicity study.

 

Results Synopsis

 

Test organism: D. rerio, length at test initiation: 3.5 cm; weight at test initiation: 0.4 g

Test Type: Semi-static

 

NOEC:  > 100 mg/L

Endpoint(s) Effected: mortality, behaviour

Description of key information

Scheerbaum (2003) conducted a limit test in accordance with the EC Directive 92/69/C1 L 383 A (1992) from 2003. The test item was not acute toxic to zebrafish tested in saturated solution. The measured content of Niobium was < 1 mg/L.

These results are supported by Lili (2005). The acute toxicity of the test item zebrafish was tested according to OECD Guideline 203 at concentrations up to 100 mg/L using an emulsifier. In this study nominal concentrations are used, applying an emulsifier to keep the hardly soluble test item in solution. No effects on zebrafish were seen throughout the study. The LC₅₀ was calculated as above 100 mg/L.

Thus, it can be concluded that the NOEC for 96h exposure of the test item to zebrafish is above 1 mg/L (measured concentration).