Tellurium

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2012-05-25 to 2012-05-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

see section 13.1 for read-across justification

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Water samples (2 x 20 mL) for chemical analysis were taken of fresh test media at test start (before fish addition) at 48 h (aged test solution and newly prepared solution) and at test end.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Due to the very low water solubility of the test item, a Water Accommodated Fraction (WAF) of the test item was applied.
A test preparation with a loading of 100 mg test item per litre was prepared according to the OECD guidance No. 23 and stirred slowly, using a star shape
magnetic stirring bar for about 48 h at room temperature (about 20°C).
Finally, the test preparation was filtered using a 0.2 μm filter (Sartolab 150v, PES-membrane, Sartorius Stedim Biotech S.A., Aubagne Cedex, France) to separate insoluble parts from the aqueous phase.
The filtrated WAF was used to prepare different diluted eluates.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Strain: Oncorhynchus mykiss (Teleostei, Salmonidae)
- Source: Sauerländer Forellen GmbH, Saalhauser Straße 8, 57368 Lennestadt-Gleierbrück, Germany
- Age at study initiation (mean and range, SD):
- Length at study initiation (length definition, mean, range and SD): mean 4.6 cm, SD 0.2 cm
- Weight at study initiation (mean and range, SD): mean 0.98 g, SD 0.2 g
- Method of breeding: Fertilised eggs in eye-point stage were transferred to the fish holding device.
- Feeding during test
No feeding of the fish occurred during the test as well as 24 h before test start.

ACCLIMATION
- Acclimation period:
- Acclimation conditions (same as test or not): same as test conditions
- Type and amount of food: Fish were fed ad-libitum throughout the holding period with trout food daily.
- Health during acclimation (any mortality observed): The criteria of the test guideline were followed. Only healthy fish without diseases and abnormalities were used in the study. Mortality of the batch was less than 5 % during the last week before start of the study.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

Mortality and clinical signs of the fish were recorded at 3 h, 24 h, 48 h, 72 h and 96 h after addition of the test solution.

Hardness:

Total hardness: 1.0 mmol/L

Test temperature:

The temperature was in the range of 15.3-15.5°C.

pH:

The pH in the test vessels was between 8.2 and 8.6, showed no influence of tellurium dioxide, and remained constant until the end of the study.

Dissolved oxygen:

The water was aerated to the point of oxygen saturation, in all test vessels between 99 % and 103 %.

Details on test conditions:

TEST SYSTEM
- Test vessel: full glass aquaria of 28 L with 20 L of test solution
- Aeration: slightly aerated via a glass capillary
- Type of flow-through (e.g. peristaltic or proportional diluter): A complete renewal of the test media was performed after 48 h.
- Renewal rate of test solution (frequency/flow rate):
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Purified drinking water
- Total organic carbon: DOC content - 0.7426 mg/L
- Total hardness: 1.1 mmol/L
- Metals: copper < 1.47 μg/L; iron < 2.92 μg/L ; manganese < 0.79 μg/L; zinc < 3.61 μg/L
- Chlorine: total residual chlorine < 0.02 mg/L
- Alkalinity: 1.6 mmol/L
- Conductivity: 234.8 µS/cm
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: light/dark cycle of 14/10 h


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality and clinical signs (sub-lethal and abnormal behaviour) of the fish were recorded at 3 h, 24 h, 48 h, 72 h and 96 h after addition of the test solution.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 50 % serial dilution of the maximum nominal test concentration

- Range finding study
- Test concentrations: 100, 10 1 mg/L WAF
- Results used to determine the conditions for the definitive study:
Mortality was observed at the concentration of 100 mg/L after 48 h (one animal) 72 h (further 3 animals).

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 46.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

dissolved

Remarks:

Tellurium dioxide

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 37.1 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

dissolved

Remarks:

Tellurium

Basis for effect:

mortality (fish)

Details on results:

Neither clinical signs nor mortality were observed throughout the study.
The LC50 of tellurium dioxide was determined to be > 100 mg/L (nominal), corresponding to > 46.4 mg/L (mean measured).

Reported statistics and error estimates:

It was not possible to determine the LC50 because no mortality was observed. For the same reason no statistical evaluation was performed.

Validity criteria fulfilled:

yes

Conclusions:

The LC50 of tellurium dioxide was determined to be > 100 mg/L (nominal), corresponding to > 46.4 mg/L (mean measured).

Executive summary:

In a 96-h acute toxicity study, rainbow trout (Oncorhynchus mykiss) were exposed to tellurium dioxide at concentrations of 0, 6.25, 12.5, 25.0, 50.0, and 100.0 mg/L nominal under semic-static conditions. Each treatment consisted of seven fish.

Due to the very low water solubility of tellurium dioxide, a Water Accommodated Fraction (WAF) of the test item was applied.

The arithmetic means of measured concentrations were determined to be 0, 3.00, 6.05, 11.5, 24.2 and 46.4 mg tellurium dioxide/L, by ICP-MS.

Neither clinical signs nor mortality could be observed throughout the study.

The 96-h LC50 was:

> 100 mg tellurium dioxide/L (nominal)

> 46.4 mg tellurium dioxide/L (mean measured)

> 37.1 mg tellurium/L (mean measured)

All validity criteria for controls mentioned by the OECD guideline were met:

Mortality did not exceed 10 % in the controls at the end of the test.

The dissolved oxygen concentration was ≥ 60 % of the air saturation in the test vessels and control throughout the test.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-05-25 to 2012-05-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Water samples (2 x 20 mL) for chemical analysis were taken of fresh test media at test start (before fish addition) at 48 h (aged test solution and newly prepared solution) and at test end.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Due to the very low water solubility of the test item, a Water Accommodated Fraction (WAF) of the test item was applied.
A test preparation with a loading of 100 mg test item per litre was prepared according to the OECD guidance No. 23 and stirred slowly, using a star shape
magnetic stirring bar for about 48 h at room temperature (about 20°C).
Finally, the test preparation was filtered using a 0.2 μm filter (Sartolab 150v, PES-membrane, Sartorius Stedim Biotech S.A., Aubagne Cedex, France) to separate insoluble parts from the aqueous phase.
The filtrated WAF was used to prepare different diluted eluates.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Strain: Oncorhynchus mykiss (Teleostei, Salmonidae)
- Source: Sauerländer Forellen GmbH, Saalhauser Straße 8, 57368 Lennestadt-Gleierbrück, Germany
- Age at study initiation (mean and range, SD):
- Length at study initiation (length definition, mean, range and SD): mean 4.6 cm, SD 0.2 cm
- Weight at study initiation (mean and range, SD): mean 0.98 g, SD 0.2 g
- Method of breeding: Fertilised eggs in eye-point stage were transferred to the fish holding device.
- Feeding during test
No feeding of the fish occurred during the test as well as 24 h before test start.

ACCLIMATION
- Acclimation period:
- Acclimation conditions (same as test or not): same as test conditions
- Type and amount of food: Fish were fed ad-libitum throughout the holding period with trout food daily.
- Health during acclimation (any mortality observed): The criteria of the test guideline were followed. Only healthy fish without diseases and abnormalities were used in the study. Mortality of the batch was less than 5 % during the last week before start of the study.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

Mortality and clinical signs of the fish were recorded at 3 h, 24 h, 48 h, 72 h and 96 h after addition of the test solution.

Hardness:

Total hardness: 1.0 mmol/L

Test temperature:

The temperature was in the range of 15.3-15.5°C.

pH:

The pH in the test vessels was between 8.2 and 8.6, showed no influence of tellurium dioxide, and remained constant until the end of the study.

Dissolved oxygen:

The water was aerated to the point of oxygen saturation, in all test vessels between 99 % and 103 %.

Details on test conditions:

TEST SYSTEM
- Test vessel: full glass aquaria of 28 L with 20 L of test solution
- Aeration: slightly aerated via a glass capillary
- Type of flow-through (e.g. peristaltic or proportional diluter): A complete renewal of the test media was performed after 48 h.
- Renewal rate of test solution (frequency/flow rate):
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Purified drinking water
- Total organic carbon: DOC content - 0.7426 mg/L
- Total hardness: 1.1 mmol/L
- Metals: copper < 1.47 μg/L; iron < 2.92 μg/L ; manganese < 0.79 μg/L; zinc < 3.61 μg/L
- Chlorine: total residual chlorine < 0.02 mg/L
- Alkalinity: 1.6 mmol/L
- Conductivity: 234.8 µS/cm
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: light/dark cycle of 14/10 h


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality and clinical signs (sub-lethal and abnormal behaviour) of the fish were recorded at 3 h, 24 h, 48 h, 72 h and 96 h after addition of the test solution.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 50 % serial dilution of the maximum nominal test concentration

- Range finding study
- Test concentrations: 100, 10 1 mg/L WAF
- Results used to determine the conditions for the definitive study:
Mortality was observed at the concentration of 100 mg/L after 48 h (one animal) 72 h (further 3 animals).

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 46.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

dissolved

Remarks:

Tellurium dioxide

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 37.1 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

dissolved

Remarks:

Tellurium

Basis for effect:

mortality (fish)

Details on results:

Neither clinical signs nor mortality were observed throughout the study.
The LC50 of tellurium dioxide was determined to be > 100 mg/L (nominal), corresponding to > 46.4 mg/L (mean measured).

Reported statistics and error estimates:

It was not possible to determine the LC50 because no mortality was observed. For the same reason no statistical evaluation was performed.

Validity criteria fulfilled:

yes

Conclusions:

The LC50 of tellurium dioxide was determined to be > 100 mg/L (nominal), corresponding to > 46.4 mg/L (mean measured).

Executive summary:

In a 96-h acute toxicity study, rainbow trout (Oncorhynchus mykiss) were exposed to tellurium dioxide at concentrations of 0, 6.25, 12.5, 25.0, 50.0, and 100.0 mg/L nominal under semic-static conditions. Each treatment consisted of seven fish.

Due to the very low water solubility of tellurium dioxide, a Water Accommodated Fraction (WAF) of the test item was applied.

The arithmetic means of measured concentrations were determined to be 0, 3.00, 6.05, 11.5, 24.2 and 46.4 mg tellurium dioxide/L, by ICP-MS.

Neither clinical signs nor mortality could be observed throughout the study.

The 96-h LC50 was:

> 100 mg tellurium dioxide/L (nominal)

> 46.4 mg tellurium dioxide/L (mean measured)

> 37.1 mg tellurium/L (mean measured)

All validity criteria for controls mentioned by the OECD guideline were met:

Mortality did not exceed 10 % in the controls at the end of the test.

The dissolved oxygen concentration was ≥ 60 % of the air saturation in the test vessels and control throughout the test.

Description of key information

Study was conducted according to Regulation (EC) No 440/2008: test method C. 1

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

37.1 mg/L

Additional information

In a 96-h acute toxicity study, rainbow trout (Oncorhynchus mykiss) were exposed to tellurium dioxide at concentrations of 0, 6.25, 12.5, 25.0, 50.0, and 100.0 mg/L nominal under semic-static conditions. Each treatment consisted of seven fish.

Due to the very low water solubility of tellurium dioxide, a Water Accommodated Fraction (WAF) of the test item was applied.

The arithmetic means of measured concentrations were determined to be 0, 3.00, 6.05, 11.5, 24.2 and 46.4 mg tellurium dioxide/L, by ICP-MS.

Neither clinical signs nor mortality could be observed throughout the study.

 

The 96-h LC50 was:

> 100 mg tellurium dioxide/L (nominal)

> 46.4 mg tellurium dioxide/L (mean measured)

> 37.1 mg tellurium/L (mean measured)

 

Justification for read-across:

This read-across is based on the hypothesis that source and target substances do possess similar ecotoxicological properties.

Since the physico-chemical behaviour of elemental Tellurium and Tellurium dioxide is the same with regard to their metabolic fate (reduction to the Telluride anion) there seems to be good evidence that Tellurium from different moieties will behave very similar with regard to systemic toxicity.

Elemental Tellurium and Tellurium dioxide are relatively poorly water soluble and their systemic uptake by environmental organisms will be directly comparable.

Thus the bioavailability will be an important factor for assessment of ecotoxicity of both substances. The water solubility of both substances is relatively low, with 1.7 and 2.5 mg/L for Tellurium and Tellurium dioxide, respectively.

Data from transformation dissolution tests at different pH values and loadings are available for both substances, indicating Tellurium dioxide to be more soluble at pH 8.

 

Corresponding standard information requirement	Source substance Tellurium dioxide	Target substance Tellurium
Water solubility	Transformation dissolution test: OECD guideline 29   Target pH 8 at 21.5 °C. Loadings TeO2: Te concentrations after 7 days: 1 mg/L: 698.9 µg/L 10 mg/L: 6.254 mg/L 100 mg/L: 30.72 mg/L	Transformation dissolution test: OECD guideline 29   Target pH 8 at 21.5 °C. Loadings: Te concentrations after 7 days: 1 mg/L: 20.02 µg/L 10 mg/L: 183.3 µg/L 100 mg/L:1.762 mg/L.
	Water solubility: OECD guideline 105   2.5 mg/L at 23 °C pH 6.4	Water solubility: OECD guideline 105   1.7 mg/L at 20 °C pH 5.5 – 6.3

 

Underlying the basic assumption that effects caused by the bioavailable metal fraction and the same toxicokinetic behaviour (outlined in detail in the chapter toxicokinetic), ecotoxicity data from the relatively higher soluble Tellurium dioxide were considered appropriate for the ecotoxicity assessment of Tellurium.

In conclusion read-across is considered an appropriate adaptation for ecotoxicological endpoints to meet the standard information requirements according to REACH Regulation.

A detailed justification for read-across describing the toxicokinetic profile, comparing physico-chemical and toxicological properties as well as classification and labelling is outlined in IUCLID chapter 13 in a separate paper.