Sodium bis[4-hydroxy-3-[(2-hydroxy-1-naphthyl)azo]benzenesulphonamidato(2-)]cobaltate(1-)

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples of the test solutions were collected at test initiation and test completion for confirmatory analysis. Samples were collected in glass amber bottles (~40 mL). At test initiation, the samples of test solution were collected from the freshly prepared test solutions. At test completion, the samples of test solution were collected from pooled solution from the test vessels themselves. The samples were stored at room temperature until analyzed.

Vehicle:

no

Details on test solutions:

Since the test item has a water solubility of 4.8 g/L at 20°C, a stock solution was prepared at 100 mg test item/L and test solutions were prepared as dilutions of this stock. To prepare the stock solution (100 mg/L), 0.2001 g of test item, was weighed and rinsed into a 2L glass volumetric flask containing approximately 1200 mL of daphnia dilution water. The solution, after being stirred for approximately 30 minutes, was then brought up to the 2 L mark using daphnia dilution water and mixed well by inversion. Five test concentrations were prepared from this stock solution and tested with a laboratory (negative) control (dilution water only). Each 250 mL glass beaker test vessel was verified at 200 mL using a Type A glass graduated cylinder. Each test vessel was then rinsed with the appropriate test solution before the 200 mL test volume was dispensed. Four replicate test vessels of each test concentration and of the laboratory (negative) control were prepared. The stock solution appeared a vivid purple-red and was difficult to see through without the use of a strong light source. There were flakes of test item suspended in the stock solution. The colour of the test solutions ranged from pale red in the 6.25 mg/L test concentration and gradually darkened to a vivid purple-red in the 100 mg/L test concentration. Suspended particles of test item were visible in the 50 mg/L and 100 mg/L test concentrations. The negative (laboratory) control appeared clear and colourless.

Test organisms (species):

Daphnia magna

Details on test organisms:

Test species: Daphnia magna
Age at test initiation: <24 hr
Source of test organisms: In-house culture; original culture was obtained from Aquatic BioSystems (Fort Collins, CO) in April 2016 (identified by EcoAnalysts Inc. on March 10, 2016 as D. magna)
Test organism ID: AB161115
Mortality in 7 days preceding test (%): 3.2%

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

100 mg/L CaCO3

Test temperature:

19.7 °C

pH:

8.1

Dissolved oxygen:

9.1

Salinity:

n/a

Nominal and measured concentrations:

Nominal Concentrations of the Test Item: 6.25, 12.5, 25, 50, and 100 mg/L
Measured Concentrations of test Item: 5.0, 9.6, 18.3, 34.1, and 52.9 mg/L

Details on test conditions:

Test type: Static
Duration: 48 hr
Test species: Daphnia magna
Age at test initiation: <24hr
Source of test organisms: In-house culture; original culture was obtained from Aquatic BioSystems (Fort Collins, CO) in April 2016 (identified by EcoAnalysts Inc. on March 10, 2016 as D. magna)
Test organism ID: AB161115
Mortality in 7 days preceding test (%): 3.2 %
Photo‐period 16h light: 8hr dark with a 30 minute transition period
Light intensity: 570-661 lux
pH: 7.9-8.0
Test solution temperature: 19.0 to 20.3 °C
Dissolved oxygen: 8.9 to 9.1 mg/L
Feeding: None
Test vessels: 250 mL glass beakers covered with Plexiglas
Test volume: 200 mL
Test organisms per replicate: Five
Replicates: Four
Aeration: None
Dilution water source: Moderately hard, reconstituted water (hardness of 100 mg/L as CaCO3); aerated before use in the test.

Reference substance (positive control):

yes

Remarks:

zinc sulphate heptahydrate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 52.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 52.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 52.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

yes

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other:

Remarks:

The study was conducted according to OECD guideline 202 under consideration of GLP. The reliability of the study was originally rated with 1 (reliable without ristrictions). However, the final report signed by the Study Director on September 24, 2015 was not archived as required under Section 10.1 a) of ENV/MC/CHEM(98)17 "OECD Principles on Good Laboratory Practice". As such, the original final report signed by the Study Director on September 24, 2015 cannot be located - only a scanned copy was available. This does not impact the raw data and/or study outcomes and/or conclusions of the Study. Therefore, the study has to be rated with 2 due to the missing GLP compliance. However, this does not in any way affect the quality of the study. In regards to the overall assessment the results are still regarded as reliable without restrictions.

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 of the test solutions were collected at test initiation and test completion for confirmatory analysis. Samples were collected in glass amber bottles (~40 mL). At test initiation, the samples of test solution were collected from the freshly prepared test solutions. At test completion, the samples of test solution were collected from pooled solution from the test vessels themselves. The samples were stored at room temperature until analyzed.

Vehicle:

no

Details on test solutions:

Since the test item is soluble in destilled water, a stock solution was prepared at 200 mg/L and 6.25 mg/L, 12.5 mg/L, 25 mg/L, 50 mg/L and 100 mg/L test solutions were prepared from this stock solution using daphnia water. To prepare stock solution (200 mg/L), 0.4000 g of test item was weighed onto a watch glass and washed down, using daphnia water, to approximately 1200 mL of daphnia water (dilution water) in a 2L glass volumetric flask and stirred using a magnetic stirrer for approximate 30 minutes. Daphnia water was added up to the 2L mark and the stock solution was mixed well by inversion. Some fine particles were observed suspended in the stock solution and adhering to the neck of the 2L volumetric flask. The Laboratory control appeared clear and colourless. The 6.25 mg/L test solutions up to the 100 mg/L test solutions increased in colour from very light pale pink to a deep crimson/purple colour in the 100mg/L test solution. The 50 mg/L and 100mg/L test solutions appeared slightly opaque. After preparation, all test solutions were clear with no debris noted at bottom of the test vessels. The test solution colour remained unchanged throughout the test, however at test completion, reddish grains were observed at the bottom of the test vessels in the 12.5 mg/L test solution, and dark red/purple precipitate was observed in the 50 mg/L and 100 mg/L test vessels.

Test organisms (species):

Daphnia magna

Details on test organisms:

Test species: Daphnia magna
Age at test initiation: <24 hr
Source of test organisms: In-house culture; original culture was obtained from Aquatic BioSystems (Fort Collins, CO) in June 2013 (identified by EcoAnalysts Inc. on 20 January 2011 as D. magna)
Test organism ID: AB150630
Mortality in 7 days preceding test (%): 0 %

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

104 mg/L CaCO3

Test temperature:

20.5 °C

pH:

8.3

Dissolved oxygen:

9.1

Salinity:

n/a

Nominal and measured concentrations:

Nominal Concentrations of the Test Item: 6.25, 12.5, 25, 50 and 100 mg/L
Measured Concentrations of test Item: 5.0 mg/L, 10.1 mg/L, 18.8 mg/L, 35.3 mg/L, and 66.9 mg/L

Details on test conditions:

Test type: Static
Duration: 48 hr
Test species: Daphnia magna
Age at test initiation: <24‐hr
Source of test organisms: In‐house culture; original culture was obtained from Aquatic BioSystems (Fort Collins, CO) in June 2013 (identified by EcoAnalysts Inc. on 20 January 2011 as D. magna)
Test organism ID: AB150630
Mortality in 7 days preceding test (%): 0 %
Photo‐period 16‐h light: 8‐hr dark with a 30 minute transition period
Light intensity: 591 – 636 lux
pH: 8.2 – 8.3
Test solution temperature: 20.4 to 21.0 °C
Dissolved oxygen: 8.8 to 9.2 mg/L
Feeding: None
Test vessels: ~250 mL glass beakers covered with Plexiglas
Test volume: 200 mL
Test organisms per replicate: Five
Replicates: Four
Aeration: None
Dilution water source: Moderately hard, reconstituted water (hardness of 104 mg/L as CaCO3); aerated before use in the test.

Reference substance (positive control):

yes

Remarks:

zinc sulphate heptahydrate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 66.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 66.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 66.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

yes

Description of key information

There is a high probability that the product is not acutely harmful to aquatic invertebrates. 

Additional information

The short-term toxicity of the compound towards aquatic invertebrates was assessed in two acute toxicity studies with Daphnia magna as test organism. The studies were conducted according to OECD test guideline 202. The reliability of both studies was originally rated with 1 (reliable without restrictions). However, the first study from 2015 (study no. TOX1506) lost its GLP status. The final report signed by the Study Director on September 24, 2015 was not archived as required under Section 10.1 a) of ENV/MC/CHEM(98)17 "OECD Principles on Good Laboratory Practice". As such, the original final report signed by the Study Director on September 24, 2015 cannot be located - only a scanned copy was available. This does not impact the raw data and/or study outcomes and/or conclusions of the Study. Therefore, the study has to be rated with 2 due to the missing GLP compliance. However, this does not in any way affect the quality of the study. In regards to the overall assessment the results are still regarded as reliable without restrictions. Therefore, a second study was conducted with the same batch of test substance. 

In both studies, nominal test solutions of 0, 6.25, 12.5, 25, 50, and 100 mg/L were used. The color of the test solutions increased from very light pale pink to a deep purple color. In the first study from 2015 the test solution color remained unchanged throughout the test, however at test completion, reddish grains were observed at the bottom of the test vessels in the 12.5 mg/L test solution, and dark red/purple precipitate was observed in the 50 mg/L and 100 mg/L test vessels. In the second study from 2017 suspended particles of test item were visible in the 50 mg/L and 100 mg/L test concentrations from the start of the test. Throughout test the color of the test solutions remained consistent. The mean measured concentrations were 5, 10.1, 18.8, 35.3, and 66.9 in the first study and 5.0, 9.6, 18.3, 34.1, and 52.9 mg/L in the second study. As undissolved material was present in both studies it can be concluded that the daphnids in the test solutions were exposed to the highest achievable concentration (nominal 100 mg/L; measured 66.9 mg/L and 52.9 mg/L, respectively). Neither study revealed effects in any of the concentration groups, not even in the highest one (nominal 100 mg/L) which displayed precipitated test material.

In conclusion, there is a high probability that the compound is not acutely harmful to aquatic invertebrates.