Cobalt disodium ethylenediaminetetraacetate

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:

From October 10 to 12, 2018

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)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS
- Strain/clone:
- Justification for species other than prescribed by test guideline:
- Source: - Origin: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), 14195 Berlin, Germany; - Breeder: Noack Laboratorien GmbH, Käthe-Paulus-Str. 1, 31157 Sarstedt, Germany
- Age of parental stock (mean and range, SD): Less than 24 hours old
- - Feeding during test: no

ACCLIMATION
- Acclimation period: About 3.6 hours in the dilution water
- Type and amount of food: mix of unicellular green algae
- Feeding frequency: 5 times per week ad libitum

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

18 - 22 °C, constant within ± 1 °C

Nominal and measured concentrations:

100 mg/l nominal concentration (0.754 geom. mean measured concentration).
Measured concentration at the start and at the end of exposure always between 5 and 6 %.

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers (4 (ID) x 7 (H) cm)
- Type (delete if not applicable): Closed (loosely covered with watch glasses)
- Material, size, headspace, fill volume: glass, 50 mL capacity
- Renewal rate of test solution (frequency/flow rate): solutions were renewed after 24 hours
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.754 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: nominal concentration = 100 mg/l

Details on results:

The measured concentration of cobalt at the start of the exposure (0 and 24 hours) and at the end of the exposure (24 and 48 hours) was between of 5 and 6% of the nominal concentration because most of the Co-complex remained undissociated.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50: 2.09 mg/l based on nominal concentration

Validity criteria fulfilled:

yes

Conclusions:

EC50 > 100 mg/l based on nominal concentration.

Executive summary:

Method

In the acute immobilization test with Daphnia magna (STRAUS), the effects of the test item were determined at the test facility according to OECD guideline 202.

The study was conducted under semi-static conditions over a period of 48 hours with the limit concentration of 100 mg/L of the test item.The test solution was shaken manually until the solution was visually clear. The limit concentration was colorless and visually clear throughout the exposure.

Twenty daphnids (divided into 4 replicates with 5 daphnids each) were exposed to the limit concentration and the control.

The concentration of Cobalt, component of the test item, was analytically verified via spectrophotometric analysis in the fresh media of the limit concentration and in the control at the start of the exposure and at the renewal of the test solutions (0 and 24 hours) and in the 24-hours old media at the renewal and at the end of the test (24 and 48 hours).

The measured concentration of Cobaltat the start of the exposure (0 and 24 hours) and at the end of the exposure (24 and 48 hours) was between of 5 and 6% of the nominal concentration. The geometric mean measured concentration of Cobalt was 0.754 mg/L.

Since the recoveries of the measured Cobalt concentration were not within ± 20% of the nominal concentration,the effect concentrations are based on geometric mean measured concentration of Cobalt. Additionally, the effect levels are given based on the nominal concentration of the test item.

The validity criteria of the test guidelines were fulfilled.

 

Results

In the limit concentration 100 mg/Lof the test item, which corresponds to the geometric mean measured concentration of 0.754 mg/L of the component Cobalt, no effects on Daphnia magna were observed.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Study period:

From October 10 to 12, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

For the detailed read across justification see the document provided in section 13.2 of this dossier.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

assessment report

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS
- Strain/clone:
- Justification for species other than prescribed by test guideline:
- Source: - Origin: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), 14195 Berlin, Germany; - Breeder: Noack Laboratorien GmbH, Käthe-Paulus-Str. 1, 31157 Sarstedt, Germany
- Age of parental stock (mean and range, SD): Less than 24 hours old
- - Feeding during test: no

ACCLIMATION
- Acclimation period: About 3.6 hours in the dilution water
- Type and amount of food: mix of unicellular green algae
- Feeding frequency: 5 times per week ad libitum

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

18 - 22 °C, constant within ± 1 °C

Nominal and measured concentrations:

100 mg/l nominal concentration (0.754 geom. mean measured concentration).
Measured concentration at the start and at the end of exposure always between 5 and 6 %.

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers (4 (ID) x 7 (H) cm)
- Type (delete if not applicable): Closed (loosely covered with watch glasses)
- Material, size, headspace, fill volume: glass, 50 mL capacity
- Renewal rate of test solution (frequency/flow rate): solutions were renewed after 24 hours
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.754 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: nominal concentration = 100 mg/l

Details on results:

The measured concentration of cobalt at the start of the exposure (0 and 24 hours) and at the end of the exposure (24 and 48 hours) was between of 5 and 6% of the nominal concentration because most of the Co-complex remained undissociated.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50: 2.09 mg/l based on nominal concentration

Validity criteria fulfilled:

yes

Conclusions:

EC50 > 100 mg/l based on nominal concentration

Executive summary:

Method

In the acute immobilization test with Daphnia magna (STRAUS), the effects of the test item were determined at the test facility according to OECD guideline 202.

The study was conducted under semi-static conditions over a period of 48 hours with the limit concentration of 100 mg/L of the test item.The test solution was shaken manually until the solution was visually clear. The limit concentration was colorless and visually clear throughout the exposure.

Twenty daphnids (divided into 4 replicates with 5 daphnids each) were exposed to the limit concentration and the control.

The concentration of Cobalt, component of the test item, was analytically verified via spectrophotometric analysis in the fresh media of the limit concentration and in the control at the start of the exposure and at the renewal of the test solutions (0 and 24 hours) and in the 24-hours old media at the renewal and at the end of the test (24 and 48 hours).

The measured concentration of Cobaltat the start of the exposure (0 and 24 hours) and at the end of the exposure (24 and 48 hours) was between of 5 and 6% of the nominal concentration. The geometric mean measured concentration of Cobalt was 0.754 mg/L.

Since the recoveries of the measured Cobalt concentration were not within ± 20% of the nominal concentration,the effect concentrations are based on geometric mean measured concentration of Cobalt. Additionally, the effect levels are given based on the nominal concentration of the test item.

The validity criteria of the test guidelines were fulfilled.

 

Results

In the limit concentration 100 mg/Lof the test item, which corresponds to the geometric mean measured concentration of 0.754 mg/L of the component Cobalt, no effects on Daphnia magna were observed.

Description of key information

A study according to OECD 202 was conducted on Co(NH4)EDTA. A read across approach to CoNa2EDTA is reasonable (see the justification provided in section 13.2 of this dossier). Based on the nominal concentrations of the Co-EDTA-complex it can be stated that the EC50 is > 100 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L