Acetic acid, (ethylenedinitrilo)tetra-, cobalt salt

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

The study is well-documented by the publication and thus acceptable for assessment.

Qualifier:

according to guideline

Guideline:

other:

Version / remarks:

U.S. EPA 1985a, Peltier and Weber, 1985

Principles of method if other than guideline:

The study is well-documented by the publication and thus acceptable for assessment. The study is based on EPA guidelines (Peltier and Weber, 1985).

GLP compliance:

not specified

Specific details on test material used for the study:

reagent grade, Baker Chemical Co., N.Y.

Analytical monitoring:

yes

Details on sampling:

All cobalt samples (approximately 100 ml per sample) were immediately preserved with 4 drops of concentrated nitric acid to a pH < 2.0 (APHA, 1990). Each sample was a composite of all replicates for that treatment.

Vehicle:

not specified

Test organisms (species):

Ceriodaphnia dubia

Details on test organisms:

Tests were performed on two species: Ceriodaphnia dubia and Pimephales promelas

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

50, 200, 400, and 800 mgll hardness as CaCO3

Nominal and measured concentrations:

Measured concentrations:
- hardness 50 mg/l: 297.5, 1266, 3405 µg/l based on cobalt
- hardness 200 mg/l: 286.7, 1216, 5926 µg/l based on cobalt
- hardness 400 mg/l: 276.7, 1203, 5920 µg/l based on cobalt
- hardness 800 mg/l: 230.0, 976, 5275 µg/l based on cobalt

Details on test conditions:

Ceriodaphnia dubia used in this study were cultured in 20% dilute mineral water consisting of 20% Perrier® and 80% distilled water, (aerated for 48 h) which was then diluted 1:5 with clean filtered pond water. Both the Perrier® and the pond water supply the necessary nutrients for normal C. dubia growth and reproduction. Organisms were held at 25 °C under a 16 h light:8 h dark photoperiod. C. dubia less than 24 h old were used toxicity tests. Tine feeding regime consisted of 0.1 ml digested cerophyll and TetraMin® and 0.1 ml Selenastrum
(approx. 3 x 106 cells/ml) fed daily to each brood culture and all 15 ml test chambers (Horning and Weber. 1989).

Temperature. pH, dissolved oxygen, and conductivity were measured daily.
At 24 h, test concentrations were renewed with fresh solutions.

Reference substance (positive control):

no

Key result

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

2.3 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

element

Basis for effect:

mortality

Remarks on result:

other: hardness 50 mg/l

Key result

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

5.3 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

element

Basis for effect:

mortality

Remarks on result:

other: hardness 800 mg/l

Validity criteria fulfilled:

not specified

Conclusions:

The 24 h LC50 values based on cobalt ions for C. dubia increased with increasing water hardness, from 2.3 to 5.3 mg/l as the water hardness increased from 50 to 800 mg/l hardness as CaCO3.

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Edetic acid is known to be non-ecotoxic towards aquatic invertebrates as proved by studies. Thus, the toxicity of EDTA-CoH2 towards aquatic invertebrates is caused by the cobalt moiety only. As a worst-case approach it is assumed that the metal is fully released from the complex within short time. As proved by the evaluation of biodegradation of the substance the metal is released over longer period which lowers the concentrations of cobalt available in water and thus lowers the toxicity of the complex. Because metal ions bound in complexes are known to be less ecotoxic than the free ions, it can be concluded that the ecotoxicity of EDTA-CoH2 might be overestimated but not underestimated by this approach.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other:

Version / remarks:

U.S. EPA 1985a, Peltier and Weber, 1985

Principles of method if other than guideline:

The study is well-documented by the publication and thus acceptable for assessment. The study is based on EPA guidelines (Peltier and Weber, 1985).

GLP compliance:

not specified

Specific details on test material used for the study:

reagent grade, Baker Chemical Co., N.Y.

Analytical monitoring:

yes

Details on sampling:

All cobalt samples (approximately 100 ml per sample) were immediately preserved with 4 drops of concentrated nitric acid to a pH < 2.0 (APHA, 1990). Each sample was a composite of all replicates for that treatment.

Vehicle:

not specified

Test organisms (species):

Ceriodaphnia dubia

Details on test organisms:

Tests were performed on two species: Ceriodaphnia dubia and Pimephales promelas

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

50, 200, 400, and 800 mgll hardness as CaCO3

Nominal and measured concentrations:

Measured concentrations:
- hardness 50 mg/l: 297.5, 1266, 3405 µg/l based on cobalt
- hardness 200 mg/l: 286.7, 1216, 5926 µg/l based on cobalt
- hardness 400 mg/l: 276.7, 1203, 5920 µg/l based on cobalt
- hardness 800 mg/l: 230.0, 976, 5275 µg/l based on cobalt

Details on test conditions:

Ceriodaphnia dubia used in this study were cultured in 20% dilute mineral water consisting of 20% Perrier® and 80% distilled water, (aerated for 48 h) which was then diluted 1:5 with clean filtered pond water. Both the Perrier® and the pond water supply the necessary nutrients for normal C. dubia growth and reproduction. Organisms were held at 25 °C under a 16 h light:8 h dark photoperiod. C. dubia less than 24 h old were used toxicity tests. Tine feeding regime consisted of 0.1 ml digested cerophyll and TetraMin® and 0.1 ml Selenastrum
(approx. 3 x 106 cells/ml) fed daily to each brood culture and all 15 ml test chambers (Horning and Weber. 1989).

Temperature. pH, dissolved oxygen, and conductivity were measured daily.
At 24 h, test concentrations were renewed with fresh solutions.

Reference substance (positive control):

no

Key result

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

2.3 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

element

Basis for effect:

mortality

Remarks on result:

other: hardness 50 mg/l

Key result

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

5.3 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

element

Basis for effect:

mortality

Remarks on result:

other: hardness 800 mg/l

Validity criteria fulfilled:

not specified

Conclusions:

The 24 h LC50 values based on cobalt ions for C. dubia increased with increasing water hardness, from 2.3 to 5.3 mg/l as the water hardness increased from 50 to 800 mg/l hardness as CaCO3.

Based on molecular weight correction:
LC50, corrected = 349.16 g/mol / 58.9 g/mol x 2.3 mg/L = 13.64 mg/L (lowest value, hardness 50 mg/l as CaCO3)
LC50, corrected = 349.16 g/mol / 58.9 g/mol x 5.3 mg/L = 31.42 mg/L (highest value, hardness 800 mg/l as CaCO3)
The LC50 value for EDTA-CoH2 can be stated as >= 13.64 mg/L.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

GLP compliance:

not specified

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Test temperature:

23 - 27 °C

Details on test conditions:

For each test concentration, three replicates with five daphnia in each were studied. Test vials were kept in the daylight.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

610 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Confidence interval, 95%: 570 - 640 mg/l

Validity criteria fulfilled:

yes

Conclusions:

The LC50, 24 h of edetic acid was found to be 610 mg/l.

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Justification for type of information:

This study is provided to proof edetic acid to be non-ecotoxic towards aquatic invertebrates.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

GLP compliance:

not specified

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Test temperature:

23 - 27 °C

Details on test conditions:

For each test concentration, three replicates with five daphnia in each were studied. Test vials were kept in the daylight.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

610 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Confidence interval, 95%: 570 - 640 mg/l

Validity criteria fulfilled:

yes

Conclusions:

The LC50, 24 h of edetic acid was found to be 610 mg/l.
It can be stated that the LC50 value for edetic acid is much higher than for cobalt salts. Thus the aquatic toxicity of EDTA-CoH2 is determined by the cobalt moiety of the substance only.

Reference 5

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

The study is well-documented by the publication and thus acceptable for assessment.

Qualifier:

no guideline followed

Principles of method if other than guideline:

The study is well-documented by the publication and thus acceptable for assessment.

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna were obtained from wild population. 30 animals were isolated for breeding. 10 clones with the highest number of individuals were chosen. The clone with the highest number of offspring was used to establish a continuous daphnia breed under standardized laboratory conditions.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Hardness:

16 °

Test temperature:

20 - 22 °C

pH:

7.6 - 7.7

Details on test conditions:

day/light: 12 h/ 12 h
feed: daily
change of water twice a week
three replicate tests with 10 daphnia each

Key result

Duration:

24 h

Dose descriptor:

LC0

Effect conc.:

640 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

790 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

24 h

Dose descriptor:

LC100

Effect conc.:

1 250 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

not specified

Conclusions:

The LC50, 24 h of edetic acid was found to be 790 mg/l.

Reference 6

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

This study is provided to proof edetic acid to be non-ecotoxic towards aquatic invertebrates.

Reason / purpose for cross-reference:

read-across source

Qualifier:

no guideline followed

Principles of method if other than guideline:

The study is well-documented by the publication and thus acceptable for assessment.

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna were obtained from wild population. 30 animals were isolated for breeding. 10 clones with the highest number of individuals were chosen. The clone with the highest number of offspring was used to establish a continuous daphnia breed under standardized laboratory conditions.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Hardness:

16 °

Test temperature:

20 - 22 °C

pH:

7.6 - 7.7

Details on test conditions:

day/light: 12 h/ 12 h
feed: daily
change of water twice a week
three replicate tests with 10 daphnia each

Key result

Duration:

24 h

Dose descriptor:

LC0

Effect conc.:

640 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

790 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

24 h

Dose descriptor:

LC100

Effect conc.:

1 250 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

not specified

Conclusions:

The LC50, 24 h of edetic acid was found to be 790 mg/l.
It can be stated that the LC50 value for edetic acid is much higher than for cobalt salts. Thus the aquatic toxicity of EDTA-CoH2 is determined by the cobalt moiety of the substance only.

Description of key information

It can be stated that the LC50 value for aquatic invertebrates for edetic acid is much higher than for cobalt salts. Thus, the aquatic toxicity of EDTA-CoH2 is determined by the cobalt moiety of the substance only.

Based on the LC value for cobalt salt and molecular weight correction the LC50 value for EDTA-CoH2 can be stated as >= 13.64 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

13.64 mg/L