Magnesium octadecylbenzenesulphonate

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:

22 July 2014-24 July 2014

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

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Guidance document on aquatic toxicity testing of difficult substances and mixtures, OECD series on testing and assessment number 23, December 14, 2000.

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples for analysis were taken from all test concentrations and the control according to the schedule below. In addition, the filter used to prepare the limit concentration was retained for possible analysis of the residue.

Frequency: at t=0 h and t=48 h
Volume: 2.0 ml from the approximate centre of the test vessels
Storage : Not applicable, samples were analysed on the day of sampling.

At the end of the exposure period, the replicates were pooled at each concentration before sampling.

Vehicle:

no

Details on test solutions:

The batch of EXP1313100 tested was a brown solid that was not completely soluble in test medium at the loading rates initially prepared.

All test solutions were prepared separately. Various loading rates of the test substance were added to the test medium applying two days of magnetic stirring in order to reach maximum solubility. The resulting aqueous mixtures were filtered through a 0.45 µm membrane filter (Whatman) where after the clear and colourless Water Accommodated Fractions (WAFs) were used for testing.

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna (Crustacea, Cladocera) (Straus, 1820), at least third generation, obtained by acyclical parthenogenesis under specified breeding conditions.
Source: In-house laboratory culture with a known history.
Age at study initiation: For the test selection of young daphnids with an age of < 24 hours, from parental daphnids of more than two weeks old.
Method of Breeding:
With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 10 litres of medium in an all-glass culture vessel.
Medium: M7, as prescribed by Dr. Elendt-Schneider (Elendt, B.-P., 1990: Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus. Protoplasma 154, 25-33).
Feeding:Daily, a suspension of fresh water algae.
Validity of batch: Daphnids originated from a healthy stock, 2nd to 5th brood, showing no signs of stress such as mortality >20%, presence of males, ephippia or discoloured animals and there was no delay in the production of the first brood.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

The hardness: 180 mg/L expressed as CaCO3

Test temperature:

Start of the test: between 20 and 21°C
During the test continuosly measured: between 20 and 22°C

pH:

Between 7.7 and 8.1

Dissolved oxygen:

between 8.7 and 8.9

Nominal and measured concentrations:

Nominal concentrations: WAF's prepared at loading rates of 1.0, 10 and 100 mg/L.
Measured concentration: The initial concentrations in the WAFs prepared at loading rates of 1.0, 10 and 100 mg/L were 0.029, 0.60 and 0.21 mg/L. These concentrations remained stable during the test period (88-98% of initial at the end of the test). The concentrations obtained in the WAFs prepared at loading rates of 10 and 100 mg/L indicated that the maximum solubility in test medium was exceeded at these loading rates.

Details on test conditions:

TESTSYTEM:
Test vessels:100 mL, all-glass.
No. of replicates: per concentration:4 for thecontrol and the highest concentration and 2 for the lower concentrations.
Number of daphnids : 20 each for the control and the WAF prepared at 100 mg/L, 10 each for the remaining WAFs.
Loading: 5 per vessel containing 80 mL of test solution.

TESTMEDIUM/WATER PARAMETERS
Medium: Adjusted ISO medium: the following chemicals (analytical grade) are dissolved in tap water purified by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands):
Macro salts:
CaCl2.2H2O: 211.5 mg/L
MgSO4.7H2O: 88.8 mg/L
NaHCO3: 46.7 mg/L
KCl : 4.2 mg/L
The hardness: 180 mg/l expressed as CaCO3 and the pH: 7.7 ±after aeration.
- Culture medium different from test medium: yes, for culturing M7 medium is used.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours photoperiod daily.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : EC50 t=24, 48 h.
TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10
- Test concentrations: control and WAFs prepared at loading rates of 1.0, 10 and 100 mg/L.

Reference substance (positive control):

yes

Remarks:

potassium dichromate (K2Cr2O7)

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 0.21 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.21 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Behavioural abnormalities: no
- Immobility of control: no immobility was observed.
- Other adverse effects control: no

Results with reference substance (positive control):

The 24h-EC50 was 0.70 mg/L with a 95% confidence interval between 0.62 and 0.80 mg/L.
The 48h-EC50 was 0.41 mg/L with a 95% confidence interval between 0.36 and 0.47 mg/L.

Reported statistics and error estimates:

Calculation of EC50
The 24 and 48h-EC50 values could not be determined because the observed effects were below 50%.

Validity criteria fulfilled:

yes

Conclusions:

No effect on mobility was recorded at any of the loading rates of EXP1313100 tested.
The 48h-EL*50 was above a loading rate of 100 mg EXP1313100 per litre. The concentration of EXP1313100 in the WAF prepared at a loading rate of 100 mg/L was determined to be 0.21 mg/L based on the initial exposure concentration. This concentration was considered to be above the maximum solubility of EXP1313100 in the test medium.

*EL = effective loading rate

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:

22 July 2014-24 July 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Guidance document on aquatic toxicity testing of difficult substances and mixtures, OECD series on testing and assessment number 23, December 14, 2000.

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples for analysis were taken from all test concentrations and the control according to the schedule below. In addition, the filter used to prepare the limit concentration was retained for possible analysis of the residue.

Frequency: at t=0 h and t=48 h
Volume: 2.0 ml from the approximate centre of the test vessels
Storage : Not applicable, samples were analysed on the day of sampling.

At the end of the exposure period, the replicates were pooled at each concentration before sampling.

Vehicle:

no

Details on test solutions:

The batch of EXP1313100 tested was a brown solid that was not completely soluble in test medium at the loading rates initially prepared.

All test solutions were prepared separately. Various loading rates of the test substance were added to the test medium applying two days of magnetic stirring in order to reach maximum solubility. The resulting aqueous mixtures were filtered through a 0.45 µm membrane filter (Whatman) where after the clear and colourless Water Accommodated Fractions (WAFs) were used for testing.

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna (Crustacea, Cladocera) (Straus, 1820), at least third generation, obtained by acyclical parthenogenesis under specified breeding conditions.
Source: In-house laboratory culture with a known history.
Age at study initiation: For the test selection of young daphnids with an age of < 24 hours, from parental daphnids of more than two weeks old.
Method of Breeding:
With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 10 litres of medium in an all-glass culture vessel.
Medium: M7, as prescribed by Dr. Elendt-Schneider (Elendt, B.-P., 1990: Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus. Protoplasma 154, 25-33).
Feeding:Daily, a suspension of fresh water algae.
Validity of batch: Daphnids originated from a healthy stock, 2nd to 5th brood, showing no signs of stress such as mortality >20%, presence of males, ephippia or discoloured animals and there was no delay in the production of the first brood.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

The hardness: 180 mg/L expressed as CaCO3

Test temperature:

Start of the test: between 20 and 21°C
During the test continuosly measured: between 20 and 22°C

pH:

Between 7.7 and 8.1

Dissolved oxygen:

between 8.7 and 8.9

Nominal and measured concentrations:

Nominal concentrations: WAF's prepared at loading rates of 1.0, 10 and 100 mg/L.
Measured concentration: The initial concentrations in the WAFs prepared at loading rates of 1.0, 10 and 100 mg/L were 0.029, 0.60 and 0.21 mg/L. These concentrations remained stable during the test period (88-98% of initial at the end of the test). The concentrations obtained in the WAFs prepared at loading rates of 10 and 100 mg/L indicated that the maximum solubility in test medium was exceeded at these loading rates.

Details on test conditions:

TESTSYTEM:
Test vessels:100 mL, all-glass.
No. of replicates: per concentration:4 for thecontrol and the highest concentration and 2 for the lower concentrations.
Number of daphnids : 20 each for the control and the WAF prepared at 100 mg/L, 10 each for the remaining WAFs.
Loading: 5 per vessel containing 80 mL of test solution.

TESTMEDIUM/WATER PARAMETERS
Medium: Adjusted ISO medium: the following chemicals (analytical grade) are dissolved in tap water purified by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands):
Macro salts:
CaCl2.2H2O: 211.5 mg/L
MgSO4.7H2O: 88.8 mg/L
NaHCO3: 46.7 mg/L
KCl : 4.2 mg/L
The hardness: 180 mg/l expressed as CaCO3 and the pH: 7.7 ±after aeration.
- Culture medium different from test medium: yes, for culturing M7 medium is used.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours photoperiod daily.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : EC50 t=24, 48 h.
TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10
- Test concentrations: control and WAFs prepared at loading rates of 1.0, 10 and 100 mg/L.

Reference substance (positive control):

yes

Remarks:

potassium dichromate (K2Cr2O7)

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 0.21 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.21 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Behavioural abnormalities: no
- Immobility of control: no immobility was observed.
- Other adverse effects control: no

Results with reference substance (positive control):

The 24h-EC50 was 0.70 mg/L with a 95% confidence interval between 0.62 and 0.80 mg/L.
The 48h-EC50 was 0.41 mg/L with a 95% confidence interval between 0.36 and 0.47 mg/L.

Reported statistics and error estimates:

Calculation of EC50
The 24 and 48h-EC50 values could not be determined because the observed effects were below 50%.

Validity criteria fulfilled:

yes

Conclusions:

No effect on mobility was recorded at any of the loading rates of EXP1313100 tested.
The 48h-EL*50 was above a loading rate of 100 mg EXP1313100 per litre. The concentration of EXP1313100 in the WAF prepared at a loading rate of 100 mg/L was determined to be 0.21 mg/L based on the initial exposure concentration. This concentration was considered to be above the maximum solubility of EXP1313100 in the test medium.

*EL = effective loading rate

Description of key information

No effect on mobility was recorded at any of the loading rates. The 48h-EL50 was above a loading rate of 100 mg/L.