(2-hydroxy-1,1-dimethylethyl)ammonium toluene-4-sulphonate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples were taken from the control and the 100 mg/L test group from the bulk test preparation at 0 hours and from the pooled replicates at 48 hours for quantitative analysis. All samples were stored frozen prior to analysis. Duplicate samples were taken at 0 and 48 hours and stored frozen for further analysis if necessary.

Vehicle:

no

Details on test solutions:

Reconstituted water (Elendt M7 medium) used for both the range-finding and definitive tests.
Reconstituted Water – Elendt M7 Medium
Ingredient
Final Concentration (mg/L)
H3BO3
0.715
MnCl2.4H2O
0.090
LiCl
0.077
RbCl
0.018
SrCl2.6H2O
0.038
NaBr
0.004
Na2MoO4.2H2O
0.016
CuCl2.2H2O
0.004
ZnCl2
0.013
CoCl2.6H2O
0.010
KI
0.0033
Na2SeO3
0.0022
NH4VO3
0.00058
Na2EDTA.2H2O
0.625
FeSO4.7H2O
0.249
CaCl2.2H2O
293.8
NaHCO3
64.8
MgSO4.7H2O
123.3
Na2SiO3.9H2O
10
KCl
5.8
NaNO3
0.274
K2HPO4
0.184
KH2PO4
0.143
Thiamine hydrochloride
0.075
Cyanocobalamine (vitamin B12)
0.0010
D(+) biotin (vitamin H)
0.00075

Test organisms (species):

Daphnia magna

Details on test organisms:

The test was carried out using 1st instar Daphnia magna derived from in-house laboratory cultures.
Adult daphnia were maintained in 150 mL glass beakers containing Elendt M7 medium (see Annex 1) in a temperature controlled room maintaining the water temperature at 18 to 22 °C. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods. Each culture was fed daily with a mixture of algal suspension (Desmodesmus subspicatus) and Tetramin® flake food suspension. Culture conditions ensured that reproduction was by parthenogenesis. Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old. These young were removed from the cultures and used for testing. The diet and diluent water are considered not to contain any contaminant that would affect the integrity or outcome of the study.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

No

Hardness:

See composition under Details on test solution

Test temperature:

18-22 C

pH:

7.9

Dissolved oxygen:

> 3 mg/l

Nominal and measured concentrations:

Nominal 100 mg/l
Measures 99 mg/l at 24 h and 48 h

Details on test conditions:

Adult daphnia were maintained in 150 mL glass beakers containing Elendt M7 medium in a temperature controlled room maintaining the water temperature at 18 to 22 °C. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods. Each culture was fed daily with a mixture of algal suspension (Desmodesmus subspicatus) and Tetramin® flake food suspension. Culture conditions ensured that reproduction was by parthenogenesis. Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old. These young were removed from the cultures and used for testing. The diet and diluent water are considered not to contain any contaminant that would affect the integrity or outcome of the study.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No immobilization was observed at the test concentrations of 0.10, 1.0, 10 and 100 mg/L.
Based on this information, a single test concentration of four replicates, of 100 mg/L was selected for the definitive test. This experimental design conforms to a "Limit test" to confirm that at the maximum test concentration given in the OECD/EC Test Guidelines, no immobilization or adverse reactions to exposure were observed.
Chemical analysis of the 100 mg/L test preparations at 0 and 48 hours (see Annex 3) showed near nominal concentrations were obtained indicating that the test item was stable over the test duration

Imobilization Data
There was no immobilization in 20 daphnids exposed to a test concentration of 100 mg/L for a period of 48 hours.
It was considered unnecessary and unrealistic to test at concentrations in excess of 100 mg/L.
Sub-Lethal Effects
A single daphnid in the 100 mg/L test preparation was observed to have reduced mobility at 48 hours.
Validation Criteria
The test was considered to be valid given that none of the control daphnids showed immobilization or other signs of disease or stress and that the oxygen concentration at the end of the test was equal to or greater than 3 mg/L in the control and test vessels.
Water Quality Criteria
The results of the water quality measurements are given in Table 3. Temperature was maintained at 19 °C to 22 °C throughout the test, while there were no treatment related differences for oxygen concentration or pH.
Throughout the test the light intensity was observed to be in the range 637 to 648 Lux.
Observations on Test Item Solubility
At the start and throughout the test all control and test solutions were observed to be clear colorless solutions.

Results with reference substance (positive control):

The results from the positive control with potassium dichromate were within the normal range for this reference item.
24 h EC50=1.3 ml/l
48 h EC50=1.2 mg/l

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of the test item to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-Hour EC50 value of greater than 100 mg/L. The No Observed Effect Concentration was 100 mg/L.

Executive summary:

The acute toxicity of the test item to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-Hour EC50 value of greater than 100 mg/L. The No Observed Effect Concentration was 100 mg/L.

Description of key information

The acute toxicity of the test item to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-Hour EC50 value of greater than 100 mg/L. The No Observed Effect Concentration was 100 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

100 mg/L