4-mesyl-2-nitrotoluene

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

Study period:

4 May to 6 May 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant, 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

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Samples were taken from each of the exposure concentrations and the control
- Sampling method: At the start of the test the excess test solutions were sampled. At the end of the test samples were taken from each of the exposure concentrations and the control.
- Sample storage conditions before analysis: Not reported

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A nominal stock solution of the test substance of 180 mg/L was prepared by dissolving 0.3601 mg of test item in 2 L of test water by stirring for 24 hours.
- Controls: Yes, a blank control of test water
- Evidence of undissolved material (e.g. precipitate, surface film, etc): None

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: Not reported
- Source: Continuous laboratory culture
- Age at study initiation (mean and range, SD): <24 hours old
- Weight at study initiation (mean and range, SD): Not reported
- Length at study initiation (length definition, mean, range and SD): Not reported
- Method of breeding: Diploid Parthenogenesis
- Feeding during test: None

ACCLIMATION
- Acclimation period: None

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

205.3 mg/L as CaCO3

Test temperature:

20 ± 1 °C

pH:

7.59 - 8.01 measured at start and end of test

Dissolved oxygen:

8.8 - 9.2 mg O2/L measured at start and end of test

Nominal and measured concentrations:

See Table 1. Measured concentrations ranged from 100 to 106% of nominal concentrations, therefore results are reported as nominal concentrations

Details on test conditions:

TEST SYSTEM
- Test vessel: Borosilicate glass beakers
- Material, size, headspace, fill volume: 250 mL glass beakers filled with 200 mL test solution, loose fitting glass lids.
- Aeration: None
- Type of flow-through (e.g. peristaltic or proportional diluter): Static, none used
- Renewal rate of test solution (frequency/flow rate): Static test
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 25 organisms/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt's M4 Daphnia medium (Ref 4)
- Total organic carbon: 2.071 mg/L (nonpurgeable organic carbon)
- Particulate matter: Not reported
- Metals: Fe: 0.2 mg/L, Mn: 0.1 mg/L, Li: 0.05 mg/L, Rb: 0.05 mg/L, Sr: 0.05 mg/L, Mo: 0.025 mg/L, Br: 0.0125 mg/L, Cu: 0.0063 mg/L, Zn: 0.0063 mg/L, Co: 0.0025 mg/L, V: 0.0003 mg/L. All values nominal.
- Pesticides: Not reported
- Chlorine: Not reported
- Alkalinity: 40.6
- Ca/Mg ratio: Not reported
- Conductivity: Not reported
- Culture medium different from test medium: No
- Intervals of water quality measurement: Not reported

OTHER TEST CONDITIONS
- Adjustment of pH: Not reported
- Photoperiod: 16 hour light, 8 hour dark cycle with 20 min transition period
- Light intensity: Not reported

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Daphnia were observed after 24 and 48 hours for immobility and visible abnormalities.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Test concentrations: 18, 32, 56, 100, 180 mg/L

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

180 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: immobility

Remarks on result:

other: 95% CI: 160 - 240 mg/L

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

120 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: immobility

Remarks on result:

other: 95% CI: 100 - 140 mg/L

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

56 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: immobility

Details on results:

- Behavioural abnormalities: No abnormalities reported
- Observations on body length and weight: Not reported
- Other biological observations: None
- Mortality of control: No mortality in controls
- Other adverse effects control: No other adverse effects in controls
- Abnormal responses: No abnormal responses in controls
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No
- Effect concentrations exceeding solubility of substance in test medium: No

Reported statistics and error estimates:

EC50 values and 95% Confidence Intervals calculated by Moving average angle

Table 2: Effects on the mobility of Daphnia magna

Nominal concentration (mg/L)	Immobilised daphnids after 24 hours		Immobilised daphnids after 48 hours
	Number	%	Number	%
Dilution water control	0	0	0	0
18	0	0	0	0
32	0	0	0	0
56	0	0	0	0
100	0	0	6	30
180	10	50	18	90
EC50(mg/L)	180		120
NOEC (mg/L)	100		56

Validity criteria fulfilled:

yes

Conclusions:

Based on nominal concentration, the 48 hour EC50 to Daphnia magna was 120 mg/L and the 48 hour NOEC was 56 mg /L.

Executive summary:

The acute toxicity of the test substance to daphnia magna was determined. In accordance with the guideline, daphnia were exposed to test item concentrations of 18, 32, 56, 100 and 180 mg/L, alongside a dilution water control. Based on nominal concentrations the 48 hour EC₅₀was 120 mg/L and the 48 hour NOEC was 56 mg/L.

Description of key information

EC50=120 mg/L, 48h, Daphnia magna, static, OECD 202, Magor 1999

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

120 mg/L

Additional information

The acute toxicity of the test substance to water flea (Daphnia magna) was determined. In accordance with the guideline, daphnids were exposed to test item concentrations of 18, 32, 56, 100 and 180 mg/L, alongside a dilution water control. Based on nominal concentrations the 48 hour EC50 was 120 mg/L and the 48 hour NOEC was 56 mg/L. The study is considered to be reliable and adequate for the purposes of risk assessment, classification and labelling.