4-mesyl-2-nitrotoluene

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 May 1999 to 14 May 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant, guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

One control was ouside the range 50 ± 10 mm in length at test termination. This is considered not to impact on the validity of the test

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Samples were taken from the exposure concentrations and control.
- Sampling method: Samples were taken from the test medium at the start of the test, after 48 hours and after 96 hours. At the same times samples were also taken from the controls. Samples were taken from the approximate centre of the aquarium.
- Sample storage conditions before analysis: Not reported

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method:The test solutions were prepared by the direct addition of the required amounts of the test substance to each exposure vessel and thoroughly stirring for 24 hours.
- Controls: Yes, a single blank control of test water
- Evidence of undissolved material (e.g. precipitate, surface film, etc): A few white particles.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Strain: Not reported
- Source: Houghton Springs Fish Farm, Winterbourne Houghton, Blandford Forum, Dorset, DT11 0PD
- Age at study initiation (mean and range, SD): Not reported
- Control fish length at study termination: 39 - 52 mm, mean: 44 mm
- Control fish weight at study termination: 0.74 - 1.89 g, mean: 1.22 g
- Method of breeding: Not reported
- Feeding during test: No feeding from 24 hours prior to test


ACCLIMATION
- Acclimation period: 7 weeks
- Acclimation conditions (same as test or not): same as test, but with feeding and single large tank.
- Type and amount of food: Keystart 1200®
- Feeding frequency: Fed daily
- Health during acclimation (any mortality observed): No evidence of disease.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

44.0 mg/L as CaCO3

Test temperature:

14.2 ± 15.1°C measured daily

pH:

7.24 - 7.57 measured daily

Dissolved oxygen:

9.23 - 10.27 mg O2/L, measured daily

Nominal and measured concentrations:

See Table 1. Measured concentrations were in the range of 99 - 110 % of nominal, so results are reported as nominal concentrations

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: Borosilicate glass vessels, 400 mm x 280 mm x 280 mm, max capacity 27.5 L, working volume 20 L.
- Aeration: Gentle aeration throughout test..
- Renewal rate of test solution (frequency/flow rate): Static test
- No. of organisms per vessel: 10 fish
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): No vehicle control used
- Biomass loading rate: 0.61 g fish (wet weight)/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water, passed through activated carbon, coarsely filtered, dechlorinated with sodium thiosulphate and salts added (as required) to maintain minimum hardness levels. Total hardness reduced by ion exchange
- Total organic carbon: Not reported
- Particulate matter: Not reported
- Metals: Not reported
- Pesticides: Not reported
- Chlorine: Free residual: <2 µg/L, Combined residual: <2 µg/L
- Alkalinity: 22.6 mg/L as CaCO3
- Ca/mg ratio: Not reported
- Conductivity: 204 µS cm-1 at 25°C
- Culture medium different from test medium: No
- Intervals of water quality measurement: Not reported


OTHER TEST CONDITIONS
- Adjustment of pH: None
- Photoperiod: 16L:8D with a 20 minute transition period
- Light intensity: Not reported


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Fish were observed after 24, 48, 72 and 96 hours for mortality and visible abnormalities.


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Test concentrations: 10, 18, 32, 56, 100 mg/L

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

70 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CI: 57-94 mg/L

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

61 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CI: 52-74 mg/L

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

59 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CI: 49-70 mg/L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: all symptoms observed

Details on results:

- Behavioural abnormalities: Fish showed the following abnormailities: Quiescence, sounding, loss of balance, cessation of swimming .
- Observations on body length and weight: Not reported
- Other biological observations: Fish showed the following abnormailities: Weakness, dark discolouration.
- Mortality of control: No mortality in controls
- Other adverse effects control: No other adverse effects in controls
- Abnormal responses: No abnormal responses observed
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: Not applicable as test concentrations measured
- Effect concentrations exceeding solubility of substance in test medium: No

Reported statistics and error estimates:

LC50s and 95% confidence intervals calculated by moving average angle

Sublethal observations / clinical signs:

Table 2 Effects of the test subsance on the survival of Oncorhynchus mykiss

Nominal concentration (mg/L)	Cumulative percentage mortality observed
	24 hours	48 hours	72 hours	96 hours
Dilution water control	0	0	0	0
10	0	0	10	10
18	0	0	0	0
32	0	0	0	0
56	20	20	30	40
100	60	90	100	100
LC50(mg/L)	not calcuated	70	61	59
NOEC (mg/L) (all symptoms)	not calcuated	not calcuated	not calcuated	18

Validity criteria fulfilled:

yes

Conclusions:

Based on nominal concentration, the 96-hour LC50 for rainbow trout (Oncorhynchus mykiss) was 59 mg/L and the 96-hour NOEC was 18 mg/L.

Executive summary:

The acute toxicity of the test substance to rainbow trout (Oncorhynchus mykiss) was determined. In accordance with the guideline fish were exposed to a test item concentrations of 10, 18, 32, 56 and 100 mg/L, alongside a dilution water control. Based on nominal concentrations, the 96-hour LC₅₀ was 59 mg/L and the 96 -hour NOEC was 18 mg/L.

Description of key information

LC50=59 mg/L, 96h, Oncorhynchus mykiss, static, OECD 203, Magor 1999

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

59 mg/L

Additional information

The acute toxicity of the test substance to rainbow trout (Oncorhynchus mykiss) was determined. In accordance with the guideline, fish were exposed to test item concentrations of 10, 18, 32, 56 and 100 mg/L, alongside a dilution water control. Based on nominal concentrations, the 96-hour LC50 was 59 mg/L and the 96-hour NOEC was 18 mg/L. The study is considered to be reliable and adequate for the purposes of risk assessment, classification and labelling.