2,6-di-tert-butyl-4-nonylphenol

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Deviations:

not specified

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

yes

Remarks:

7% v/v Tween 80 in dimethylformamide

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The concentration of 10 mg/L was the highest attainable concentration that could be prepared due to the limited water solubility of the test material in water and having due regard to the amout of auxiliary solvent permitted in the study under OECD Guidelines. Other conbinations of the various recognised auxiliary solvents and mixtures of Tween 80(up to 10% Tween 80 in solvent) were used during the range finder. However, the combination of 7% Tween 80 in dimethylformamide was found to give the best testable dispersion of the test material in water.
- Controls: blank control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): % Tween 80 in dimethylformamide
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): not reported but is is mentioned that the concentrations given in the OECD Guideline were not exceeded.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Source: Donninton Fish Farm. Upper Swll, Gloucestershire, U.K.
- Length at study initiation (length definition, mean, range and SD): 4.2 +/- 0-4 cm
- Weight at study initiation (mean and range, SD): 0.93 +/- 0.20 g

ACCLIMATION
- Health during acclimation (any mortality observed): no mortality during 7 days prior to test start

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

approximately 100 mg/L as CaCO3

Test temperature:

14°C

Nominal and measured concentrations:

control, solvent control, and 10 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: not specified
- Material, size, headspace, fill volume: 20 L
- Aeration: yes
- Renewal rate of test solution (frequency/flow rate): daily
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates):1
- No. of vessels per vehicle control (replicates):1
- Biomass loading rate: 0.47 g/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated tap water

OTHER TEST CONDITIONS
- Adjustment of pH: not reported
- Photoperiod: not reported

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : LC50 at 3, 6, 24, 48, 72 and 96 hours

TEST CONCENTRATIONS
- Spacing factor for test concentrations for range finder: control, solvent control, and nominal 0.1, 1 and 10 mg/L, no mortality observed
- Justification for using less concentrations than requested by guideline:

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: no adverse findings
- Mortality of control: none
- Other adverse effects control: none
- Abnormal responses: none
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: not reported - Effect concentrations exceeding solubility of substance in test medium: not reported

Reported statistics and error estimates:

not needed since no adverse effects observed

Validity criteria fulfilled:

yes

Conclusions:

96h-LC50: >10 mg/L

Executive summary:

In the semi-static test with daily renewal from Wetton (1995) with Isonox 232, the LC50 for rainbow trout was determined in a limit test to be > 10 mg/L. Doseverification analysis was not performed. The study is considered reliable with restrictions for the risk assessment.

Description of key information

96h-LC50: >10 mg/L

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

10 mg/L

Additional information

In the semi-static test with daily renewal from Wetton (1995) with Isonox 232, the LC50 for rainbow trout was determined in a limit test to be > 10 mg/L. Doseverification analysis was not performed. The study is considered reliable with restrictions for the risk assessment.