2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol

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:

1984-09-03 to 1984-09-07

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Non-GLP guideline study according to OECD 203. Excessive concentration of emulsifier allowed testing of concentrations well above the limit of water solubility of 0.04 mg/L at 20°C. Considered acceptable because no effects observed up to the highest nominal test concentration of 100 mg/L.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

, test performed as limit test with concentration 100 mg/L nominal. Highest vehicle concentration 891 mg/L.

GLP compliance:

no

Analytical monitoring:

yes

Details on sampling:

Samples for analysis taken after 0h and 96h exposure

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 100 g of the test substance were dissolved in Tetrrahydrofuran (THF): 4000 mg Arkopal N150 and made up to 1000 mL with THF
- Controls: Blank control with test medium only and vehicle control with 887 mg THF; 4 mg Arkopal N150 per liter water in the concentration used for the test concentration
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Tetrahydrofuran and Arkopal N150
- Stock solution: 100 g of the test substance were dissolved in Tetrrahydrofuran (THF): 4000 mg Arkopal N150 and made up to 1000 mL with THF
- Evidence of undissolved material (e.g. precipitate, surface film, etc): Yes. Precipitation was observed after 24h exposure.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Source: West Aquarium / D-3422 Bad Lauterberg
- Length at study initiation (length definition, mean, range and SD): 26 mm (22-28 mm)
- Weight at study initiation (mean and range, SD): 0.14 g (0.05-0.19 g)
- Loading: 0.09 g/L
- Feeding during test: None

ACCLIMATION
- Adaption: 24 hours / no food 24 hours prior to exposure

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

170 mg CaCO3/L

Test temperature:

22 ± 1°C

pH:

7.9 - 8.2

Dissolved oxygen:

80 - 103%

Nominal and measured concentrations:

Nominal: 100 mg/L
Measured: 67 mg/L (arithmetic mean)

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass aquaria of 20 liters filled with 15 liters (36/22/25 cm)
- Aeration: none
- 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: 0.09 g/l

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dechlorinated tap water (carbon filter)
- Intervals of water quality measurement: Daily

OTHER TEST CONDITIONS
- Photoperiod: Fluorescent light, 16 hours daily

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality, Symptoms

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

> 67 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 67 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

> 67 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: slight effects on swimming behaviour in test item treatment group after 48, 72 and 96 h
- Mortality of control: None
- Other adverse effects control: None
- Abnormal responses: None
- Any observations (e.g. precipitation): Initially the test substance appeared homogeneously distributed. Precipitations were observed after 24 h exposure.
- Effect concentrations exceeding solubility of substance in test medium: Yes

Description of key information

With high probability acutely not harmful to fish. No toxic effects occur within the range of solubility

Additional information

The study was performed according to OECD guideline no. 203 (1984) as a limit test with a nominal concentration of 100 mg/L (measured concentration: 67 mg/L) under static conditions. The LC₀ and the LC₅₀ (96h) in Danio rerio are both higher than 67 mg/L, according to the measured concentrations at the beginning and at the end of the study (average of the two values). The test compound concentration did not change during the test period. The substance was mixed with tetrahydrofuran to make a stock solution. The test substance was present at least partially as a suspension.

No mortality, but slight effects on swimming behaviour were observed after 24 to 96 hours.

The effect concentration is well above the solubility limit of the test substance (water solubility < 0.005 mg/L at 20°C, see chapter 4.8 in IUCLID). Therefore, they represent a worst case assumption where water solubility is achieved by excessive use of solvent. In conclusion, the substance shows no effect in the range of water solubility.