A mixture of: isomers of 2-(2H-benzotriazol-2-yl)-4-methyl-(n)-dodecylphenol; isomers of 2-(2H-benzotriazol-2-yl)-4-methyl-(n)-tetracosylphenol; isomers of 2-(2H-benzotriazol-2-yl)-4-methyl-5,6-didodecyl-phenol. n=5 or 6

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20.05. - 13.06.2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD guideline study, GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

adopted 1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

adopted 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

For the analysis of the actual test item concentrations the following samples were taken:

Just before test start:
- duplicate samples from the test medium (without daphnids)
- duplicate samples from the control (without daphnids)

After 48 hours (stability samples):
- duplicate samples from the test medium (without daphnids)
- duplicate samples from the control (without daphnids)

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
An undiluted filtrate of a supersaturated dispersion with the maximum concentration of dissolved test item was used as the only test concentration.
- Controls: test water without test item

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: Clone 5
- Source: bred in the laboratories of RCC
- Age at study initiation: 6-24 hrs
- Method of breeding: in reconstituted water of the quality identical to the water quality used in the tests (regarding pH, main ions and total hardness) and under temperature and light conditions identical to those of the tests
- Feeding during test: no

ACCLIMATION
- Acclimation period: no

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

2.5 mmol/L (=250.0 mg/L) as CaCO3

Test temperature:

20 °C

pH:

between 7.9 and 8.0 during test

Dissolved oxygen:

between 8.2 mg/L and 8.4 mg/L during test

Nominal and measured concentrations:

nominal: 100 mg/L (undiluted filtrate, loading rate)
measured: < 0.005 mg/L (calculated as the average over all measurements in the undiluted filtrate during the test period).

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL glass beaker
- Type: beakers covered with glass plates
- Aeration: no
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: < 1 Daphnia/ 2 mL test solution

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted test water: analytical grade salts were dissolved in purified water.
- Culture medium different from test medium: no
- Intervals of water quality measurement:
At the start and at the end of the test, the pH-values, the oxygen concentrations and the water temperature were determined In the single test concentration and the control. The appearance of the test medium was recorded at the start of the test and after 24 and 48 hours.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16-hour light to 8-hour darkness photoperiod with a 30 minute transition period
- Light intensity: between 550 and 685 Lux

EFFECT PARAMETERS MEASURED:
The immobility of the daphnids was determined by visual control after 24 and 48 hours of exposure. Those organisms not able to swim within 15 seconds after gentle agitation of the test beaker were considered to be immobile. The EC50 and the EC100 could not be calculated due to the absence of a toxic effect of the test item in this test at the tested concentrations. The NOEC, EC0 were determined directly from the raw data.

TEST CONCENTRATIONS
- Range finding study
The test concentrations were based on the results of a range-finding test and on results of a pre-experiment to the solubility of the test item (without GLP).

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

> 0.005 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.005 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: no
- Observations on body length and weight: no data
- Other biological observations: no
- Mortality of control: no
- Other adverse effects control: no
- Abnormal responses: no

Results with reference substance (positive control):

For evaluation of the quality of the Daphnia magna clone and of experimental conditions, potassium dichromate is tested as a positive control at least once a year to demonstrate satisfactory test conditions. The results with the reference substance are not reported.

Reported statistics and error estimates:

Not performed.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Study period:

19. - 20.12.1985

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: OECD guideline study, none GLP. In deviation from the current OECD guideline, the test duration was 24 hrs and not 48 hrs. Furthermore, high concentrations of an emulsifier were used in the preparation of the test medium.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

adopted 1984

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

yes

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

24 h

Nominal and measured concentrations:

Nominal: 1.8; 3.2; 5.8; 10; 18; 32; 58 mg/L
Measured: 1; 1.7; 2.9; 7.1; 19.5; 22.3; 35.1 mg/L

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

4.1 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 3.0 - 6.7 mg/L

Description of key information

There is a high probability that the product is not acutely harmful to aquatic invertebrates.

Additional information

Two studies on the toxicity to aquatic invertebrates are available. One of these studies (Ciba-Geigy 1986) is not regarded as valid due to the shortened exposure time of only 24 h and the use of high concentrations of emulsifier.

The valid study (RCC 2002) was conducted according to test guideline 92/69/EWG, C.2 (equivalent to OECD 202) under consideration of the OECD guidance document on aquatic toxicity testing of difficult substances (2000). This study did not reveal any toxicity in the range of water solubility. The 48-hour NOEC and the 48-hour EC0 of the test item to Daphnia magna were determined at a nominal concentration of 100 mg/L. The 48 -hour EC50 and the 48-hour EC100 were determined to be greater than 100 mg/L nominal concentration.