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

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:

from 2012-08-16 to 2012-09-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study according to guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

,2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: In the definitive test Daphnia magna was exposed in one concentration: 100.0 mg/L WAF for 48 h in static design.
- Sampling method: The test was performed using Elendt M7 medium for culturing and as diluent for preparing the test concentrations.
- The medium was aerated prior test initiation.
- The test was conducted in glass beakers of 150 mL capacity covered with transparent lids in order to minimize evaporation and to prevent
accidental contamination.
- The volume of the test concentration and test medium for the control in every replicate was 100 mL. Five individuals of Daphnia magna were used in each replicate (20 mL of test solution per daphnid in accordance with the OECD Guideline which requires at least 2 mL).
- The test concentration and control was tested in four replicates.
- The time of exposure was 48 hours.
- During the test daphnids were not fed and the temperature of solutions was constantly recorded.

Vehicle:

no

Details on test solutions:

- In order to determine the concentrations of test item in the definitive test, the preliminary (non-GLP) range finding static tests were performed.
- In the definitive test the test item was used in one concentration of 100 mg/L WAF. The test concentration was prepared by weighing test item and mixing with Elendt M7 medium.
- The test concentration was ultrasonicated for 15 min at 40°C temperature.
- The test concentration was turbid, heterogeneous and particles of the test item were visible on the surface and bottom of flask. The test contraction and the control were mixed by mechanic shaker at room temperature. After 24 h of mixing particles of the test item were visible on the surface and on the bottom.

- The test concentration and control were filtrated through conditioned nitrocellulose membranes. The filtrates were clear and homogeneous. These filtrates were Water Accommodated Fraction (WAF) used for exposure.

- Each filtrate was poured into four replicates per 100 mL each. The glass beakers of 150 mL capacity were used. Test vessels were covered with transparent plastic lids in order to minimize evaporation and to prevent accidental contamination. In each beaker five young Daphnia magna were exposed to the test item for 48 h. The test was of static design.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: Daphnia magna Straus
- Source: Originates from the standard laboratory culture maintained in the Institute of Industrial Organic Chemistry, Branch Pszczyna, Department of Ecotoxicology, Laboratory of Aquatic Toxicology.
- Age at study initiation (mean and range, SD): Only organisms up to 24 h old (not first brood progeny) and in good physiological condition were used in the experiments.
- Method of breeding: Daphnia magna reproduce parthenogenetically, therefore in each beaker young daphnids were produced. The young (less than 24 h old) Daphnia magna, progeny of 21 – 25 days old parent, were used in the tests.
- Feeding: The daphnids were fed with Pseudokirchneriella subcapitata algae suspension originating from the culture at the
Laboratory of Aquatic Toxicology. Group B vitamins and micronutrients necessary for proper growth were supplied with lyophilized Spirulin sp. suspension.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

20.4 – 21.3 °C

pH:

7.50 – 7.66

Dissolved oxygen:

8.6 – 9.9 mg/L

Nominal and measured concentrations:

control; 100.0 mg/L WAF.

Details on test conditions:

- photoperiod: 16 h light : 8 h darkness
- no feeding
- no aeration.
- The volume of the test concentration and test medium for the control in every replicate was 100 mL.
- Five individuals of Daphnia magna were used in each replicate (20 mL of test solution per daphnid in accordance with the OECD Guideline which requires at least 2 mL). The test concentration and control was tested in four replicates.
- The pH and dissolved oxygen content were measured in the fresh solutions before division into replicates and in every replicate of used solutions

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC0

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.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- The immobilization effect of the test itemon Daphnia magna was estimated. The concentration of the test item and the test design in the definitive test were determined based on the preliminary test results.
- The validity criteria for the definitive test were met according to OECD Guideline No 202 (2004).
- No toxicity was observed up to the solubility limit of the test item in the test medium under the test conditions.

Results with reference substance (positive control):

The test on reference substance – potassium dichromate was performed at a temperature of 19.5 – 20.1 °C, oxygen concentration 8.1 – 9.4, Elendt M7 medium).
The test was performed from August 6 to August 8, 2012. The reference substance used for testing was provided by POCH (Polskie Odczynniki Chemiczne, Gliwice, Poland).
The reference substance was used in six concentrations: 0.18 - 3.20 mg/L. Every concentration and control was tested in four replicates. The results of the test are given in Appendix 2. The EC50 (24 h) value was 0.95 mg/L and EC50 (48 h) value was 0.36 mg/L.

Reported statistics and error estimates:

No statistics performed.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: public literature, limited details on experimental conditions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

yes

Details on test solutions:

- stock solutions were prepared with tetrahydrofuran (THF not in excess of 0.01% (v/v) in the final exposure solution

Test organisms (species):

Daphnia pulex

Details on test organisms:

Daphnia Pulex: collected from ShinikePond (Ehime, Japan), and single individual was isolated for clone culture.
Single-clone population was cultured at 19-21°C at pH 7-7.5.
Aged tap water was used as culture medium.
Established population was maintained for more than 3 months before the experiment.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Nominal and measured concentrations:

0.1., 0.5, 1.0, 5.0, 10mg/l

Details on test conditions:

Toxicity testwas conducted under the same condition as for the clone culture.
photoperiod: 16h light, 8h dark
20 neonates (age<24h) were placed in 30ml glass beaker containing 25ml of the test solution for each concentration and control.
Test organisms were not fed during the testing period. 3 replicates were tested.

Observation: afer 24h, 48h

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Basis for effect:

not specified

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Basis for effect:

not specified

Description of key information

With high probability acutely not toxic to aquatic invertebrates. No toxic effects occur at a nominal concentration of 100 mg/L WAF (water accommodated fraction). 

Additional information

The key study from the Institute of Industrial Organic Chemistry Branch Pszczyna (2012) is a static toxicity study. In this test young Daphnia magna individuals (< 24 h old) were exposed to the test item for 48 hours. A nominal concentration of 100 mg/L WAF (water accomodated fraction) was applied as a limit test. The EC50 causing 50% immobilization of the Daphnia magna population during 48 hours exposure is higher than 100.0 mg/L WAF. The EC0 (48 h) is higher than or equal to 100.0 mg/L WAF. No toxicity was observed up to the solubility limit of the test substance in the test medium under the test conditions.

Additionally published data on acute Daphnia toxicity are available. Vehicle was used. Limited details on the experimental conditions were given. However, the EC50 48h was above the highest tested concentration of 10mg/L (nominal).

A non-GLP guideline study according to OECD 202 (Ciba Geigy 1984) was disregarded because the exposure time was only 24 instead of 48h. Moreover, the preparation of the test substances was conducted with a solubilizer.

In conclusion, the substance is regarded as acutely not toxic to aquatic invertebrates. No toxic effects could be recorded in the range of water solubility.