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

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013-11-18 to 2014-02-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study according to OECD guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

yes

Remarks:

According to OECD Guideline No. 211 the recommended range of temperature is 18 - 22 C with variation not exceeding 2 C within these limits as daily range. In the definitive test the temperature was in a range of 19.2 – 21.7 C with a variation of 2.5 C.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)

- Method: the Water Accommodated Fraction of the test item in test medium was used for exposure (10 mg/L)
- Controls: test medium
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): water
- each of them was sonicated for 15 min at 40°C temperature (ultrasonic bath, Sonic- 10, Polsonic and then mixed continuously by mechanic shaker at 60 rpm at room temperature for 24 h (mechanic shaker, JWElectronic)
- afterwards, the separation by a filtration through a conditioned nitrocellulose membrane filter was performed (HAWG filter, pore size: 0.45 μm, Millipore)
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no, the filtrates, i.e. the Water Accommodated Fraction (WAF) were clear, colourless and homogeneous.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM

- Name: Daphnia magna Straus
- Source: standard culture maintained at the Institute of Industrial Organic Chemistry Branch Pszczyna
- Age of parental stock: : Daphnia magna Straus (< 24 h old at the exposure initiation); not first brood progeny; range of parent Daphnia magna age: 21 – 25 days

- Feeding during test: yes
- Food type: with algal suspension mixture: Pseudokirchneriella subcapitata : Desmodesmus subspicatus (2:1, volume per volume)
- Amount: 0.2 mg organic carbon per Daphnia per day

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

21 d

Hardness:

198.83 – 211.83 mg CaCO3/L

Test temperature:

The temperature was in a range of 19.2 – 21.7 C with a variation of 2.5 C .
However, the daily range was with a variation of up to 2.0 C with only one exception; on day 9 the daily range was 2.1 C.

pH:

7.46 – 7.75 (fresh solutions)
7.66 – 8.37 (old solutions)

Dissolved oxygen:

8.1 – 8.8 mg/L (fresh)
8.0 – 9.4 mg/L (old)

Nominal and measured concentrations:

- nominal: WAF of a loading of 10 mg/L
- no measured concentration (below detection limit)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers with a capacity of 150 mL containing at 100 mL of solution
- Type: closed
- Renewal rate of test solution: 3 renewals of test item concentration and the control per week were performed
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10


TEST MEDIUM / WATER PARAMETERS
- in accordance with the guideline


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: light : dark cycle of 16 h : 8 h was used with fluorescent light source application
- Light intensity:

EFFECT PARAMETERS MESURED:
The offspring produced in each test vessel was counted and removed daily. The observations on immobilization of parent Daphnia magna were reported daily.

VEHICLE CONTROL PERFORMED: no vehicle used

RANGE-FINDING STUDY
In order to find conditions of exposure for Daphnia magna in the definitive reproduction test the preliminary non-GLP acute immobilization test and preliminary non-GLP reproduction test were performed.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: NOEC >= WAF of a loading of 10 mg/L

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: LOEC > WAF of a loading of 10 mg/L

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

immobilisation

Remarks on result:

other: EC10/21 d > WAF of a loading of 10 mg/L

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

immobilisation

Remarks on result:

other: EC50/21 d >WAF of a loading of 10 mg/L

Details on results:

- Mortality of parent animals: no mortality occured
- No. of offspring produced per day per female: 8.1-9.8 (control) ; 8.0-10.9 (test item)
- Body length parent animals: 3.58 (control, mean) ; 3.59 (test item, mean)
- Type and number of morphological abnormalities: non
- Type and number of behavioural abnormalities: non

Results with reference substance (positive control):

The sensitivity of the culture was monitored on regular basis with the reference substance potassium dichromate.
No results were presented in the study report.

Description of key information

The results of the limit semi-static 21-d Daphnia magna reproduction test demonstrated no effects of test item concentration i.e. WAF of a loading of 10 mg/L on reproductive output (the mean cumulative number of offspring per survivor), immobilization, final body size of parent Daphnia, intrinsic rate of population growth and age of first reproduction.
The NOEL was thus determined to be > 10 mg/L (loading rate).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

10 mg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

10 mg/L

Additional information

In a semi-static reproduction test according to OECD Guideline 211, young Daphnia magna (< 24 h old) were exposed to the test item for 21 days. (PSZCZYNA, 2014 , W/86/13).

The test item was used in a single test item concentration as a limit test. Since the test item was of low solubility, the Water Accommodated Fraction (WAF) of the test item in test medium was used for exposure.

The aim of a limit test was to demonstrate that the LOEC and NOEC values based on number of living offspring, immobilization and final body size (body length) of parent Daphnia magna are higher than the solubility limit of the test item in the test medium, or the WAF of a loading of 10 mg/L, respectively.

The test was performed in glass beakers with a capacity of 150 mL. Each of them contained 100 mL. The content of each beaker was completely renewed three times a week. At each renewal the parent Daphnia magna were transferred from old to fresh solutions. The offspring produced in each test vessel was counted and removed daily. The observations on immobilization of parent Daphnia magna were reported daily. The body size of each parent Daphnia magna was measured at exposure termination.

 

No effects were observed on reproductive output, immobilization, final body size, intrinsic rate of population growth and age of first reproduction. The endpoint values were based on nominal concentration of the test item expressed as the WAF of a loading of test item.

 

LOEC >WAF of a loading of 10 mg/L

NOEC > WAF of a loading of 10 mg/L

EC10/21 d >WAF of a loading of 10 mg/L

EC50/21 d >WAF of a loading of 10 mg/L