[2R[2R*(4R*,8R*)]]-3,4-dihydro-2,8-dimethyl-2-(4,8,12-trimethyltridecyl)-2H-benzopyran-6-ol

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10/05/1995 - 14/06/1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

other: published parts of study report

Title:

Unnamed

Year:

1995

Report date:

1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-benzopyran-6-ol

EC Number:

233-466-0

EC Name:

3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-benzopyran-6-ol

Cas Number:

10191-41-0

Molecular formula:

C29H50O2

IUPAC Name:

2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-3,4-dihydro-2H-1-benzopyran-6-ol

Test material form:

liquid: viscous

Specific details on test material used for the study:

No test surrogate or analogue material was used.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: nominal concentrations of 5.8, 10, 18, 32, 58 and 100 mg/l
- Sampling method: Water samples of each concentration were taken at 0 and 48 hour exposure and analyzed for the content of d,l-a-tocopherol. The 0 hour samples of each test concentration (2 x 150 ml volume each) were taken from one additional beaker (600 ml volume), which equilibrated in parallel to the original test beakers of each concentration during a time of 24 hours before test initiation. Additionally one sample was taken from the freshly prepared stock solution (50 ml). At test termination (48 hours), samples of about 80 ml were taken from three of the four replicate test vessels of each treatment group, of which at least one sample was analyzed.

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 200 mg test substance were added to 8 ml Tween 80 (0.1% w/v) and about 200 ml reconstituted water (M4-medium according to elendt)
and mixed for 1 minute with a Polytron-mixer. This dilution was filled up to 2000 ml with M4-medium (according to Elendt). Calculated amounts of
this stock solution were transferred to 1000 ml test medium and homogeneously distributed to produce the desired test concentrations.
- Controls: bare M4 medium
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Tween 80 (0.1%)
- Concentration of vehicle in test medium (stock solution and final test solution): Amounts of 3.77, 3.6, 3.28, 2.72, 1.68 and 0 ml per litre were added to the test concentrations of 5.8, 10, 18, 32, 58 and 100 mg d,l-a-tocopherol per litre, respectively.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): d,l-a-Tocopherol built a separate layer on the water surface after dilution with
the test medium

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS
- Strain: Clon 5
- Source: In-house culture of CIBA-GEIGY Limited
- Age at study initiation (mean and range, SD): <24 hours
- Method of breeding: In-house cultures of Daphnids were maintained in polypropylene vessels containing approximately 2.5 l of M4 medium. About one third of this culture medium was renewed three times a week. The daphnids were fed daily with a suspension of green algae (1.0 ml/L of a
Scenedesmus subspicatus suspension with a density of approx. 10^8 cells/ml). Cultering was performed under constant conditions. Three times a
week the young daphnids were separated to maintain a homogenous stock of animals.


ACCLIMATION
- Acclimation period: +/- 24 hours
- Acclimation conditions (same as test or not): 16/8h light/dark conditions, while test is carried out in the dark entirely.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

No post exposure observation period.

Test conditions

Test temperature:

20 +/- 2 °C

pH:

7.4 - 8.1, maximum increase of 0.6 during test

Dissolved oxygen:

0h: 97 - 100%
48h: 94 - 98%

Nominal and measured concentrations:

Nominal: 5.8, 10, 18, 32, 58 and 100 mg/l
Measured (0h): 4.9(4.7/5.0), 4.5 (4.5/4.5), 7.9 (7.8/8.1), 13.1 (13.1/13.0), 21.2 (20.0/22.3) and 30.3 (27.4/33.2) mg/l
Measured (48h): 2.0 (1.9/2.1), 2. (2.2/2.1), 4.0 (3.8/4.1), 5.8 (5.7/5.9), 9.9 (9.9/9.8) and 16.8 (16.1/17.4) mg/l
Effect concentrations were determined on the base of nominal concentrations.

Details on test conditions:

TEST SYSTEM
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass (150 ml, with 100 ml test solution)
- Aeration: paasive via diffusion
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water
- Culture medium different from test medium: No
- Intervals of water quality measurement: 48h

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: Test was carried out in the dark

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Range finding study
- Test concentrations: 0.01, 0.1, 1, 10 and 100 mg/l
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 23.53 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: nominal > 100 mg/L

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

9.43 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: nominal 32 mg/L

Details on results:

- Behavioural abnormalities: no abnormalities reported
- Other biological observations: No unexpected phenomena reported
- Mortality of control: less than 10%
- Abnormal responses: None reported
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: d,1-a-Tocopherol built a separate layer
on the water surface after dilution with the test medium. The substance also stuck all over the daphnids.
- Effect concentrations exceeding solubility of substance in test medium: No

Results with reference substance (positive control):

No reference substance used.

Reported statistics and error estimates:

No data on statistics, errors or confidence intervals available.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

no mortality in control

Conclusions:

The 48h EC50 of d,l-alpha-Tocopherol to Daphnia magna was found to be > 23.53 mg/l, 48h; NOEC was found to be 9.43 mg/l

Executive summary:

The toxicity of d,l-alpha-Tocopherol towards Daphnia magna was determined according to OECD Guideline 202 under GLP. Exposure concentrations decreased during exposure period, therefore concentrations are expressed on average measured concentrations. The 48h EC50 of d,l-a-Tocopherol to Daphnia magna was found to be > 23.53 mg/l, 48h NOEC was found to be 32 mg/l.