2,6-bis(1,1-dimethylethyl)-4-(phenylenemethylene)cyclohexa-2,5-dien-1-one

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:

1999-05-07 to 1999-09-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guidelne study according to OECD 202

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

adopted on 4th April 1984

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

429-460-4

EC Name:

-

Cas Number:

7078-98-0

Molecular formula:

C21 H26 O

IUPAC Name:

2,6-bis(1,1-dimethylethyl)-4-(phenylenemethylene)cyclohexa-2,5-dien-1-one

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method:
Since the test item has very low solubility, especially the main component, the recommendations of the Guidance Document for testing difficult substances (Department of the Environment, 1996) and OECD guideline (1992) were followed. A limit test was conducted at 100 milligrams per liter (mg wm/L). The test solution was prepared by weighing out the appropriate amount of test item (0.4 grams), directly adding it to 4 liters of dilution water and stirring for 48-hours before being filtered through a sterile 0.2 µm. SuporCap™ filter originating from Gelman Sciences. A dilution water control was maintained concurrently with the tes solution.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain: Daphnia magna
- Source: Aquatic Research Organisms, Hampton, NH
- Feeding during test: no

ACCLIMATION
- Acclimation period: seven days preceding test initiation
- Acclimation conditions (same as test or not):
- Type and amount of food: The cultures were fed green algae, Selenastrum capricornutum, and a solution prepared from yeast, cereal leaves (Cerophyll®), and trout chow (YCT) daily.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

66 mg/L as CaCO3

Test temperature:

19.2 to 20.0°C

pH:

7.2 and 7.4

Dissolved oxygen:

8.8 to 9.1 mg/L (97 to 100 percent of saturation)

Nominal and measured concentrations:

100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: 300-mL glass crystallizing dishes containing approximately 200 mL of dilution water
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 25 water fleas/L

TEST MEDIUM / WATER PARAMETERS
-in accordance to the guideline

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: hours light and 8 hours darkness

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: loading rate

Basis for effect:

mobility

Remarks on result:

other: No acute toxicity within the range of solubility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: loading rate

Basis for effect:

mortality

Remarks on result:

other: No acute toxicity within the range of solubility

Details on results:

- Mortality of control: no

Reported statistics and error estimates:

Based on results of the test, the 24- and 48-hour EC50 values and their 95 percent confidence limits can not be calculated. However, it can be concluded that the 48-hour EC50 is >100 mg/L from the absence of mortality in the test.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

With high probability acutely not harmful to aquatic invertebrates.