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

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999-5-24 to 1999-9-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study according to OECD 203

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 203 (Fish, Acute Toxicity Test)

Version / remarks:

adopted on 17th July 1992

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, a nominal concentration of 100 mg/L was selected for each limit test. This concentration was chosen based on the recommendations of the Guidance Document for Testing Difficult Substances and OECD Guideline (1984). To prepare the test solution, 0.9001, 0.9002 and 0.9005 grams of test item was added directly to each test chamber replicate containing 9 Liters of dilution water. The dilution water/chemical mixtures were stirred for 24-hours and filtered through a 0.2 µm SuporCap™ filter from Gelman Sciences to make three composite replicates. One liter of the composited test solution was collected for WAF analysis. A dilution water control was maintained concurrently with the test solutions.

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow Trout
- Source: Thomas Fish Camp, Anderson, California.
- Length at study initiation (length definition, mean, range and SD): 45 +/- 2.4 mm
- Weight at study initiation (mean and range, SD): 1.35 +/- 0.23 g
- Feeding during test: no

ACCLIMATION
- Type of food: salmon starter (obtained from Zeigler Brothers, Inc., Gardners, PA)
- Feeding frequency: until 24 hours prior to the test initiation
- Health during acclimation (any mortality observed): Rainbow trout appeared to be in good health at test initiation and mortality was 0% during the 48 hours prior to test initiation.

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Test conditions

Hardness:

54 to 68 mg/L as CaCO3

Test temperature:

13.8 to 15.4°C

pH:

7.5 to 6.3

Dissolved oxygen:

9.2 and 9.5 mg/L (92 to 94% of saturation) at test initiation

Nominal and measured concentrations:

100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: 3.5-gallon glass jars (22-cm diameter x 30-cm height) containing 9 L of dilution water and providing a water depth of approximately 25 cm.
- Aeration: no aeration
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
- Biomass loading rate: 1.5 g of fish tissue per liter of test solution.

TEST MEDIUM / WATER PARAMETERS
- in accordance to the guideline

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: photoperiod of 16 hours light and 8 hours darkness
- Light intensity: The light intensity ranged between 8.9 and 10.8 micromols per square meter per second.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: loading rate

Basis for effect:

mortality (fish)

Remarks on result:

other: No acute toxicity within the range of solubility

Effect concentrations 2

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: loading rate

Basis for effect:

mortality (fish)

Remarks on result:

other: No acute toxicity within the range of solubility

Details on results:

- Mortality of control: 7%

Reported statistics and error estimates:

Based on the results and design (only one test treatment) of the test, the 96-hour LC50 value, its 95 percent confidence limits, and the slope of the concentration/mortality response curve could not be calculated.

Applicant's summary and conclusion

Conclusions:

With high probability acutely not harmful to fish.