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Ecotoxicological information

Short-term toxicity to fish

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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

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
429-460-4
EC Name:
-
Cas Number:
7078-98-0
Molecular formula:
C21 H26 O
IUPAC Name:
2,6-di-tert-butyl-4-(phenylmethylidene)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 concentrationsopen allclose all
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
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.