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Administrative data

Endpoint:
short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1997-01-13 - 1997-02-14
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report date:
1997

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
EU Method C.1 (Acute Toxicity for Fish)
Qualifier:
according to guideline
Guideline:
OECD Guideline 203 (Fish, Acute Toxicity Test)
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
4-bromobenzonitrile
EC Number:
210-764-9
EC Name:
4-bromobenzonitrile
Cas Number:
623-00-7
Molecular formula:
C7H4BrN
IUPAC Name:
4-bromobenzonitrile
impurity 1
Chemical structure
Reference substance name:
2-bromobenzonitrile
EC Number:
218-045-1
EC Name:
2-bromobenzonitrile
Cas Number:
2042-37-7
Molecular formula:
C7H4BrN
IUPAC Name:
2-bromobenzonitrile
impurity 2
Chemical structure
Reference substance name:
3-bromobenzonitrile
EC Number:
230-127-9
EC Name:
3-bromobenzonitrile
Cas Number:
6952-59-6
Molecular formula:
C7H4BrN
IUPAC Name:
3-bromobenzonitrile
impurity 3
Chemical structure
Reference substance name:
Benzonitrile
EC Number:
202-855-7
EC Name:
Benzonitrile
Cas Number:
100-47-0
Molecular formula:
C7H5N
IUPAC Name:
benzonitrile
impurity 4
Chemical structure
Reference substance name:
Water
EC Number:
231-791-2
EC Name:
Water
Cas Number:
7732-18-5
Molecular formula:
H2O
IUPAC Name:
Water
Test material form:
solid

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: 0, 16, 25, 40 mg/mL at start of exposure; 0,16, 25 mg/mL at the end of exposure
- Sampling method: 10 mL from approximate centre of test vessels + 10 mL reserve samples
- Sample storage conditions before analysis: deep-freeze

Test solutions

Vehicle:
no
Details on test solutions:
The standard test procedures required generation of test solutions which contain completely dissolved test substance concentrations or stable and homogeneous mixtures or dispersions. The testing of concentrations that disturbed the test system were prevented (e.g. film of the test substance on the water surface).

All the test concentrations were prepared seperately, owing to the poor solubility of the test substance in the test medium. After pulverisation of the test substance, ultrasonic treatment and magnetic stirring were used alternately to accelerate suspending. In addition, the temperature was increased uo to 40 °C. Before introduction of the fish test solutions cooled to 22 °C. Final test solutions were all clear with test subtance particles present in the medium. The amount of test substance particles increased with increasing test concentration.

Test organisms

Test organisms (species):
Cyprinus carpio
Details on test organisms:
- mean length
Range-finding: 2.97 +/- 0.31 cm
Final test: 2.4 +/- 1.4 cm

Mean weight:
Range-finding: 0.84 +/- 0.31 g
Final test: 0.44 +/- 0.05 g

Study design

Test type:
static
Water media type:
freshwater
Remarks:
ISO Medium
Total exposure duration:
96 h

Test conditions

Test temperature:
20.8 - 22.0 °C
pH:
7.5 - 8.3
Dissolved oxygen:
7.5 - 9.1
Reference substance (positive control):
yes
Remarks:
Pentachlorophenol (PCP)

Results and discussion

Effect concentrations
Key result
Duration:
96 h
Dose descriptor:
EC50
Effect conc.:
ca. 32 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality (fish)

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
1. No mortality was observed in the control group. 2. Measured concentrations corrsepond with an estimated average exposure concentration of 60 % during the test. 3. Further, all test conditions remainded within the ranges prescribed by the protocol.
Conclusions:
Under the conditions of the present test 4-Bromobenzonitrile induced such severe effects at 40 mg/L and higher, that these effects had to be considered as lethal.
Based on nominal concentrations the 96 h LC50 was 32 mg/L. This LC50 value corresponded with actual average exposure concentration of 19 mg/L.
Executive summary:

96 h Acute Toxicity Study in Carp with 4 -Bromobenzonitrile.

The study procedures were based on the ECC directive 92/69, Part C.1. "Acute toxicity for fish": and the OECD guideline No. 203: "Fish Acute Toxicity Test", adopted 17 July, 1992.

The test was performed with carp exposed to concentrations ranging from 16 to 160 mg/L in a static system. 7 carp were exposed per concentration and a control. Samples for TOC-analysis were taken at the start and at the end of the test.

Test substance particles were present in all test solutions during the test. At the start of exposure the actual TOC recoveries ranged between 49 and 53 %. After 96 h of exposure, TOC recoveries had increased to approximatley 72 %. The increase of recoveries was probably caused by further dissolving of the test substance during the test. Hence, the actual average exposure concentrations were maintained an an astimated 60 % of nominal.

Under the conditions of the Present test 4 -Bromobenzonitrile induced no lethal effects in carp at or below 25 mg/L. The 96 h LC50 was 32 mg/L based on nominal concentrations with 0 % mortality at 25 mg/L and 100 % mortality at 40 mg/L. This LC50 value corresponded with an actual average concentration of 19 mg/L.

The "Bewertungszahl" is 4.5 based on the nominal LC50 and 4.7 based on the actual LC50.