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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1997
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was performed under GLP according to EEC directive 92/69, C2 and OECD 202

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:
other: 92/69/EEC, C2 (Acute toxicity for Daphnia)
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): SILANE, TRIETHOXY [2-(7-OXABICYCLO[4.1.0]HEPT-3YL)ETHYL]
- Physical state: Clear, pale liquid
- Analytical purity: 100%
- Lot/batch No.: 16465-80
- Expiration date of the lot/batch: 1999-01-06
- Stability under test conditions: no stability in water
- Storage condition of test material: At room temperature in the dark, stable under storage conditions
- Other: Density: 1.00

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: 0, 10,18, 32, 56, 100, 180 mg/l
- Sampling method: An amount of 10.0 ml of each sample was pipetted into a suitable test tube. An amount of 792 µl acetonitrile was added to the 0, 32, 56, 100 and 180 mg/l samples. An amount of 53 µl acetonitrile was added to the 10 mg/l samples.
- Sample storage conditions before analysis: all samples not analysed on the same day of sampling were frozen until analysis

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
other aquatic crustacea: Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna
- Age at study initiation (mean and range, SD): < 24 hours
- Method of breeding: Start of each batch: With newborn animals, i.e. less than 3 days old, by placing about 250 of them into 10 litres of medium in an all-glass culture vessel. Maximum age of the cultures, 4 weeks. After 4 days of cultivation renewal half of the medium twice a week. Medium: M7, temperature 18-22°C ± 1°C. Feeding: Daily, a suspension of fresh water algea.
- Feeding during test: no feeding



Study design

Test type:
flow-through
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
no data
Test temperature:
20.5
pH:
7.8 - 8.2
Dissolved oxygen:
9. 5- 9.7 mg O2/l
Salinity:
not applicable
Nominal and measured concentrations:
See table 1 and 2
Details on test conditions:
TEST SYSTEM
- Test vessel: All-glass culture vessel
- Material, size, headspace, fill volume: 1.5 litres, glass, with 2 mesh containers of stainless steel
- Aeration: no
- Renewal rate of test solution (frequency/flow rate): continuous renewal of test media
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2



TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Tap water
- Total organic carbon: 1.9 mmol/l
- Metals: <0.04 - 78000 µg/l
- Chlorine: no chorine was present
- Ca/mg ratio: 78000/9200 µg/l
- Culture medium different from test medium: yes; culture medium: M7; test medium: tap water


OTHER TEST CONDITIONS
- Photoperiod: 16 hours daily


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobility and mortality were observed at 24 hours and at 48 hours.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Range finding study
- Test concentrations: 0.1, 1.0, 10, 100 mg/l
- Results used to determine the conditions for the definitive study: Under static conditions no significant (> 10%) effect on mobility of Daphnia magna was observed at any of the concentration tested. Analysis showed that the recovery of the substance components decreased by 35% during the first 24 hours. Hence, it was decided to perform the final test under flow-through conditions.
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
82 mg/L
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
58 mg/L
Duration:
48 h
Dose descriptor:
EC100
Effect conc.:
109 mg/L
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
32 mg/L
Details on results:
See table 3
Results with reference substance (positive control):
No positive control during the final test. It was conducted a separate reference test with potassium dichromate. This reference test was carried out to check the sensitivity of the test system as used by NOTOX. Test result: The D. magna originating from this batch can be considered as sensitive to toxic substances.
Reported statistics and error estimates:
EC50 (48h) = 58.3 mg/l
95% fiducial limits: 52.8 - 67.7 mg/l

Any other information on results incl. tables

Table 3: Acute immobilization of daphnia after 24 and 48 hours in the final EC50 -test

 Concentration mg/l (nominal)  Concentration mg/l (actual)  Vessel code  number exposed  number of immobile organisms at 24h (numbers between brackets relate to Daphnia trapped at the surface of the test solution) number of immobile organisms at 48h 
 10  11  A  10  0
 10  11  B  10  0
 18  20 (an estimated recovery of 110%)  A  10  0
 18  20 (an estimated recovery of 110%)  B  10  0 0
 32  33  A  10  0
 32  33  B  10  0
 56  60  A  10  0 (9)
 56  60  B  10  0 (6)
 100  109  A  10  9 (10)  10
 100  109  B  10  8 (10)  10
 180  293 (test substance drops were observed floating at the surface of the solution)  10  10  10
 180  293 (test substance drops were observed floating at the surface of the solution)  B  10 10   10

 Blank-control   

 A  10  0  0

 Blank-control   

 B  10  0  0

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Under the conditions of the present study the substance did not induce acute immobilization of Daphnia magna at a concentration of 32 mg/l (NOEC)
Executive summary:

The study procedure were based on the EEC directive 92/69, Part C.2 and the OECD 202.

After a static rang finding test with Daphnia magna exposed to concentrations ranging form 0.1 to 100 mg/l, a final test was performed under flow-through conditions as the substance proved to be unstable in the test medium.

The final test was performed in duplicate with 10 daphnia per vessel (concentration ranging from 10 - 180 mg/l and control).

The test substance was used as such for the stock and remained homogeneous under continuous stirring. The stocks were dosed via a computer controlled system consisting of 6 dispensers (Gilson). The dosed volume entered a mixing flask where it was mixed with tap water supplied with a flow rate of ca. 12 l/h. The whole system was checked daily.

Exposure was started 2 days after the start of the system, permit stabilization of the test concentrations.

The analytical program showed that the actual concentrations of both isomers of the substance could be maintained at levels between 100 and 120 % of the concentrations relevant for the determination of the toxicity parameters. The actual exposure concentrations approximated an overall recovery of 110% of nominal with the exception of the highest concentration which appeared to have exceeded water solubility.

SILANE, TRIETHOXY [2-(7-OXABICYCLO[4.1.0]HEPT-3YL)ETHYL] did not induce acute immobilization of Daphnia magna at a concentration of 32 mg/l (NOEC).

The 24h-EC50 of daphnia exposed to the substance was 82 mg/l with 95% fiducial limits of 77 and 91 mg/l.
The 48h-EC50 of Daphnia exposed to the substance was 58 mg/l with 95% fiducial limits of 53 and 68 mg/l.