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Ecotoxicological information

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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: OECD Guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report date:
2003

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Chemical Name:3-[(2,2-Dimethyl-1 ,2-azasilolidin-1-yl)(dimethyl)silyl]-l-propanamin
Aggregate State: liquid
Colour:colourless-yellowish
Storage: refrigerator
Stability: instable in water (::=; 1.0 min.)
Safety Precautions: Routine hygienic procedures were sufficient to assure personnel health and safety

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Duplicate samples from the freshly prepared test media of the only test concentration and the control were taken at the start and at the end of the test.

Test solutions

Vehicle:
no
Details on test solutions:
In deionised water (conductivity < 5 µScm-1) analytical grade salts were added to following nominal concen-trations:
CaC12 x 2H20 2.0 mmol/L (= 294.0 mg/L)
MgS04 x 7H20 0.5 mmol/L (= 123.0 mg/L)
NaHC03 0.75 mmol/L (= 65.0 mg/L)
KCl 0.075 mmol/L (= 5.8 mg/L)
Water Hardness 2.5mmol/L (= 250.0 mg/L) as CaC03
Alkalinity 0.8 mmol/L
Ratio of Ca : Mg = 4: 1 (based on molarity)
Na : K = 10 : 1 (based on molarity)

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Daphnia magna (Straus), clone 5, 6 - 21 hours old, female, supplied 1997 by the Umweltbundesamt, Insti-tut für Wasser-, Boden- und Lufthygiene, Berlin, Germany.
The Daphnia were bred in the laboratories of the testing facility under similar temperature and light con-ditions as in the test, and in reconstituted water of a similar quality regarding to pH, components of the main ions and total hardness as the test water used in the test. The test organisms were not first brood progeny. The Daphnia of the stock culture were fed at least each working day with green algae (Des-modesmus subspicatus) freshly grown in the laboratories . For the evaluation of the quality of the Daphnia clone and the experimental conditions the substance potassium dichromate p.A. is tested at least twice a year to demonstrate satisfactory test conditions.
The daphnids were acclimatized for 6.0 hours under test conditions in glass beakers of 100 mL volume with 75 mL test medium.
Light regime: 16 h light: 8 h dark; 840 lux; 20 Daphnia per control and test concentration, divided into 4 groups of 5 animals, each group in 75 mL test medium.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h
Post exposure observation period:
not reported

Test conditions

Hardness:
2.5mmol/L (= 250.0 mg/L) as CaC03
Test temperature:
21 °C
pH:
7.7 - 7.9
Dissolved oxygen:
at least 8.6 mg/L or higher
Salinity:
not reported
Nominal and measured concentrations:
measured, mean recovery in the fortified samples was 100 % (n = 4, SD 1 %) and mean recovery in the test samples: after 0 h: 98 % (n = 2, SD 1 %)
after 48 h: 97 % (n = 2, SD 0 %)
Details on test conditions:
Pre-experiments were performed to determine the solubility of the test item in test water and to select suitable methods for the preparation of a stock solution and the dosage of the test item into the test media.
The test concentration was based on the results of a rangefinding test. The pre-experiments to the solubility of the test item and the range-finding test were not performed in compliance with the GLP-Regulations. Hydroly-sis hydrolysis products of 150 mg test item/L and a control were used. In the control, test water was used with-out addition of the test item. Since the test item hydrolyses in water very quickly, in the present test the hy-drolysis products of the test item were tested, according to the draft guidance document on aquatic toxicity testing of difficult substances. Therefore, 75 mg test item were mixed into 500 mL test water by intense stir-ring for 24 hours. Thus, the main part of the test item were hydrolysis products.
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
> 150 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 150 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Duration:
48 h
Dose descriptor:
EC100
Effect conc.:
> 150 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
150 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Details on results:
In the control and in the test concentration of nominal 150 mg test item/L no immobilized or dead test animals were observed during the test period of 48 hours. After mixing the test item into test water, after a few minutes
the test medium became turbid. This turbidity was observed during the whole test period of 48 hours. After 24 and 48 hours test duration a very small part of the test item was lying at the bottom of the glass beakers.
Results with reference substance (positive control):
The reference substance worked as expected

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 48-hour EC 50 and the 48-hour EC 100 were clearly higher than 150 mg test item/L.
Executive summary:

The purpose of this study was to evaluate the influence of the test item on the mobility respectively survival ofDaphnia magna. in a immobilisation assay according to OECD guideline 202..Since the test item hydrolyses in water very quickly, in the present test the hydrolysis products of the test item were tested, according to the draft guidance document on aquatic toxicity testing of difficult substances. The test item was mixed into test water and stirred for 24 hours. Thus, the main part of the test item at the start of the test were hydrolysis products. Therefore, all results are related to the hydrolysis products of the test item. A limit test was performed to demonstrate that the test item has no toxic effect onDaphniaup to the test concentration of nominal 150 mg test item/L.

In the control and in the test concentration of nominal 150 mg test item/L no immobilized or dead test animals were observed during the test period of 48 hours. The 48-hour EC0 of the test item toDaphnia magnawas determined to be at least 150 mg test item/L. The EC0 might even be higher than this concentration, but concentrations in excess of 150 mg test item/L have not been tested. The 48-hour EC 50 and the 48-hour EC 100 were clearly higher than 150 mg test item/L. These values could not be quantified due to the absence of toxicity of the test item, up to the highest test concentration.