Chloromethyltrimethylsilane

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

Study period:

2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD Guideline Study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

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

Test material information

Constituent 1

Reference substance name:

Chloromethyltrimethylsilane

EC Number:

219-058-5

EC Name:

Chloromethyltrimethylsilane

Cas Number:

2344-80-1

Molecular formula:

C4H11ClSi

IUPAC Name:

(chloromethyl)trimethylsilane

Test material form:

other: colourless liquid

Details on test material:

Purity 99.8%

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

For the analysis of the test item concentrations, one sample from the
freshly prepared test media of all test concentrations and the control
were taken.
For the determination of the stability of the test item under the test
conditions. and of the maintenance of the test item concentrations
during the test period, duplicate samples from the test media of all
test concentrations and the control were collected at the end of the
test (after 48 hours).
Since the test item is volatile, the samples were given to the
analytical department in closed Erlenmeyer flasks.

Test solutions

Vehicle:

no

Details on test solutions:

The concentrations of the test item Chloromethyltrimethylsilane
were analysed in all duplicate test media samples from both
sampling times (0 and 48 hours). From the control samples only one
of the duplicate samples was analysed from each of both sampling
times.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna (Straus), clone 5
From 5 to < 24 hours old.
Female.
ECT Oekotoxikologie GmbH, Bottgerstr. 2 - 14, 65439 Florsheim
am Main, Germany.
The Daphnia were bred in the laboratories of IDACON under
similar temperature and light conditions as used in the test. The
cultivation of the parental Daphnia was performed in reconstituted
water of a similar quality with regards to pH, the constituent salts
and total hardness as the culture medium used in the test (see 6.5).
The test organisms were not first brood progeny. Once a week the
Daphnia in the stock culture were fed with Tetra Min-extract and at
least all other working days with green algae (Desmodesmus
subspicatus) freshly grown in the laboratories ofIBACON.
For the evaluation of the quality of the Daphnia clone used and the
consistency of the experimental conditions, the reference item
potassium dichromate p.A. is tested at least twice a year to
demonstrate satisfactory test conditions.
Acclimatisation was not necessary since the breeding was performed
in the same kind oftest water.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

no data

Test conditions

Hardness:

2.5 mmol/L (= 250 mg/L) as CaCO3

Test temperature:

19 - 20 QC

pH:

pH 6.4 - 7.1

Dissolved oxygen:

At least 8.8 mg/L or higher

Salinity:

Main Compounds
CaCl·2 H20 293.80 mg/L
MgS04·7 H20 123.30 mg/L
KCI 5.80 mg/L
NaHC03 64.80 mg/L
Na2Si03·9 H20 10.00 mg/L
NaN03 0.27 mg/L
KH2P04 0.14 mg/L
K2HP04 0.18 mg/L

Nominal and measured concentrations:

29.3, 13.3, 6.05, 2.75 and 1.25 mg test itemIL and a control.

Details on test conditions:

Controlled environment room.
18-22°C with a maximum deviation of± 1°C within 48 hours.
>3 mg/L.
6-9; the pH-value did not vary by more than 1.5 units.
16 h light: 8 h dark.
0-1200 lux.
Test conditions were recorded with suitable instruments and
documented in the raw data.

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

ca. 8.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 6.9 - 9.5

Details on results:

In the control and in the test concentrations up to and including
6.05 mg test itemIL no immobilization of the test animals was
observed. At 13.3 mg test item/L 11 Daphnia were immobile and at
29.3 mg test item/L all Daphnia were immobile.
The toxicity of the test item to Daphnia magna had increased during
further 24 hours of exposure. In the control and in the test
concentrations up to and including 2.75 mg test item/L no
immobilisation or other signs of intoxication occurred. In the test
item concentration 6.05 mg test item/L 1 Daphnia was immobile at
that time, which was not assessed to be significant by the statistical
evaluation. At the two highest test concentration of 13.3 and 29.3
mg/L all Daphnia were immobile.

Results with reference substance (positive control):

no data

Reported statistics and error estimates:

Based on the results of TC and IC measurements the DOC content
of the test samples was determined using TC and IC calibration
curve and recalculated to the respective concentration of test
concentration.

Any other information on results incl. tables

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.

For the determination of the test concentrations a range-finding test

was performed.

The pre-experiments to the solubility of the test item and the rangefinding

test were not performed in compliance with the GLP Regulations

and are excluded from the Statement of Compliance.

However, the raw data of these tests will be archived under the

project number of the present study.

29.3, 13.3, 6.05, 2.75 and 1.25 mg test item/L and a control.

In the control, test water was used without addition of the test item.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The toxic effect of the test item Chloromethyltrimethylsilane to
Daphnia magna was assessed in a static dose-response test.
The 48hour EC50 value was 8.1 mg test item/L.

Executive summary:

The toxic effect of the test item Chloromethyltrimethylsilane to

Daphnia magna was assessed in a static dose-response test. The 48hour

EC50 value was 8.1 mg test item/L.

48-hour EC50: 8.1 mg test item/L

95 % confidence values: 6.9 - 9.5 mg test item/L

48-hour EC0: 2.75 mg test item/L

48-hour EC100: 13.3 mg test item/L

48-hour NOEC: 6.05 mg test item/L

48-hour LOEC: 13.3 mg test item/L