N-[(triethoxysilyl)methyl]cyclohexylamine

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:

April 13 - Aug 02, 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

October 2000

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

454-780-6

EC Name:

-

Cas Number:

27445-54-1

Molecular formula:

Hill formula: C12H27NO2Si CAS formula: C12H27NO2Si

IUPAC Name:

Cyclohexyl-((diethoxy-methyl-silanyl)-methyl)-amine

Test material form:

liquid

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

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in water very quickly, in the present test the hydrolysis products of the test item were tested, according to the draft guidance document on aquatic toxicity testing of difficult substances. Therefore, 315 mg test item were mixed into 1500 mL test water by intense stirring for 24 hours. Then, adequate volumes of the intensively stirred solution of the test medium will be mixed into test water to obtain the desired test concentrations.
The test media were prepared just before introduction of Daphnia (= start ofthe test).

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Age at test start:
- 7 hours and 30 minutes to 23 hours and 15 minutes old
- females
Origin:
- supplied 1997 by the Umweltbundesamt, Institut fUr Wasser-, Boden- und Lufthygiene, Berlin, Germany
Breeding conditions:
- The Daphnia were bred in the laboratories of IBACON under similar temperature and light conditions 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 (see below). The test organisms were not fIrst brood progeny. The Daphnia of the stock culture were fed at least each working day with green algae (Desmodesmus subspicatus) freshly grown in the laboratories ofIBACON.
Toxic Standard:
- 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.
Acclimatisation:
- for 7 hours and 30 minutes under test conditions

Study design

Test type:

static

Water media type:

other: Reconstituted Water (Elendt "M4") with a Hardness of 2.5 mmol/L (= 250.0 mgIL) as CaC03

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

2.5 mmol/L (= 250.0 mg/L) as CaC03

Test temperature:

20°C

pH:

7.0 -7.6

Dissolved oxygen:

At the end of the test the dissolved oxygen concentration in the test media was >= 2 mg O2/L in the control and test vessels.

Salinity:

not applicable

Nominal and measured concentrations:

Nominal 11, 23, 48, 100 and 210 mg test item/L and a control
Mean Recovery in the Test Samples:
after 0 h: 86 % (n = 10, SD 2 %)
after 48 h: 82 % (n = 10, SD 4 %)
The analytically determined mean test item concentrations in the analysed test media varied in the range from 81 % to 87 % of the nominal values. In the test media the test item was sufficiently stable during the test period of 48 hours. Therefore, all reported biological results are related to the
nominal concentrations of the test item.

Details on test conditions:

Test Units:
- glass beakers of 100 mL volume with 80 mL test medium
- Each test unit was uniquely identifIed with study number,treatment and replicate number.
Test conditions:
- controlled environment room
- Light Regime: 16 h light: 8 h dark
- Light Intensity: 150 - 420 lux
Introduction of individuals:
- 20 Daphnia per control and test concentration, divided into 4 groups of 5 animals, each group in 80 mL test medium

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 210 mg/L

Nominal / measured:

nominal

Conc. based on:

other: test mat. / but exposure is to hydrolysis products

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

48 mg/L

Nominal / measured:

nominal

Conc. based on:

other: test mat. / but exposure is to hydrolysis products

Basis for effect:

mobility

Details on results:

After 48 hours in the control and in the test concentrations up to 48 mg test item/L no mortality or immobilization of the test animals was observed and in the test concentrations 100 and 210 mg/L mortality or immobilization was statistically significantly affected compared to the control. The immobilization rate was 10.0 and 35 % in the 100 and 210 mg test item/L treatment groups, respectively.
Table 2). The 48-hour EC 50 and the 48-hour EC 100 of
Geniosil210 mg test item/L. These values could not be quantified,
since concentrations in excess of 210 mgIL have not been
tested.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

A 48-hour EC50 value of >210 mg/L and a NOEC of 48 mg/L have been determined for the effects of the test substance on mobility of Daphnia magna based on nominal exposure concentrations of the substance. The test substance hydrolyses in water and it is therefore likely that the test organisms were primarily exposed to the hydrolysis products of the substance.