N-(3-(trimethoxysilyl)propyl)ethylenediamine

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1995-01-17 to 1995-01-19

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Test substance concentration determined in the stock solution used to prepare the test media.

Test substance concentration was determined in all treatments at the start and end of the test.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: A 1000 mg/l stock solution was prepared by mixing for 18 hours followed by filtration. The other treatments were prepared by dilution of the stock solution. The measured DOC concentration in the stock solution was 427 mg/l which was equivalent to 986 mg/l of the test substance.

- Controls: Dilution water

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM

- Common name: Daphnia magna

- Strain: Clone 5

- Source: Stock culture

- Age at study initiation (mean and range, SD): <24 h

- Method of breeding: Parthenogenetic reproduction

- Feeding during test: None

ACCLIMATION

- Acclimation conditions (same as test or not): yes

- Type and amount of food: sufficient to be consumed each day leaving no residue

- Feeding frequency: daily

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

The sum of the Ca2+ and Mg2+ ions was 2.5 mmol

Test temperature:

20 +/-1ºC

pH:

8.0 - 8.3

Dissolved oxygen:

8.0 - 8.4 mg/l

Salinity:

not applicable

Nominal and measured concentrations:

Nominal: 0(Control), 20, 35, 59, 108 and 197 mg/l

Measured concentration in stock solution used to prepare test media: 986 mg/l

Measured concentration in treatments at the start of the test: 0, 26, 36, 59, 106 and 194 mg/l

Measured concentration in treatments at the end of the test: 0, 19, 33, 58, 105 and 156 mg/l

The test results are interpreted with reference to nominal concentrations.

Details on test conditions:

TEST SYSTEM

- Test vessel:

- Type: open

- Material, size, headspace, fill volume: glass cylinder containing 10 ml of test medium

- Aeration: none

- No. of organisms per vessel: 5

- No. of vessels per concentration (replicates): 4

- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: Elendt M4 medium

- Intervals of water quality measurement: end of test

OTHER TEST CONDITIONS

- Photoperiod: Dark

EFFECT PARAMETERS MEASURED: Immobilization after 24 and 48 h exposure

TEST CONCENTRATIONS

- Spacing factor for test concentrations: 1.7

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

81 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

but exposure is to hydrolysis products

Basis for effect:

mobility

Remarks on result:

other: 59-108 mg/L

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

35 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

but exposure is to hydrolysis products

Basis for effect:

mobility

Details on results:

- Mortality of control: 10%

- Other adverse effects control: none reported

Results with reference substance (positive control):

48-h EC50: >1.0, <2.0 mg/l

Reported statistics and error estimates:

The EC50 and its confidence interval were determined by Probit analysis. The NOEC value was obtained directly from the raw data.

Table 1. Test results

Nominal test concentration (mg/l)	Mean percentage immobilisation after 24 hours	Mean percentage immobilisation after 48 hours
0 (Control)	0	10
20	0	0
35	0	0
59	10	15
108	50	80
197	90	90

Validity criteria fulfilled:

yes

Conclusions:

A 48 hour EC50 value of 81 mg/l and a NOEC of 35 mg/l have been determined for the effects of the test substance on mobility of Daphnia magna. The results are expressed relative to nominal concentrations of the test substance. However the substance is subject to rapid hydrolysis and under the test conditions it is therefore likely that exposure will have been to its hydrolysis products (methanol and N-(3-(trihydroxysilyl)propyl)ethylenediamine).

Description of key information

48-hour EC₅₀ 81 mg/l (nominal) (EU C.2), Daphnia magna. The EC₅₀ is equivalent to 66 mg/l when expressed in terms of the silanol hydrolysis product, N-(3-(trihydroxysilyl)propyl)ethylenediamine.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

66 mg/L

Additional information

A 48-hour EC₅₀ value of 81 mg/l (nominal) has been determined for the effects of the registration substance, N-(3 -(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3, EC 217-164-6), on mobility of Daphnia magna (Hüls, 1995). The results are expressed relative to nominal concentrations of the test substance. The test was conducted according to EU Test Method C.2 and in compliance with GLP. In view of the test media preparation method and exposure regime, it is likely that the test organisms were exposed predominantly to the hydrolysis products of the tested substance (methanol and N-(3-(trihydroxysilyl)propyl)ethylenediamine). The nominal test concentrations are supported by DOC analysis of the stock solutions and in the treatment concentrations at the start and end of the test.

The results may be expressed in terms of concentration of the silanol hydrolysis product, N-(3-(trihydroxysilyl)propyl)ethylenediamine, by applying a molecular weight correction: (MW of silanol = 180.28 / MW of parent = 222.36) * 81 = 66 mg/l.

This result has been selected as the lowest EC₅₀ value for effects on mobility from two reliable studies. The other EC₅₀ value was 90 mg/l. Another study to which it is not possible to assign a reliability score determined an EC₅₀ value of 37 ppm.