Carbamic acid, N-[(dimethoxymethylsilyl)methyl]-, methyl ester

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 Aug - 18 Oct 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Remarks:

Hessisches Ministerium für Umwelt, Landwirtschaft und Forsten

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control, 100 mg/L (after stirring for 3 d)
- Sampling method: Duplicate samples were taken at test start and test end.
- Sample storage conditions before analysis: samples were analysed directly

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Since the test item hydrolyses in water quickly, in the present test the hydrolysis products of nominal 100 mg/L were tested. For preparation of test solutions 602 mg test substance was mixed into 6 L test medium by intense stirring for 72 h. In a second experiment with identical conditions a stirring period of 24 h was chosen.
- Eluate: no
- Differential loading: no
- Controls: yes, test water control

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Source: Forellenzuchtbetrieb Tautenhahn, Trostadt, Germnay
- Age at study initiation: juveniles
- Length at study initiation (length definition, mean, range and SD): 4.3 ± 0.2 cm
- Weight at study initiation (mean and range, SD): 0.7 ± 0.2 g
- Feeding during test: none

ACCLIMATION
- Acclimation period: 14 d
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: commercial fish diet until 1 d prior to exposure
- Health during acclimation (any mortality observed): no mortality observed, all fish in healthy conditions

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

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

Test temperature:

16 - 17 °C

pH:

7.6 - 8.1

Dissolved oxygen:

8.6 - 9.5 mg O2/L

Nominal and measured concentrations:

nominal: control, 100 mg/L
measured: In the mean 89% of nominal were found. Thus, during the test duration the fish were exposed to the hydrolysis products of a mean of 89 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: Aquaria
- Material, size, headspace, fill volume: glass, 8 L, headspace: 2.5 L, fill volume: 5 L
- Aeration: slightly aerated
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: deionised water
- Alkalinity: 0.8 mmol/L
- Ca/mg ratio: 4:1 (based on molarity)
- Conductivity: < 5 µS/cm-1
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light / 8 h dark
- Light intensity: 560 - 800 lux

EFFECT PARAMETERS MEASURED
- Mortality and Symptoms of Intoxication: after 2, 24, 48, 72 and 96 h

TEST CONCENTRATIONS
- Spacing factor for test concentrations: not applicable, limit test
- Range finding study: A range-finding study was performed but not reported in detail.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

but the exposure was to hydrolysis products

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

but the exposure was to hydrolysis products

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: not observed
- Mortality of control: 0%
- Other: A stirring period of 24 h did not affect the results of the study (based on data from an additional experiment)

Validity criteria fulfilled:

yes

Conclusions:

A 96 h LC50 of > 100 mg/L has been determined for the effects of the test substance on mortality of Oncorhynchus mykiss. 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.

Description of key information

LC50 (96 h) > 100 mg/L based on mortality of Oncorhynchus mykiss (EU Method C.1)

Additional information

One experimental study is available investigating the short-term toxicity of methyl-N-{[dimethoxy(methyl)silyl]methyl}carbamate (CAS 23432 -65 -7) to freshwater fish (Hertl, 2002). This study was performed according to EU Method C.1 (GLP). Oncorhynchus mykiss was exposed to a limit concentration of nominal 100 mg/L. Analysis of the dissolved organic carbon (DOC) revealed a mean recovery of 89%. Since the substance is expected to hydrolyse rapidly in contact with water (DT50: 1.9 h at 20 - 25 °C, pH 7), the result from this study mainly investigated the possible effects of the hydrolysis products (Methyl-N-{[dihydroxy(methyl)silyl]methyl}carbamate und methanol). After an exposure of 96 h no mortality was observed resulting in a LC50 of > 100 mg/L.