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Short-term toxicity to fish

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Endpoint:
short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1994-04-26 to 1994-04-30
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
EU Method C.1 (Acute Toxicity for Fish)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Analytical monitoring:
not specified
Details on sampling:
- Concentrations: 500 mg/L

- Sampling method: Samples of test media were taken from all treatments at the start and end of the first (0-24h) and third (48-72h) test periods.

- Sample storage conditions before analysis: refrigerated
Vehicle:
not specified
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: A stock solution was prepared by mixing the substance overnight with dilution water used in the test

- Controls: Dilution water
Test organisms (species):
Danio rerio (previous name: Brachydanio rerio)
Details on test organisms:
TEST ORGANISM

- Common name: Zebrafish

- Source: Tropical Waters (Feltham, UK)

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

- Length at study initiation (length definition, mean, range and SD): 3.4 cm (3.1 - 3.7 cm)

- Weight at study initiation (mean and range, SD): 0.38 g (0.3 - 0.45 g)

- Feeding during test: None

ACCLIMATION

- Acclimation period: 12 days

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

- Type and amount of food: TetraMin® Tropical Flake

- Feeding frequency: dependent upon size and temperature

- Health during acclimation (any mortality observed): Cumulative mortality must no exceed 5% in the 7-day period prior to the test.
Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
96 h
Hardness:
40.8 - 41.3 mg/L
Test temperature:
20 - 21ºC
pH:
7.0 - 7.5
Dissolved oxygen:
62 - 100% ASV
Nominal and measured concentrations:
Nominal: Control, 31.25, 62.5, 125, 250 and 500 mg/L.

Measured concentrations in fresh media (excluding Control) at start of test: 27.2, 58.5, 119, 249 and 499 mg/L.

Measured concentrations in old media (excluding Control) after 24 h exposure: 30.7, 63.4, 124, 248 and 497 mg/L.

Measured concentrations in fresh media (excluding Control) at 48 h: 32, 64.6, 124, 241 and 490 mg/L.

Measured concentrations in old media (excluding Control) after 24 h exposure: 28.1, 59.9, 117, 232 and 492 mg/L.

Mean measured concentrations: 29.4, 61.5, 121, 242 and 494 mg/L.

Mean measured concentrations as a % of nominal: 94.1, 98.4, 96.6, 96.9 and 98.9.
Details on test conditions:
TEST SYSTEM

- Test vessel: Culture vessels

- Type: sealed

- Material: Glass

- Aeration: none

- Renewal rate of test solution (frequency): daily

- No. of organisms per vessel: 10

- No. of vessels per concentration (replicates): 1

- No. of vessels per control (replicates): 1

- Biomass loading rate: 0.38 g/L

TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: Laboratory mains supply

- Chlorine: <0.1 mg/L (Total)

- Alkalinity: 14 mg/L CaCO3

- Conductivity: 128 μS/cm

- Culture medium different from test medium: no

- Intervals of water quality measurement:

OTHER TEST CONDITIONS

- Adjustment of pH: no

- Photoperiod: 16 h (light)/8 h (dark)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS

- Spacing factor for test concentrations: 2.0
Reference substance (positive control):
no
Key result
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 500 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks:
but exposure is to hydrolysis product
Basis for effect:
mortality
Duration:
96 h
Dose descriptor:
NOEC
Effect conc.:
>= 500 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks:
but exposure is to hydrolysis product
Basis for effect:
mortality
Details on results:
- Behavioural abnormalities: At the end of the testfish exposed to the 250 mg/L nominal test concentration were showing mild behavioural effects and those exposed to 500 mg/L severe behavioural effects.
Reported statistics and error estimates:
There were no lethal effects at the highest test concentration and therefore statistical analysis of the results was not carried out.
Validity criteria fulfilled:
yes
Conclusions:
A 96-hour LC50 value of >500 mg/L and NOEC of ≥500 mg/L have been determined for the effects of the test substance on mortality of Brachydanio rerio based on nominal concentration of the substance. However it is likely that the test organisms were primarily exposed to the hydrolysis products of the substance.
Endpoint:
short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
Not reported
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Principles of method if other than guideline:
No guideline specified.
GLP compliance:
not specified
Analytical monitoring:
not specified
Vehicle:
not specified
Details on test solutions:
no data
Test organisms (species):
Lepomis macrochirus
Details on test organisms:
no data
Test type:
not specified
Water media type:
freshwater
Remarks on exposure duration:
no data
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
not specified
Conc. based on:
test mat.
Remarks:
but exposure is to hydrolysis products
Basis for effect:
mortality
Conclusions:
An LC50 value of >1000 mg/L has been reported for the test substance to Lepomis macrochirus. The result is reported in a peer reviewed secondary source.. It is likely that the test organisms were exposed to hydrolysis products of the substance.
Endpoint:
short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
Not reported
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Principles of method if other than guideline:
No guideline specified.
GLP compliance:
not specified
Analytical monitoring:
not specified
Vehicle:
not specified
Test organisms (species):
Fundulus heteroclitus
Test type:
not specified
Water media type:
not specified
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
not specified
Conc. based on:
other: hydrolysis products
Basis for effect:
mortality
Conclusions:
An LC50 value of >1000 mg/L has been reported for the test substance to Fundulus heteroclitus. The result is reported in a peer reviewed secondary source, however there is insufficient information to fully assess its reliability.
Endpoint:
short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
No reported
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Principles of method if other than guideline:
No guideline specified.
GLP compliance:
not specified
Analytical monitoring:
not specified
Vehicle:
not specified
Test organisms (species):
Oncorhynchus mykiss (previous name: Salmo gairdneri)
Details on test organisms:
No data
Test type:
not specified
Water media type:
freshwater
Limit test:
no
Hardness:
no data
Test temperature:
no data
pH:
no data
Dissolved oxygen:
no data
Salinity:
no data
Nominal and measured concentrations:
no data
Details on test conditions:
no data
Reference substance (positive control):
not specified
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
400 mg/L
Nominal / measured:
not specified
Conc. based on:
test mat.
Remarks:
but exposure is to hydrolysis products
Basis for effect:
mortality
Reported statistics and error estimates:
Not reported
Conclusions:
An LC50 value of 400 mg/L has been reported for the test substance to Oncorhynchus mykiss. The result is reported in a peer reviewed secondary source. It is likely that the test organisms were exposed to hydrolysis products of the substance.
Endpoint:
short-term toxicity to fish
Type of information:
calculation (if not (Q)SAR)
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The result was obtained by an appropriate predictive method
Principles of method if other than guideline:
The ECOSAR ‘neutral organics’ QSARs for acute data have been applied and the effect concentrations calculated using log Kow and molar mass as input variables. An additional factor of *0.2 has been applied to the results.

The USEPA model ECOSAR was used as the basis for the estimation. This method is well-validated for ‘neutral organics’, i.e. those which act by a general narcotic mechanism, the potency of which is usually related to log Kow. Its scope is acute and long-term effects for the three standard trophic levels.
The method was validated for use with organosilicon compounds with a high weight percent of Si and limited or no additional functionality. Many of the reliable data for the category are limit values, therefore, the data were considered in terms of the range of the E(L)C50, in accordance with normal classification bands:    

E(L)C50 < 1 mg/l;
E(L)C50 in the range > 1 mg/l to 10 mg/l;
E(L)C50 in the range > 10 mg/l to 100 mg/l;
E(L)C50 > 100 mg/l.

In general ECOSAR predicted correctly for most substances for each trophic level. However, performance was improved significantly by application of a factor of 0.2 to each predicted value (expressed in mg/l). The organosilicon substances are slightly more toxic than the general ECOSAR ‘neutral organics’ regression lines, although still well within the range of each model. The factor of 0.2 is applicable to fish, Daphnia and algae, across the whole range of log Kowvalues. It is concluded that the acute effects of the substances in the sub-category can therefore be predicted from ECOSAR, with a minor modification.
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
10 000 mg/L
Conclusions:
A 96 h LC50 value of 10000 mg/L was obtained for the hydrolysis product of the submission substance using an appropriate calculation method. The results are considered to be reliable.

Description of key information

(96-hour) LC50: >500 mg/l mortality Danio rerio, reliability 1.
(96-hour) LC50: 10000 mg/l mortality, hydrolysis product (using an appropriate calculation method), reliability 2.

Key value for chemical safety assessment

Additional information

A 96-hour LC50 value of >500 mg/l and NOEC of ≥500 mg/l have been determined for the effects of the test substance on mortality of Danio rerio (tested as Brachydanio rerio) based on nominal concentration of the substance. The study was conducted according to a standard guideline (EU Method C.1, Acute Toxicity for Fish) and to GLP and so was selected as key study (1994).

LC50 values in the range of 400 to >1000 mg/l are available from secondary literature (three studies) of lower reliability. However, as the substance rapidly hydrolyses (half-life of approximately 5.5 hours) to methylsilanetriol, it is very likely that the test organisms were primarily exposed to the hydrolysis product retained in the test media. A 96 hour LC50 of 10000 mg/l for fresh water fish was derived for the hydrolysis product using an appropriate calculation method (QSAR adapted from ECOSAR v1.00) for silicon substances (2011).