Reaction mass of 4,4,13,13-tetraethoxy-3,14-dioxa-8,9-dithia-4,13-disilahexadecane and 4,4,14,14-tetraethoxy-3,15-dioxa-8,9,10-trithia-4,14-disilaheptadecane

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1991-12-02 to 1991-12-13

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The study was conducted according to an appropriate OECD test guideline, and in compliance with GLP, and was considered to be reliability 1 (reliable without restrictions). Read across to the registered substance is considered scientifically justified.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: Test media were prepared at nominal loading rates of 1000 and 10000 mg/L by adding appropriate amounts of the test substance to 1.5 litres of the dilution water and stirring for approximately 20 hours at a temperature of 25ºC. The resulting media were allowed to stand for 4 hours before introducing the fish. Fresh test media were prepared for daily renewal.

- Controls: Dilution water

- Evidence of undissolved material (e.g. precipitate, surface film, etc): It is likely that the solubility of the substance in the test medium was exceeded a
t the tested loading rates. Undissolved test substance was observed to be present in the test media.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM

- Common name: Zebrafish

- Source: Commercial hatchery; M.B. Ruysbroek B.V., Maassluis, Netherlands

- Length at study initiation (length definition, mean, range and SD): 2.1 +/-0.1 cm

- Weight at study initiation (mean and range, SD): 0.07 +/-0.01 g

- Feeding during test: none

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

96 h

Hardness:

204 mg/L

Test temperature:

24.3-25.6ºC

pH:

7.7-8.2

Dissolved oxygen:

≥5.6 mg/L

Nominal and measured concentrations:

Nominal loading rates: 0(Control), 1000 and 10000 mg/L.

It is likely that the solubility of the substance in the test medium was exceeded at the tested loading rates. Undissolved test substance was observed to be present in the test media.

Details on test conditions:

TEST SYSTEM

- Test vessel: Beaker

- Type (delete if not applicable): open

- Material, size, headspace, fill volume: glass, 2 litre with 1.5 litres of test medium

- Aeration: yes

- Renewal rate of test solution (frequency/flow rate): daily

- No. of organisms per vessel: 10

- No. of vessels per concentration (replicates): 2

- No. of vessels per control (replicates): 2

- Biomass loading rate: 0.5 g/L

TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: DSWL standard water prepared by adding salts to groundwater obtained from near Linschoten, Netherlands

- Total organic carbon: 1.7 mg/L

- Ca/Mg ratio: 1.32 mmol/L Ca2+ : 0.72 mmol/L Mg2+

- Culture medium different from test medium: no data

- Intervals of water quality measurement: daily

OTHER TEST CONDITIONS

- Adjustment of pH: no

- Photoperiod: 16 h light 8 h dark with 30 minute transition

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): mortality after 24, 48, 72 and 96 hours

TEST CONCENTRATIONS

- Spacing factor for test concentrations: 10

- Justification for using less concentrations than requested by guideline: not reported

- Range finding study: yes but results not reported

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOELR

Effect conc.:

>= 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: none

- Mortality of control: 0

- Other adverse effects control: none

- Effect concentrations exceeding solubility of substance in test medium: The solubility of the substance in the test medium (approximately 0.5 mg/l)was exceeded at the tested loading rates. Undissolved test substance was observed to be present in the test media.

Reported statistics and error estimates:

There were no effects in any treatment. Statistically analysis of the results was therefore not required.

Sublethal observations / clinical signs:

There were no toxic effects in either treatment.

Validity criteria fulfilled:

yes

Conclusions:

A 96-hour LL50 value of >10000 mg/L and NOELR of ≥10000 mg/L have been determined for the effects of the test substance on mortality of Brachydanio rerio. Undissolved material was observed to be present in the exposure media prepared for the test.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1998-10-18 to 1998-10-23

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The study was conducted according to an appropriate OECD test guideline, and in compliance with GLP, and was considered to be reliability 1 (reliable without restrictions). Read across to the registered substance is considered scientifically justified.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Analysis of test medium was not conducted in a GLP laboratory

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Control and 1000 mg/L

- Sampling method: A sample of freshly prepared and 24 hour-old test medium was taken for analysis.

- Sample storage conditions before analysis: no data

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: Suspensions of the test substance were prepared at loading rates of 10, 100 and 1000 mg/L by weighing the test substance onto small polyethylene platelets and transferring these to the media preparation vessels (5 litre polyethylene flasks). The appropriate volume of dilution water was added and then the flask contents were then shaken (130 rpm) for 20 hours. The vessels were then transferred into a constant temperature water bath before introducing the fish.

- Controls: Dilution water

- Evidence of undissolved material: undissolved test material was observed to be present in the test vessels.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM

- Common name: Zebra fish

- Source: Aquafarm Ryba, Zeven, Germany

- Length at study initiation: approximately 3 cm

ACCLIMATION

- Acclimation period: no data

- Acclimation conditions (same as test or not): no data

- Type and amount of food: no data

- Feeding frequency: no data

- Health during acclimation (any mortality observed): no data

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

no data

Test temperature:

24.7-25.0ºC

pH:

6.8-8.2-8.0

Dissolved oxygen:

7.7-8.0 mg/L

Nominal and measured concentrations:

Nominal concentrations: 0(Control), 10, 100 and 1000 mg/L.

The measured concentrations of test substance in the 1000 mg/L treatment measured on one occasion ranged between 185-220 mg/L in fresly prepared medium and 64-150 mg/L in 24-h old medium. These concentrations exceed the solubility of the test substance. The test results are presented and interpreted with reference to nominal loading rate.

Details on test conditions:

TEST SYSTEM

- Test vessel: Flask

- Type: open

- Material, size, fill volume: Polyethylene, 5 litre with 5 litre fill volume

- Aeration: yes

- Renewal rate of test solution (frequency/flow rate): daily

- No. of organisms per vessel: 3 fish in 10 and 100 mg/L treatments, 7 fish in 1000 mg/L treatment and Control

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

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

TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: Drinking water consistent with OECD 203 test guideline

- Intervals of water quality measurement: Daily

OTHER TEST CONDITIONS

- Adjustment of pH: adjusted to pH 7.0 twice per day using 1M HCl

- Photoperiod: no data

- Light intensity: no data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): mortality after 24, 48, 72 and 96 hours.

TEST CONCENTRATIONS

- Spacing factor for test concentrations: 10

- Justification for using less concentrations than requested by guideline: the test design was a combined range-finding and limit test

- Range finding study: yes

- Test concentrations: 10, 100 and 1000 mg/L loading rates

- Results used to determine the conditions for the definitive study: no effects at 1000 mg/L

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOELR

Effect conc.:

>= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Mortality of control: 0

- Effect concentrations exceeding solubility of substance in test medium: Test media were dispersions and undissolved test material was observed to be present.

Reported statistics and error estimates:

No toxic effects were observed in the test and therefore statistical analysis of the results was not required.

Sublethal observations / clinical signs:

No effects were observed in the test

Validity criteria fulfilled:

yes

Conclusions:

A test medium prepared at a nominal loading rate 1000 mg/L of the test substance was not acutely toxic to Brachydanio rerio over 96 hours (96-h LL50: >1000 mg/L). A NOELR of ≥1000 mg/L was determined in the same test. Undissolved material was observed to be present in the exposure media prepared for the test.

Description of key information

Short-term toxicity to fish: 96 hr LL₅₀ >1000 mg/l (nominal) (highest concentration tested) (OECD Guideline 203 (Fish, Acute Toxicity Test)), read across from an analogous/structurally related substance, 4,4,13,13-tetraethoxy-3,14-dioxa-8,9-dithia-4,13-disilahexadecane, S2 (CAS 56706-10-6).

Additional information

No data are available for short-term toxicity of the registration substance to fish. This endpoint is therefore fulfilled by weight of evidence from reliable data for two related substances 4,4,13,13-tetraethoxy-3,14-dioxa-8,9-dithia-4,13-disilahexadecane (S2 constituent, CAS 56706-10-6)) and polysulfides, bis[3-(triethoxysilyl)propyl] (CAS 211519-85-6; containing S2, S3 and S4 constituents). No effects were observed in tests conducted with these substances at treatment levels of 1000 (Institut Fresenius, 1998a) and 10000 mg/l (TNO, 1992) respectively.

Based on this approach, the short-term LL₅₀ value for fish for the registration substance is judged to be >1000 mg/l. In this study (Institut Fresenius, 1998a) the organisms would have been continuously exposed to <1 mg/l of parent substance in solution because the test medium was saturated with the substance. Undissolved material was observed to be present in the exposure media prepared for both tests and the test conditions can be considered as worst case.

During the tests with the source substances, test organisms are expected to have been exposed to a mixture of the parent substance, undissolved tests material, the hydrolysis products of the test substance and aggregated hydrolysis product.

The 96-hour LL₅₀ value of >1000 mg/l is considered to be the appropriate value for the registration substance. This value is above the water solubility of the parent registration substance.