Hexadecyltrimethoxysilane

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:

1989-12-12 to 1989-12-16

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: 1.5 g of test substance was added to 1.5 L of dilution water and stirred vigorously for 24 hours on a magnetic stirrer at a temperature of 25+/1ºC. The aqueous phase was then decanted into the test vessel as the test medium.

- 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. An oil-like substance was observed on the surface of the test media.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM

- Common name: Zebrafish

- Source: obtained from a commercial hatchery; M.B. Ruysbroek B.V., Maassluis, The Netherlands.

- Length at study initiation (length definition, mean, range and SD): 2.2+/-0.1 cm

- Weight at study initiation (mean and range, SD): 0.08+/-0.01 g

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

215 mg/l as CaCO3

Test temperature:

25+/-1ºC

pH:

7.6-8.0

Dissolved oxygen:

6.1-8.5 mg/L

Salinity:

not applicable

Nominal and measured concentrations:

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

It is likely that the solubility of the substance in the test medium was exceeded. An oil-like substance was observed on the surface of the test media.

Details on test conditions:

TEST SYSTEM

- Test vessel: beaker

- Type (delete if not applicable): open

- Material, size, fill volume: glass, 2 L with 1.5 L fill volume

- Aeration: none

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

- No. of organisms per vessel: 10

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

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

- Biomass loading rate: 0.52 g/L

TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: Synthetic freshwater (DSWL) prepared by the additional of salts to groundwater from near Linschoten, The Netherlands.

- Culture medium different from test medium: no

- Intervals of water quality measurement: Daily

OTHER TEST CONDITIONS

- Adjustment of pH: no

- Photoperiod: 16 h light, 8 h dark

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

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:

- Behavioural abnormalities: 0
- Mortality of control: 0
- Other adverse effects control: 0
- Abnormal responses: 0
- Effect concentrations exceeding solubility of substance in test medium: It is likely that the solubility of the substance in the test medium was exceeded. An oil-like substance was observed on the surface of the test media.

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 toxic effects were observed in the test.

Validity criteria fulfilled:

yes

Conclusions:

A 96-h LL50 value of >1000 mg/L and NOELR of ≥1000 mg/L have been determined for the effects of the test substance on mortality of Brachydanio rerio based on nominal loading rate of the test substance.

Description of key information

LL50 (96 h) > 1000 mg/L (nominal, OECD 203, Danio rerio)

Additional information

One limit test is available with the substance hexadecyl(trimethoxy)silane (CAS No. 16415-12-6) testing the short term toxicity towards fish according to a standard guideline (OECD 203) and GLP. The study was conducted under semi-static conditions and Danio rerio was used as the test organism. An LL50 (96 h) value of >1000 mg/L and a NOELR (96 h) value of ≥ 1000 mg/L revealing that no short term effects arise from the substance towards fish.