Triethoxyhexadecylsilane

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:

key study

Study period:

1989-12-12 to 1989-12-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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:

LC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

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 LC50 value of >1000 mg/L and NOEC 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.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please refer to the attached justification below and the overall justification for grouping of substances attached in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

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)

Description of key information

LL50 (96 h) > 1000 mg/L (nominal, OECD 203, Danio rerio) based on read-across from CAS 16415-12-6

Additional information

No data on the toxicity of triethoxy(hexadecyl)silane (CAS 16415-13-7) towards freshwater fish are available. In accordance with Regulation (EC) No. 1907/2006 Annex XI, 1.5 “Grouping of substances and read across” and in accordance with the read across assessment framework (RAAF, ECHA 2017) a read across from the analogue substance hexadecyl(trimethoxy)silane (CAS 16415-12-6) has been applied to support the environmental hazard assessment of the substance. Details on the read-across justification can be found in the attached justification in the respective target entry and in the overall justification for grouping of substances attached in IUCLID Section 13.

The study with the source substance hexadecyl(trimethoxy)silane (CAS 16415-12-6) was conducted according to a standard guideline (OECD 203) and to GLP. A LL50 (96 h) of >1000 mg/L and a NOELR (96 h) of ≥ 1000 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.

Based on the results of the analogue substance, triethoxy(hexadecyl)silane (CAS 16415-13-7) is not assumed to cause harmful effects towards fish.