Triethoxypropylsilane

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

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 justification for grouping of substances provided in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

80 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

58 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Conclusions:

A 96-hour LC50 value of 80 mg/L and NOEC of 58 mg/L have been determined for the effects of the test substance on mortality of Brachydanio rerio.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1994-01-10 to 1994-01-14

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

Analytical monitoring:

yes

Details on sampling:

Test substance concentrations were measured in fresh and old test media in which there were surviving at the start of the test and then after 24, 48 and 72 hours exposure periods.

Vehicle:

no

Details on test solutions:

A stock solution of the test substance was prepared at a nominal concentration of 1000 mg/L by mixing for 18 hours followed by filtration. Treatments were prepared by dilution of the stock solution.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM

- Common name: Zebrafish

- Source: West aquarium, Bad Lauterberg, Germany

- Length at study initiation (length definition, mean, range and SD): 3.0 cm +/-0.5 cm

- Feeding during test: none


ACCLIMATION

- Acclimation period: at least 14 days

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

- Type and amount of food: TetraMin® at 1% of body weight

- Feeding frequency: Daily

- Health during acclimation (any mortality observed): The fish exhibit normal behaviour and are free from visible signs of disease at the start of the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

12.8 ºdH

Test temperature:

20 - 21ºC

pH:

7.4 - 8.3

Dissolved oxygen:

0.4 - 8.9 mg/L

Low dissolved oxygen concentrations were only recorded in test vessels containing dead fish. Measured dissolved concentrations in treatments (34, 58 and 94 mg/L) where there was 100% fish survival over at least some 24 hour exposure periods were always in the range 5.8-8.5 mg/L. Judging from the measured dissolved oxygen concentrations prior to fish deaths, the low concentrations are therefore not considered to be a cause of the fish deaths but rather a consequence of the presence of the dead fish.

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal concentrations: 0 (Control) and 6, 10, 17, 28 and 50% dilutions of the stock solution.

Corresponding geometric mean measured concentrations were: 0 (Control), 34, 58, 94, 173 and 299 mg/L.

Details on test conditions:

TEST SYSTEM

- Test vessel:

- Type: open aquarium

- Material, size, headspace, fill volume: 30 litre

- Aeration: Continuous

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

- No. of organisms per vessel: 10

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

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

- Biomass loading rate: 0.4 g/l


TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: Potable water from Gelsenwasser AG


OTHER TEST CONDITIONS

- Adjustment of pH: None

- 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.:

80 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

58 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Mortality of control: 0

Reported statistics and error estimates:

The methods of determining the LC50 and LC0 (NOEC) values are not reported. However a dose-response curve is presented showing the LC50 value.

Sublethal observations / clinical signs:

Table 1. Results of analysis of test media.

 

Nominal treatment (% stock solution)	Measured concentration at start of test (mg/L)	Measured concentration in old/fresh media at 24 hours	Measured concentration in old/fresh media at 48 hours	Measured concentration in old/fresh media at 72 hours	Measured concentration in old media at 96 hours	Geometric mean measured concentration (mg/L)
0 (Control)	-	-	-	-	-	-
6	40	31/36	28/41	31/41	25	34
10	79	47/53	57/64	46/70	51	58
17	121	89/94	74/106	81/112	79	94
28	191	157/-	-/-	-/-	-	173
50	329	272/-	-/-	-/-	-	299

 

Table 2. Test results

 

Nominal treatment (% stock solution)	Cumulative mortality after 24 hours (%)	Cumulative mortality after 48 hours (%)	Cumulative mortality after 72 hours (%)	Cumulative mortality after 96 hours (%)
0 (Control)	0	0	0	0
6	0	0	0	0
10	0	0	10	10
17	0	50	50	70
28	100	100	100	100
50	100	100	100	100

 

Conclusions:

A 96-hour LC50 value of 80 mg/L and NOEC of 58 mg/L have been determined for the effects of the test substance on mortality of Brachydanio rerio.

Description of key information

LC50(96h): 80 mg/l (Brachydanio rerio, EU method C.1, read across from CAS 5089-70-3)

Additional information

Note: In order to support the read across from (3-chloropropyl) triethoxysilane (CAS 5089-70-3) to triethoxy(propyl)silane (CAS 2550-02-9) an OECD 203 is currently ongoing. The dossier will be updated accordingly once the final report is available.

Measured data were not available for triethoxy(propyl)silane (CAS 2550-02-9). It was considered appropriate to read across from the structurally analogous substance, (3-chloropropyl) triethoxysilane (5089-70-3).

A 96-hour LC50value of 80 mg/l and NOEC of 58 mg/l have been determined for the effects of the test substance on mortality of Brachydanio rerio based on a guideline study (EU method C.1 acute toxicity to fish, Hüls 1995).

The results are interpreted with reference to mean measured concentrations of the test substance.

Additional good quality data for the analogue substance, trimethoxy(propyl)silane (CAS 1067-25-0), have been read across for triethoxy(propyl)silane. Both substances share the same silanol hydrolysis product, propylsilanetriol; the other hydrolysis products being ethanol and methanol. A 96 hr LC50 of >746 mg/l (EU Method C.1 (Acute Toxicity for Fish) was determined for the effects of trimethoxy(propyl)silane (CAS 1067-25-0) on mortality of Brachydanio rerio based on mean measured concentrations.