Reaction products of [3-(2,3-epoxypropoxy)propyl]trimethoxysilane and triacetoxyvinylsilane.

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:

October 22 1999 to April 12 2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

low dissolved oxygen levels at 48 hrs may have contributed to some fish deaths.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

Adjustment of pH

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0, 100, 178, 316, 562 and 1000 ppm nominal
- Sampling method: Single 50 ml aliquots taken directly from each test chamber and analysed in triplicate the same day via ICP-OES
- Sample storage conditions before analysis: Not reported

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Test article was weighed directly into tared glass weighing caps which were then directly added into the individual test vessels and left in place for the duration of the study. Test article added to achieve duplicate concentrations of approximately 0, 100, 178, 316, 562 and 1000 ppm. Empty glass weighing caps were added onto the control vessels. Test solutions were briefly stirred to disperse the test article. Fish were added six to six and a half hours after test article added to test medium to allow for hydrolysis.
- Controls: Matrix blanks i.e. well water without product.
- Evidence of undissolved material: Not reported

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- Common name: Bluegill Sunfish
- Strain: Rafinesque
- Source: Northeastern Aquatics Inc., Rhinebeck, New York, September 1999
- Age at study initiation (mean and range, SD): Juvenile
- Length at study initiation (length definition, mean, range and SD): Average from 10 fish sacrificed prior to test initiation: 2.4 cm; range 2.1-2.7 cm
- Weight at study initiation (mean and range, SD): Average from 10 fish sacrificed prior to test initiation: 0.14 g/fish
- Feeding during test: None

ACCLIMATION
- Acclimation period: 12-14 days prior to test initiation
- Acclimation conditions (same as test or not): Maintained in continuous flowing (recirculation) laboratory water
- Type and amount of food: Harlan Teklab (Aquatic diet No. 1) commercial food and Sanders Great Salt Lake Artemia Cysts. Feeding discontinued 48 hours prior to test.
- Feeding frequency: Once daily except weekends and holidays
- Health during acclimation (any mortality observed): <5% mortality

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

Range 94 - 102 mg/L as CaCO3 from weekly well water measurements

Test temperature:

Range 20.7 - 20.9

pH:

Range 7.5-8.4. Note, pH of test vessels was readjusted daily to the approximate pH of the controls.

Dissolved oxygen:

Range 0.6 - 8.7. Note, Oxygen levels were very low (<60% saturation) at 48 hours in the 100, 178, 319 and one test vessel of the 565 ppm concentrations. Aeration system was changed from 48h to end of test (Pasteur aeration pipettes replaced by air stones and aeration rate increased); DO returned to 8.3-8.7 for remainder of study.

Nominal and measured concentrations:

Nominal: 0, 100, 178, 316, 562 and 1000 ppm
Measured: 0, 100, 178, 319, 565 and 997 ppm

Details on test conditions:

TEST SYSTEM
- Test vessel: 11 litre glass vessel
- Type (delete if not applicable): open / closed - loosely covered with Plexiglass
- Material, size, headspace, fill volume: Glass, 11 litre, filled with 10 L of laboratory well water
- Aeration: Yes
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- Biomass loading rate: <0.8 g fish/l

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Well water from 1809 Salzberg Road, Bay Co., MI. Water is pumped from the well, transported to the lab, adjusted to 22+/- 2°C and aerated before use.
- Total organic carbon: Not specified
- Particulate matter: Not specified
- Metals: Not specified
- Pesticides: Not specified
- Chlorine: Not specified
- Alkalinity: 180-182 mg/L as CaCO3
- Ca/mg ratio: Not reported
- Conductivity: 503-652 µmho/cm
- Culture medium different from test medium: Culture medium is recirculated and aerated well water, test medium is well water, aerated > 48 hrs prior to test article addition.
- Intervals of water quality measurement: Weekly

OTHER TEST CONDITIONS
- Adjustment of pH: Yes using 1N HCl
- Photoperiod: 16 h light, 8 h dark
- Light intensity: Cool white fluorescent light, 101 - 205 foot candles (1087-2206 lux).
FISH ADDED TO TEST VESSEL 6 TO 6.5 HOURS AFTER ADDITION OF TEST ARTICLE TO ALLOW TIME FOR HYDROLYSIS OF THE TEST ARTICLE.

EFFECT PARAMETERS MEASURED: not specified

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.78

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

345 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: described as hydrolysis product by study author

Basis for effect:

mortality (fish)

Remarks on result:

other: 300-397 95% CL

Details on results:

- Behavioural abnormalities: None reported
- Observations on body length and weight: None reported
- Other biological observations: None reported
- Mortality of control: No mortality
- Other adverse effects control: None reported
- Abnormal responses: None reported
- Any observations that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: No

Reported statistics and error estimates:

Trimmed Spearman Karber method

Sublethal observations / clinical signs:

Table 1: Test substance Concentrations (mg/L) Measured During Bluegill Study

Loading Level (mg/l)	Time = 0 hrs		Time = 48 hrs		Time = 96 hrs
	Chamber 1	Chamber 2	Chamber 1	Chamber 2	Chamber 1	Chamber 2
100	106	105	103	102	92	93
178	188	188	183	181	163	167
316	337	337	332	327	286	294
562	589	587	582	576	539	514
1000	1058	1040	1023	1012	932	914

Table 2: Statistical Results

Time Period (hours)	NOEC (mg/l)	LC50 (mg/l)	95% Confidence Interval (mg/l)
3	997	>997	ND
6	565	875	ND
24	178	389	355 -427
48	ND	345	300 -397
72	ND	345	300 -397
96	ND	345	300 -397

*ND = Not determinable

Table 3: Test System Observations

Concentration mg/l	Test Vessel #	Observations *
		0 -h	3 -h	6 -h	24 -h	48 -h	72 -h	96 -h
Control 0 ppm	1	10 N	10 N	10 N	10 N	10 N	10 N	10N
	2	10 N	10 N	10 N	10 N	10 N	10 N	9 N, 1 M
100 ppm	3	10 N	10 N	10 N	10 N	9 N, 1 D	9 N, 1 D	9 N, 1 D
	4	10 N	10 N	10 N	10 N	10 N	10 N	10 N
178 ppm	5	10 N	10 N	10 N	10 N	10 N	10 N	10 N
	6	10 N	10 N	10 N	10 N	9 N, 1 D	9 N, 1 D	9 N, 1 D
319 ppm	7	10 N	10 N	10 N	8 N, 2 D	7 N, 3 D	7 N, 3 D	7 N, 3 D
	8	10 N	10 N	10 N	9 N, 1 D	6 N, 4 D	6 N, 4 D	6 N, 4 D
565 ppm	9	10 N	10 N	10 N	10 D	10 D	10 D	10 D
	10	10 N	10 N	10 N	10 D	10 D	10 D	10 D
997 ppm	11	10 N	10 N	4 N, 5 D, 1 M	10 D	10 D	10 D	10 D
	12	10 N	10 N	1 N, 8 D, 1 M	10 D	10 D	10 D	10 D

* Observations are coded as: N = Normal, D = Dead, M = Moribund

Validity criteria fulfilled:

yes

Remarks:

Criteria for mortality in control was met. Dissolved oxygen levels were not maintained but there is adequate discussion of the possible impact of this so the study is not considered to be invalidated.

Conclusions:

A 96-h LC50 value of 345 mg/l has been determined for the effects of the test substance (CAS 154518-41-9) on mortality of the Bluegill Sunfish Lepomis macrochirus. A 96-h NOEC was not determined in the test. It is likely that the test organisms were exposed to a mixture of the parent substance and hydrolysis products.

Description of key information

Short-term toxicity to fish: 96 hour EC₅₀ 345 mg/l (measured (total Si), arithmetic mean) (OECD Guideline 203). It is not feasible to reinterpret this test result in terms of the silanol hydrolysis products.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

345 mg/L

Additional information

A 96-h EC₅₀ value of 345 mg/l (measured (based on total silicon), arithmetic mean) have been determined for the effects of reaction products of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and triacetoxyvinylsilane (CAS 154518-41-9) on mortality of Lepomis macrochirus. No NOEC value was determined in the test. In view of the test media preparation method/exposure regime it is likely that the test organisms were exposed predominantly to the hydrolysis products of the tested substance. It is not feasible to reinterpret this test result in terms of the silanol hydrolysis products.

The constituents of the registration substance hydrolyse rapidly (half-life <12 hours at pH 7 and 25°C) to [3-(2,3-epoxypropoxy)propyl]silanetriol, vinylsilanetriol, acetic acid/acetates and methanol.