acrylic acid, 3-(trimethoxysilyl)propyl ester

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:

20 March to 24 March 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

Previous version (1992)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OTS 797.1400 (Fish Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control and all test concentrations
- Sampling method: Water samples were taken and extracted immediately upon preparation. No further details on sampling provided

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Test material was prepared by direct dispersion in water. 20 g was dispersed in dechlorinated tap water with the aid of ultrasonic disruption and shaking and the volume adjusted to 5 litres to give a 4.0 g/l aqueous stock solution. Aliquots of this stock solution were added to dechlorinated tap water to give the test series.
- Eluate: not reported
- Differential loading: no
- Controls: dechlorinated tap water
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): None reported
- Other relevant information: None

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Strain: not reported
- Source: Donnington Fish Farm, Upper Swell, Gloucester, U.K.
- Age at study initiation (mean and range, SD): not reported
- Length at study initiation (length definition, mean, range and SD): mean = 4.4 cm (SD 0.1 cm)
- Weight at study initiation (mean and range, SD): 0.46 g (SD 0.05 g)
- Method of breeding: not reported
- Maintenance of the brood fish: not reported

ACCLIMATION
- Acclimation period: 7 days
- Acclimation conditions (same as test or not): same as test
- Type and amount of food during acclimation: fish were fed commercial trout pellets
- Feeding frequency during acclimation: not reported, however, feeding was stopped 48 hours prior to the start of the test
- Health during acclimation (any mortality observed): <1% mortalities


FEEDING DURING TEST - fish were not fed during test

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

approximately 112 mg/l as CaCO3

Test temperature:

14 +/- 1 degrees C

pH:

7.3-7.4

Dissolved oxygen:

9.2 - 10.1

Salinity:

Not reported

Conductivity:

Not reported

Nominal and measured concentrations:

Nominal: control, 10, 18, 32, 56 and 100 mg/l
Measured: see results section (high variation between samples measured at 0 h, 24 h and 96 h).

Details on test conditions:

TEST SYSTEM
- Test vessel: 20 L glass vessels
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: glass, 20 L
- Aeration: not reported
- Renewal rate of test solution (frequency/flow rate): test solution was renewed every 24 hours, no further details reported
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- Biomass loading rate: 0.23 g bodyweight /L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated tap water
- Total organic carbon: Typical TOC from tests conducted on tap water from 1/1/1994 - 31/12/1994: 1.8 mg/l
- Particulate matter: not reported
- Metals: Many metals analysed from tests conducted on tap water from 1/1/1994 - 31/12/1994, none were found in excessive concentrations.
- Pesticides: Typical total pesticides from tests conducted on tap water from 1/1/1994 - 31/12/1994: <0.03 µg/l
- Chlorine: Typical water total chlorine from tests conducted on tap water from 1/1/1994 - 31/12/1994: 0.23 mg/l
- Alkalinity: Typical water alkalinity from tests conducted on tap water from 1/1/1994 - 31/12/1994: 104 mg/l
- Ca/mg ratio: not reported
- Conductivity: Typical water conductivity from tests conducted on tap water from 1/1/1994 - 31/12/1994: 374 M/CSM
- Hardness: Typical water hardness from tests conducted on tap water from 1/1/1994 - 31/12/1994: 175 mg CaCO3 /l
- Salinity: not reported
- Culture medium different from test medium: no
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Adjustment of pH: adjusted to 7.5
- Photoperiod: 16 hours light : 8 hours dark
- Light intensity: not reported

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality and behaviour

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Justification for using less concentrations than requested by guideline: not applicable
- Range finding study
- Test concentrations: One range finding study was conducted with the test concentrations of 1.0, 10 and 100 mg/l as a static test. Another range-finding study was conducted at 10 and 100 mg/l using flow through conditions. A final range-finding study used the test concentrations of 32 and 100mg/l and used an auxiliary solvent.
- Results used to determine the conditions for the definitive study: The first study showed mortalities at 100 mg/l. The second showed mortalities at 100 mg/l and none at 10 mg/l. The flow-through method was inappropriate due to a globule of test material forming, therefore a semi-static method was selected for the definitive study. The third resulted in precipitate, therefore a solvent was not used in the definitive test.

Reference substance (positive control):

not specified

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

24 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% C.I. 18-32 mg/l (based on the concentrations resulting in 0 and 100% mortality respectively)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.9 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% C.I. 1.5-2.4 mg/l

Remarks:

based on measured test solutions at 24h

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

1.5 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: based on measured test solutions at 24h

Details on results:

- Behavioural abnormalities: behaviour was observed and responses occurred at concentrations of > 18 mg/l. These included loss of equilibrium, swimming at the surface and swimming at the bottom of the test vessels.
- Observations on body length and weight: not measured
- Other biological observations: see Results
- Mortality of control: 0% after 96 hours
- Other adverse effects control: none reported
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: none reported
- Effect concentrations exceeding solubility of substance in test medium: none reported

Reported statistics and error estimates:

LC50 values and confidence limits were calculated by the moving average method of Thompson 1947

Sublethal observations / clinical signs:

Table 1. Cumulative mortality in the first range-finding study (static conditions)

Nominal concentration (mg/l)	Cumulative mortality
	24h	48h	72h	96h
Control	0	0	0	0
1.0	0	0	0	0
10	0	0	0	0
100	1*	3	3	3

*loss of equilibrium and swimming at bottom

Table 2. Cumulative mortality in the second range-finding study (flow-through conditions)

Nominal concentration (mg/l)	Cumulative mortality
	24h	48h	72h	96h
Control	0	0	0	0
10	0	0	0	0
100	0*	3	3	3

* Hyperactive swimming

Table 3. Cumulative mortality in the definitive exposure

Nominal concentration (mg/l)	Replicate	Cumulative mortality
		3h	6h	24h	48h	72h	96h
Control	1	0	0	0	0	0	0
	2	0	0	0	0	0	0
10	1	0	0	0	0	0	0
	2	0	0	0	0	0	0
18	1	0	0	0	0	0	0
	2	0	0	0	0	0	0
32	1	0	0	0	0	1	10
	2	0	0	0	0	1	10
56	1	0	0	0	10	10	10
	2	0	0	0	10	10	10
100	1	0	0	10	10	10	10
	2	0	0	10	10	10	10

Table 4. Behavioural observations in the definitive study

Nominal concentration (mg/l)	Replicate	Behavioural responses	Time
			3h	6h	24h	48h	72h	96h
Control	1	None detected
	2	None detected
10	1	None detected
	2	None detected
18	1	None detected
	2	None detected
32	1	Swimming at surface Loss of equilibrium Swimming at bottom				10/10	2/9   7/9	All dead
	2	Swimming at surface Loss of equilibrium Swimming at bottom				6/10	3/9   6/9	All dead
56	1	Swimming at surface		6/10	6/10	All dead	All dead	All dead
	2	Swimming at surface		6/10	6/10	All dead	All dead	All dead
100	1	Swimming at surface Loss of equilibrium		8/10   2/10	All dead	All dead	All dead	All dead
	2	Swimming at surface Loss of equilibrium		8/10   2/10	All dead	All dead	All dead	All dead

Table 4. Verification of test concentrations in the definitive study

Samples	Nominal concentration (mg/l)	Measured concentration (mg/l)	% of nominal concentration
0 hours (fresh media)	Control	<LOD	-
	10	10.2	102
	18	17.5	97
	32	30.8	96
	56	52.0	93
	100	88.1	88
24 hours (expired media)	Control	<LOD	-
	10	1.13	11
	18	2.07	11
	32	2.81	9
	56	5.67	10
	100	10.3	10
96 hours (expired media)	Control	<LOD	-
	10	0.545	5
	18	0.973	5
	32	1.89	6

Validity criteria fulfilled:

yes

Remarks:

Analytical measurement of the test concentrations was conducted; mortality was 0% in the control group and dissolved oxygen was approximately 100% of air saturation value (as calculated by reviewer)

Conclusions:

A 96-hour LC50 value of 24 mg/l was reported for the effects of the 3-(trimethoxysilyl)propyl acrylate on the mortality of Oncorhynchus mykiss in a semi-static test, based on measured concentrations.

Description of key information

96-hour: LC₅₀ 24 mg/l based on the mortality of Oncorhynchus mykiss, based on nominal concentrations. The LC₅₀ is equivalent to 19.7 mg/l when expressed in terms of concentration of the silanol hydrolysis product, 3-acryloxypropylsilanetriol.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

19.7 mg/L

Additional information

A 96-hour LC₅₀ value of 24 mg/l based on the mortality of Oncorhynchus mykiss was determined in a reliable guideline study, conducted under semi-static conditions with the registration substance, 3-(trimethoxysilyl)propyl acrylate (CAS 4369-14-6, EC 419-560-6), in accordance with OECD Test Guideline 203. A NOEC value of 18 mg/l was also determined in the same study. Gas chromatography analysis determined concentrations of the parent test substance were within 80-120% of nominal values at 0 hours, however only 5% of the nominal concentrations was detected after 96 hours. This is considered to reflect the loss of the parent substance due to hydrolysis. The results are therefore expressed in terms of the nominal concentrations of the test substance.

The test substance is subject to rapid hydrolysis and under the test conditions it is therefore likely that exposure will have been to its hydrolysis products (3-acryloxypropylsilanetriol and methanol).

The results may be expressed in terms of concentration of the silanol hydrolysis product, 3-acryloxypropylsilanetriol, by applying a molecular weight correction: (MW of silanol = 192.25 / MW of parent = 234.33) * [Concentration of parent = 24 mg/l] = 19.7 mg/l

There is no basis to expect that methanol significantly influences the results of the test. The toxicity of methanol is discussed further in Section 6.1 Aquatic Toxicity endpoint summary of IUCLID.