acrylic acid, 3-(trimethoxysilyl)propyl ester

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21 March - 23 March 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Previous version (1984)

Deviations:

yes

Remarks:

Hardness (109 mg/l) was lower than the recommended range (140-250 mg/l). Stability tests indicated the parent substance is not stable, however static conditions were used.

Qualifier:

according to guideline

Guideline:

EPA OTS 797.1300 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control and 100 mg/l
- Sampling method: replicates 1 and 2 were pooled, and 3 and 4
- Sample storage conditions before analysis:

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: test material was dispersed in dechlorinated tap water with the aid of shaking and ultrasonic disruption. Volume was adjusted to 2 litres to give the 100 mg/l test concentration. pH adjusted to 7.5.
- Eluate: Not reported
- Differential loading: No
- Controls: dechlorinated tap water
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): In preliminary tests, a 100 mg/l test concentration solution was prepared by direct mixing of the undiluted test material and mixed thoroughly in a glass mixing vessel by magnetic stirrer.
- Other relevant information:

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Not reported
- Method of breeding: Culture conditions ensured reproduction by parthenogenesis. Gravid adults were isolated 24 hours prior to the initiation of the test
- Source: Institut National de Recherche Chimique Appliquee
- Age of parental stock (mean and range, SD): Not reported
- Feeding during test : daphnids were not fed during the test.

ACCLIMATION : not reported

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

109 mg/l as CaCO3

Test temperature:

21 degrees C (+/- 0 degrees)

pH:

7.5 - 7.6

Dissolved oxygen:

7.9 - 8.4 mg O2/l

Salinity:

Not reported

Conductivity:

Not reported

Nominal and measured concentrations:

Nominal: control and 100 mg/l
Measured: control and 84 (pooled replicates 1 and 2) and 97 (pooled replicates 3 and 4) mg/l at 0 h. Analysis of test solutions at 48 hours showed a marked decline in measured test concentrations and no parent substance was detected. See results section for further details.

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 ml glass stoppered conical flasks
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: glass, 250 ml, fill volume was 250 ml
- Volume of solution: 250ml
- Aeration: not reported
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 2

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
- Salinity: not reported
- Culture medium different from test medium: no
- Intervals of water quality measurement: 0, 24 and 48 hours

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

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mobility, other adverse reactions were recorded at 24 and 48 hours.

VEHICLE CONTROL PERFORMED: no - no vehicle used

RANGE-FINDING STUDY
- Test concentrations: 0.10, 1.0, 10, 100 mg/l in static conditions. 10 and 100 mg/l in flow through conditions
- Results used to determine the conditions for the definitive study: No immobilisation found in any concentration. Test material formed a large globule under the flow through conditions so the static conditions were selected for the definitive study.

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: None reported
- Observations on body length and weight: not measured
- Other biological observations: None reported
- Mortality of control: No mortality in any treatment
- Other adverse effects control: Not reported
- Immobilisation of control: No immobilisation in any treatment
- Abnormal responses: 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: A large globule of test material formed in the range finding study in flow through conditions. However, no evidence of the test concentrations exceeding the solubility of the test substance in the definitive, static study was found.

Reported statistics and error estimates:

EC50 values were given by inspection of the immobilisation data

Table 1. Cumulative immobilisation in the static, range-finding study

Nominal concentration (mg/l)	Cumulative immobilised Daphnia (out of 10 organisms per replicate)
	24 hours	48 hours
Control	0	0
0.10	0	0
1.0	0	0
10	0	0
100	0	0

Table 2. Cumulative immobilisation in the flow-through, range-finding study

Nominal concentration (mg/l)	Cumulative immobilised Daphnia (out of 10 organisms per replicate)
	24 hours	48 hours
Control	0	0
10	0	0
100	0	0

Table 3. Cumulative immobilisation in the definitive study

Nominal concentration (mg/l)	Replicate number	Cumulative immobilised Daphnia (out of 10 organisms per replicate)
		24 hours	48 hours
Control	1	0	0
	2	0	0
100	1	0	0
	2	0	0
	3	0	0
	4	0	0

Table 4. Verification of the test concentrations in the definitive study

Samples	Nominal concentration (mg/l)	Measured concentration (mg/l)	% of nominal concentration
0 hours	100 replicates 1+2	96.6	97
	100 replicates 3+4	84.1	84
48 hours	100 replicates 1+2	<LOD	-
	100 replicates 3+4	<LOD	-

Validity criteria fulfilled:

yes

Remarks:

< 10% immobilisation was observed in the control (0%) and dissolved oxygen was >3 mg/l throughout the test (7.9 - 8.4 mg O2/l)

Conclusions:

A 48-hour EC50 value of >100 mg/l was reported for the effects of the 3-(trimethoxysilyl)propyl acrylate on the mobility of Daphnia magna in a limit test, based on nominal concentrations.

Description of key information

48-hour: EC₅₀ >100 mg/l based on the mobility of Daphnia magna, based on nominal concentrations. The EC₅₀ is equivalent to >82 mg/l when expressed in terms of concentration of the silanol hydrolysis product, 3-acryloxypropylsilanetriol.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

> 82 mg/L

Additional information

A 48-hour EC₅₀ value of >100 mg/l based on the mobility of Daphnia magna was determined in a reliable, limit test conducted under static conditions with the registration substance, 3-(trimethoxysilyl)propyl acrylate (CAS 4369-14-6, EC 419-560-6), in accordance with OECD Test Guideline 202. A 24-hour EC₅₀ value and 48-hour NOEC value of >100 mg/l and =100 mg/l, respectively, were 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 h, however no parent was detected in test solutions after 48 hours. The results are 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 = >100 mg/l] = >82 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.