3-(triethoxysilyl)propanethiol

Toxicity to terrestrial arthropods

Administrative data

Endpoint:

toxicity to non-target arthropods on natural substrate (NTA other than pollinators)

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 January 2021 - 22 January 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Principles of method if other than guideline:

In order to avoid the unnecessary use of animals, the threshold approach for fish toxicity testing was employed. In accordance with OECD Guidance document No. 126, the nominal limit test concentration for this study was selected from the lowest EC50 value from the short-term invertebrate and algal tests (see IUCLID sections 6.1.3 and 6.1.5, respectively). Because no toxicity was observed at this concentration (96-hour LC50 > 2.55 mg/l), this indicates that fish are not the most sensitive trophic level and a full OECD TG 203 study is not required.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations:
- Sampling method: Samples were taken at 0 and 72 hours (fresh media) and 24 and 96 hours (24 hour aged media).
- Sample storage conditions before analysis: Samples were frozen in a refrigerator until analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Test item was weighed and transferred into a test vessel with an appropriate amount of the dilution water and adjusted to pH 7 (+/- 0.1). Test media was stirred with a magnetic stirrer at 1100 rpm for 1 hour.
- Controls: dilution water without test item but from the same age and source as the test material solutions
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): None reported

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Strain: Not reported
- Source: gained at test facility from a single brood stock (supplier: Umweltbundesamt, Schichauweg 58, D-12307 Berlin)
- Age at study initiation (mean and range, SD): Juvenile
- Length at study initiation (length definition, mean, range and SD): Initiation values not reported, however average body length at study end was 1.80cm
- Weight at study initiation (mean and range, SD):Initiation values not reported, however average body weight at study end was 0.056g
- Method of breeding: not reported
- Maintenance of the brood fish: holding of stock was performed in accordance with laboratory SOPs Water changed at least once per week, DO was >80% air saturation value

ACCLIMATION
- Acclimation period: 9 days
- Acclimation conditions (same as test or not): Same as test conditions
- Type and amount of food during acclimation: Sera Vipan food. Amount was 4% of fish body weight per feeding day.
- Feeding frequency during acclimation: food provided 3 times per week and given to satiation per feeding day. Test fish were not fed 24h before test start
- Health during acclimation (any mortality observed): no mortality observed


FEEDING DURING TEST - fish not fed during test

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

66 mg/L total hardness

Test temperature:

23.0 - 23.9 degrees C

pH:

7.05 - 7.95

Dissolved oxygen:

84 - 100% oxygen saturation

Salinity:

Not reported

Conductivity:

Not reported

Nominal and measured concentrations:

Nominal: control and 4 mg/L
Measured: control (

Details on test conditions:

TEST SYSTEM
- Test vessel: glass 3L aquaria
- Type (delete if not applicable): open (covered with glass plates)
- Material, size, headspace, fill volume: 2.5 L per vessel
- Aeration: no aeration provided
- Renewal rate of test solution (frequency/flow rate): test media renewed at 72 hours
- No. of organisms per vessel: 7 fish per concentration and 7 for the control
- No. of vessels per concentration (replicates):1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.157 g fish per liter test solution

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: same used as holding - tap water of local origin. Water was filtered on activated charcoal and aerated for at least 24 hours to remove chlorine
- Total organic carbon: <2 mg/L
- Particulate matter: not reported
- Metals: not reported
- Pesticides: not reported
- Chlorine: < 0.01 mg/L
- Alkalinity: not reported
- Ca/mg ratio: not reported
- Culture medium different from test medium: no
- Intervals of water quality measurement: pH, temperature and oxygen saturation were measured in all test vessels daily, chlorine and nitrate were measured from each batch of dilution water used in the test. Hardness was determined at the start of the exposure, TOC was sampled at the start of the exposure and frozen until analysis. Water temperature was continuously recorded.

OTHER TEST CONDITIONS
- Adjustment of pH: New test solutions (0 and 72h renewals) were adjusted to 7.0 +/- 0.1 before and after application of the test item
- Photoperiod: 16h / 8h light dark cycle
- Light intensity: 540 - 1000 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : observations were made after 2+/- 0.5h and 5 +/- 1h after the start of the exposure. On days 1-4 of the test, all vessels with living fish were inspected twice per day. Measurements of fish weight and size were conducted at the end of the exposure. Fish were considered dead if there was no visible movement (e.g. gill covers movement) and if touching of the caudal peduncle produced no reaction. Records were kept of visible abnormalities (e.g. loss of equilibrium, swimming behavior, respiratory function, pigmentation, etc.).

TEST CONCENTRATIONS
- Justification for using less concentrations than requested by guideline: limit test

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

>= 2.55 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 2.55 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities:
- Observations on body length and weight: Average body length at end of test = 1.80 cm, average body weight at end of test = 0.056 g
- Other biological observations: behaviour was monitored but no abnormalities to equilirbium, appearance, swimming behaviour, ventilatory behaviour were observed
- Mortality of control: 0%
- Abnormal responses: No abnormalities to behaviour or fish appearance were observed
- 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:

No effects were observed so statistical analysis was not conducted

Sublethal observations / clinical signs:

Table 1. Observations of sub lethal effects and normal behaviour in the test vessels

Nominal test item concentration (mg/L)	Number of fish affected at observation time (hours)
	Day 0		Day 1		Day 2		Day 3		Day 4
	2	5	22	29	46	53	70	78	94	96
Control	7	7	7	7	7	7	7	7	7	7
4.00	7	7	7	7	7	7	7	7	7	7

Table 2. Measured concentrations of the test item during the definitive test

Sampling date	Fresh media, 0 hours		Old media, 24 hours		Fresh media, 72 hours		Old media, 96 hours
Nominal test item concentration (mg/L)	Measured concentration (mg/L)	%	Measured concentration (mg/L)	%	Measured concentration (mg/L)	%	Measured concentration (mg/L)	%
Control	<LOQ		<LOQ		<LOQ		<LOQ
4.00	3.33	83	1.83	46	3.46	86	2.01	2.55
Geometric mean measured concentration for the test concentration = 2.55 mg/L

Validity criteria fulfilled:

yes

Remarks:

O2 saturation remained above 60% (>=84%), 0% mortality was observed in the control group, analytical measurement of the test concentrations were conducted

Conclusions:

A 96-h LC50 value of >2.55 mg/l and an LC0 of ≥2.55 mg/l have been deternined for the effects of the test substance on mortality of Danio rerio based on geometric mean measured concentrations of the substance. In light of the semi-static test procedure, it is likely that the test organisms were exposed to the parent substance, therefore values have been reported in terms of the parent substance, 3-(triethoxysilyl)propanethiol. The LC50 is equivalent to >1.65 mg/l when expressed in terms of the silanol hydrolysis product, 3-(trihydroxysilyl)propanethiol.

Cross-reference 2

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

7 October 2020 - 9 October 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations:
- Sampling method: All concentration levels and controls were sampled at the start of the exposure and at the renewal of the test solutions (0 and 24 hours), as well as in the 24 hours old media at 24 and 48 hours.
- Sample storage conditions before analysis: samples were stored in a freezer until the start of the analysis if necessary.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: a 10 mg test item/L stock solution was prepared in dilution water, stirred at 1100 rpm for 1 hour at room temperature. The stock solution was added to dilution water to prepare the test concentrations.
- Controls: same as dilution water (Elendt M4 media)
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): none reported
- Other relevant information:

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: not reported
- Age at study initiation (mean and range, SD): <24 hours old
- Weight at study initiation (mean and range, SD): not reported
- Length at study initiation (length definition, mean, range and SD): not reported
- Source: Original stock source: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), 14195 Berlin, Germany. Bred at: Noack Laboratorien GmbH, Käthe-Paulus-Str. 1, 31157 Sarstedt, Germany
- Age of parental stock (mean and range, SD): not reported
- Feeding during test - daphnids were not fed during the study

ACCLIMATION
- Acclimation period: at least 2 hours in dilution water
- Acclimation conditions (same as test or not): same as test
- Health during acclimation (any mortality observed): not reported

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

255 - 265 mg CaCO3/L

Test temperature:

20.3 - 20.7 degrees C

pH:

6.90 - 7.43 in fresh media, 6.64 - 7.29 in 24 hour old media

Dissolved oxygen:

8.73 - 8.96 mg/L in fresh media, 8.00 - 8.60 in 24 hour old media

Salinity:

Not reported

Conductivity:

573 - 659 μS/cm

Nominal and measured concentrations:

Nominal: control, 0.625, 1.25, 2.5, 5.0, 10.0 mg/L
Geometric mean measured concentrations: control, 0.678, 0.960, 1.89, 3.89, 7.67 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers 50mL capacity, loosely covered with watch glasses
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass, 7cm height x 4cm internal diameter
- Volume of solution: 20mL
- Aeration: not reported
- Renewal rate of test solution (frequency/flow rate): test solutions were renewed after 24 hours
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: same as culture medium (Elendt M4 medium)
- Total organic carbon: not reported
- Particulate matter: not reported
- Metals: not reported
- Pesticides: not reported
- Chlorine: not reported
- Alkalinity: not reported
- Ca/mg ratio: not reported
- Conductivity: not reported
- Salinity: not reported
- Culture medium different from test medium: no
- Intervals of water quality measurement: 0 and 24h

OTHER TEST CONDITIONS
- Adjustment of pH: culture medium was adjusted to pH 7.0 +/- 0.1
- Photoperiod: 16/8 hours light/dark cycle
- Light intensity: max 1500 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobilization was determined after 24 and 48 hours. Other adverse, sublethal effects (e.g. behaviur or appearance) was done but none occurred during the study

Reference substance (positive control):

yes

Remarks:

Potassium dichromate tested under static conditions.

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.71 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% C.I. 1.89 - 3.89 mg/L

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

2.03 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% C.I. 1.89 - < 3.89

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

3.89 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

3.79 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% C.I. 1.98 - 7.15

Duration:

24 h

Dose descriptor:

EC10

Effect conc.:

3.52 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 1.88 - 6.97

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

> 7.67 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: behaviour was monitored, but no abnormalities observed
- Other biological observations: appearance was monitored, but no abnormalities observed.
- Mortality of control: 0%
- Immobilisation of control: 0%
- Abnormal responses: observed, but none recorded
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: none
- Effect concentrations exceeding solubility of substance in test medium; not reported

Results with reference substance (positive control):

EC50 = 2.03 mg potassium dichromate/L, which is within the 0.6 - 2.4 mg/l range according to AQS P 9/2 (02/2000)

Reported statistics and error estimates:

EC values were calculated using sigmoidal dose-response regression with GraphPad Prism. 95% confidence intervals were calculated from the standard error and t-distribution.

Table 1. Immobilization rates after 24 and 48 hours of exposure

Geometric mean measured concentration (mg/l)	Immobilization after 24h					Immobilization after 48 hours
	1	2	3	4	Mean	1	2	3	4	Mean
7.67	80	100	100	60	85	100	100	100	100	100
3.89	80	80	60	40	65	100	100	100	100	100
1.89	0	0	0	0	0	0	0	0	0	0
0.960	0	0	0	0	0	0	0	0	0	0
0.678	0	0	0	0	0	0	0	0	0	0
Control	0	0	0	0	0	0	0	0	0	0

Table 2. Absolute numbers of immobile Daphnids after 24 and 48 hours of exposure.

Geometric mean measured concentration (mg/l)	Number of immobile daphnids after 24h					Number of immobile daphnids after 24h
	1	2	3	4	Sum	1	2	3	4	Sum
7.67	4/5	5/5	5/5	3/5	17/20	5/5	5/5	5/5	5/5	20/20
3.89	4/5	4/5	3/5	2/5	13/20	5/5	5/5	5/5	5/5	20/20
1.89	0/5	0/5	0/5	0/5	0/20	0/5	0/5	0/5	0/5	0/20
0.960	0/5	0/5	0/5	0/5	0/20	0/5	0/5	0/5	0/5	0/20
0.678	0/5	0/5	0/5	0/5	0/20	0/5	0/5	0/5	0/5	0/20
Control	0/5	0/5	0/5	0/5	0/20	0/5	0/5	0/5	0/5	0/20

Table 3. Nominal and geometric mean measured concentrations of the test substance throughout the exposure

Nominal test concentration (mg/l)	Fresh media, 0 hours		Old media, 24 hours		Fresh media, 24 hours		Old media, 48 hours		Geometric mean measured concentration (mg/L)
	Measured conc. (mg/l)	% of nominal	Measured conc. (mg/l)	% of nominal	Measured conc. (mg/l)	% of nominal	Measured conc. (mg/l)	% of nominal
10.0	9.75	98	6.24	62	10.3	103	5.51	55	7.67
2.0	5.02	100	2.82	56	5.15	103	3.12	62	3.89
2.5	2.50	100	1.32	53	2.55	102	1.51	60	1.89
1.25	1.20	96	0.742	59	1.25	100	0.763	61	0.960
0.625	0.609	97	0.377	60	1.26	202	0.729	117	0.678
Control	<LOQ		<LOQ		<LOQ		<LOQ		<LOQ

Validity criteria fulfilled:

yes

Remarks:

0% mortality in the controls and >= 8.00 mg O2/L, therefore meeting the OECD 202 validity criteria (<= 10% mortality and >= 3 mg O2/L respectively).

Conclusions:

A 48-h EC50 value of 2.71 mg/l and an EC10 value of 2.03 mg/l have been determined for the effects of the test substance on mobility of Daphnia magna based on geometric mean measured concentrations of the substance. Based on the semi-static test regime, it is likely that the test organisms were exposed to the parent substance, therefore the values have been reported in terms of the parent substance, 3-(triethoxysilyl)propanethiol. The EC50 is equivalent to 1.75 mg/l when expressed in terms of the silanol hydrolysis product, 3-(trihydroxysilyl)propanethiol.

Cross-reference 3

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

5 October 2020 - 8 October 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all test concentrations and the control
- Sampling method: Samples were taken after preparation from one replicate at the start of the exposure. Then, 24 and 48 hour samples were taken from one additional replicate of each test item concentration and the control and analysed immediately. End samples were taken from pooled replicates and analysed immediately.
- Sample storage conditions before analysis: None

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Stock solution of 100 mg/l was prepared with diltuion water, stirred at 1100 rpm for one hour at room temperature. Test solutions were prepared by dilution of the stock solution with test media.
- Controls: same as dilution water (test media)
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): Stock solution was checked via laser beam (Tyndall effect) and no evidence of undissolved test item was found (negative).
- Other relevant information: none reported

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Strain: HINDAK CCAP 278/4
- Source (laboratory, culture collection): origin: Culture Collection of Algae and Protozoa (CCAP), SAMS Research Services Ltd, Dunstaffnage Marine Laboratory, Dunbeg, OBAN; Argyll PA37 1QA; Scotland, UK.
- Age of inoculum (at test initiation): 3 day old preculture
- Method of cultivation: Stocks were cultivated at the test facility using nutrient medium Z, fresh stocks were prepared monthly on Z-Agar.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Hardness:

37 mg CaCO3/l

Test temperature:

22.5 - 23.5 degrees C

pH:

7.11 - 8.29

Dissolved oxygen:

not reported

Salinity:

not reported

Conductivity:

142 μS/cm

Nominal and measured concentrations:

Nominal: control, 1.0, 3.16, 10.0, 31.6, 100 mg/l
Measured: control, 0.319, 0.927, 4.84, 18.7 and 58.6 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: sterile Erlenmeyer flasks, 250mL volume,
- Type (delete if not applicable): sealed with cotton wool plugs
- Material, size, headspace, fill volume: 100ml fill volume
- Aeration: test containers were placed on a rotary shaker and oscillated at approx. 70 rpm
- Initial cells density: 5375 cells/ml
- Control end cells density: 935596 cells/ml
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes - AAP medium (according to OECD guideline)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: ultrapure water (max conductivity was 0.1μS/cm)
- Total organic carbon: - Particulate matter: not reported
- Metals: not reported
- Pesticides: not reported
- Chlorine: not reported
- Alkalinity: 0.6 mmol/l. Acidity: 0.2 mmol/l
- Ca/mg ratio: not reported
- Conductivity: 142 μS/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: at the start of exposure and at the end of the exposure. Room temperature was continuously monitored and light intensity was measured prior to the start of the test.

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: culture media adjusted to pH 7.0 +/- 0.2
- Photoperiod: 24 hours light.
- Light intensity and quality: 4440-8880 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: fluorimeter
- Chlorophyll measurement: The cell density was measured daily via Chlorophyll a fluorescence, excitation at 436 nm, emission at 685 nm. Dilution water was used as a background signal. Self-fluorescence was observed in the preliminary range finding test at the concentration of 100 mg/L
- Other: Microscopic evaluation of the cells at the start and the end of the incubation period was carried out. The cells were checked for unusual cell shapes, colour differences, differences in chloroplast morphology, flocculation, adherence of algae to test containers and agglutination of algae cells.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: √10

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

32.2 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% C.I 27.4 - 40.1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

11.8 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% C.I. 8.64-14.2

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

17.7 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% C.I. 16.1-19.2

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

4.84 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

and yield

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

18.7 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

and yield

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

13.4 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: 95% C.I. 10.3 - 16.4

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

5.05 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: 95% C.I. 3.04 - 8.15

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

7.19 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: 95% C.I. 4.84-10.1

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): Microscopic evaluation of the cells at the start and end of exposure revealed no morphological abnormalities.
- Any stimulation of growth found in any treatment: Yes, minor increase in growth rate in 0.927 and 0.319 mg/l treatments
- 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: no evidence reported

Results with reference substance (positive control):

ErC50 0.903 mg potassium dichromate/l (within the 0.775 +/- 0.558 mg/l range)
EyC50 0.441 mg/l (within the 0.421 +/- 0.339 mg/l range)

Reported statistics and error estimates:

Cell density from fluourescence, growth rate, growth rate inhibition, yield and yield inhibition were calculated according to OECD TG 201.
ECx values were determined by sigmoidal dose-response regression. NOEC and LOEC values were calculated using Dunnett's method with Shapiro-Wilk's normality test and Brown-Forsythe's equal variance tests conducted beforehand.

Table 1. Mean cell densities at daily intervals throughout the exposure period

TWA mean measured concentration (mg/l)	Mean cell density (cells/ml)
	0 hours	24 hours	48 hours	72 hours
58.6	5375	5648	5657	5527
18.7	5375	19670	67880	303162
4.84	5375	25624	152162	849232
0.927	5375	29022	190618	963663
0.319	5375	31079	191744	928897
Control	5375	32894	208323	935596

Table 2. Mean growth rate and yield after 72 hours' exposure

TWA mean measured concentrations (mg/l)	Mean growth rate (d^-1)	Inhibition of growth rate (%)	Yield (cells/ml)	Inhibition of yield (%)
58.6	0.0077	99	152	100
18.7	1.34	22	297787	68
4.84	1.69	2	843857	9
0.927	1.73	-1	958288	-3
0.319	1.71	0	923522	1
Control	1.72	-	930221	-

Table 3. Measured concentrations during the definitive test with algae

Nominal concentration (mg/l)	0 hours		24 hours		48 hours		72 hours		TWA mean measured concentration (mg/l)
	Meas. Conc. (mg/l)	%	Meas. Conc. (mg/l)	%	Meas. Conc. (mg/l)	%	Meas. Conc. (mg/l)	%
100	107	107	69.7	70	48.3	48	33.4	33	58.6
31.6	32.7	104	23.2	73	15.6	49	9.93	31	18.7
10.0	9.84	98	6.63	66	4.82	48	1.28	13	4.84
3.16	2.97	94	2.09	66	1.40	44	0.0292	<1	0.927
1.0	0.955	95	0.633	63	0.332	33	<LOQ	-	0.319
Control	<LOQ		<LOQ		<LOQ		<LOQ		-

LOQ = 0.05 mg/l of the test item

Validity criteria fulfilled:

yes

Remarks:

Control cultures increased by 174 fold (which is > 16 fold specified in the guideline), mean COV for each day in the controls was 11.8% (<35%) and COV of average specific growth rates was 1.41% in the controls (<7%)

Conclusions:

A 72-h ErC50 value of 32.2 mg/l, an ErC10 value of 11.8 mg/l and a NOEC of 4.84 mg/l have been determined for the effects of the test substance on growth rate of Pseudokirchneriella subcapitata, based on time weighted average measured concentrations of the parent substance. The test substance hydrolyses in water and based on the static exposure regime, it is likely that the test organisms were primarily exposed to a mixture of the parent and hydrolysis products of the substance. The ErC50, ErC10 and NOEC values are equivalent to 20.8, 7.6 and 3.1 mg/l when expressed in terms of the silanol hydrolysis product, 3-(trihydroxysilyl)propanethiol.

Cross-reference 4

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1996-02-29 to 1996-03-14

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to an EU method, and in compliance with GLP, however no analytical monitoring was undertaken.

Qualifier:

according to guideline

Guideline:

EU Method C.8 (Toxicity for Earthworms: Artificial Soil Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM

- Common name: Earthworm, Eisenia foetida foetida

- Source: Eisenia GmbH und Co, Wiesbaden, Germany

- Age at test initiation (mean and range, SD): 2 months

- Weight at test initiation (mean and range, SD): 300 - 600 mg

Study type:

laboratory study

Substrate type:

other: quartz sand

Limit test:

yes

Total exposure duration:

14 d

Test temperature:

20 +/-2 ºC

pH:

5.7

Moisture:

40%

Details on test conditions:

TEST SYSTEM

- No. of organisms per container (treatment): 10

- No. of replicates per treatment group: 4

- No. of replicates per control: 4

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)

- Composition (if artificial substrate): Quartz sand

OTHER TEST CONDITIONS

- Photoperiod: Daylight

- Light intensity: ca. 400 Lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality after 7 and 14 days exposure

VEHICLE CONTROL PERFORMED: no

TEST CONCENTRATIONS

- Limit test at 1000 mg/kg

Nominal and measured concentrations:

Nominal: 1000 mg/kg

Reference substance (positive control):

no

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- Mortality at end of exposure period: 0

Reported statistics and error estimates:

No toxic effects on survival and growth were observed in the test and therefore statistical analysis of the results was not required.

Validity criteria fulfilled:

yes

Conclusions:

A reliable 14-day LC50 of >1000 mg/kg dry weight has been reported for the test substance to Eisenia foetida. A NOEC of ≥1000 mg/kg dry weight was also determined in the test.

Materials and methods

Test material

Test material information

Constituent 1

Reference substance name:

3-(triethoxysilyl)propanethiol

EC Number:

238-883-1

EC Name:

3-(triethoxysilyl)propanethiol

Cas Number:

14814-09-6

Molecular formula:

C9H22O3SSi

IUPAC Name:

3-(triethoxysilyl)propane-1-thiol