3-aminopropyltriethoxysilane

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1993-06-22 to 1993-06-24

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)

Principles of method if other than guideline:

DIN 38412 Part 1; EG Guideline 92/69/EWG

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

The DOC concentration of the filtered stock solution used to prepare the test media was determined.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

- Method:The test substance was added to dilution water to provide a nominal concentration of 1 g/l and stirred for 18 hours. The solution was filtered and the DOC content determined to be 534 mg/L, which is equivalent to 1093 mg/L of the test substance. This solution served as the primary stock solution of the test substance for preparation of the other test concentrations. The test began immediately after preparation of the test solution.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM

- Common name: Daphnia magna

- Strain: Clone 5

- Source: Stock culture

- Age at study initiation (mean and range, SD): <24 h

- Method of breeding: Parthenogenetic reproduction

- Feeding during test: None

ACCLIMATION

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

- Type and amount of food: Scenedesmussubspicatus, sufficient to be consumed each day leaving no residue

- Feeding frequency: daily

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

Water hardness was reported  as 2.5mmol/L and alkalinity was reported as 0.8 mmol/L.

Test temperature:

20ºC

pH:

The control pH was 7.5 units and the test vessel pH ranged from 7.5 to 8.7 units. 

Dissolved oxygen:

The control DO was 8.4 mg/L and the test vessel DO ranged from 7.8 to 8.7 mg/L.

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal concentrations (based on measured concentrations in stock solution):  0, 8.7, 16.4, 28.4, 54.7, 94.0, 174.9, 306.0, 546.5, and 983.7 mg/L.

Details on test conditions:

TEST SYSTEM

The test vessels were glass cylinders graduated to 10 ml. Each concentration had 4 replicate vessels and each vessel contained 5 test organisms.  The age of the test organisms was <24 hours and they were not fed during the test.  Vessels were kept in the dark at 20ºC and not aerated during the  test.

The dilution water was synthetic fresh water with a hardness of approximately 294 mg/L as CaCO3

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

94 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

331 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 249-441

Details on results:

- Mortality of control: 0

Results with reference substance (positive control):

24 h EC50 lies between 0.9 and 1.9 mg/L

Reported statistics and error estimates:

EC50 values were calculated by Probit analysis. The NOEC was determined by visual examination of the raw data

Table 1. Test results

Nominal test concentration (mg/L)	Mean percentage immobilisation after 24 hours	Mean percentage immobilisation after 48 hours
0 (Control)	0	0
8.7	0	0
16.4	5	5
28.4	0	0
54.7	0	0
94.0	5	10
174.9	19	19
306.0	45	50
546.5	40	60
983.7	62	100

Validity criteria fulfilled:

yes

Conclusions:

A 48-hour EC50 value of 331 mg/L and NOEC of 94 mg/L have been determined for the effects of the test substance on mobility of Daphnia magna. It is likely that the test organisms were exposed to the hydrolysis products of the substance.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2002-08-26 to 2002-12-19

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: 0 (Control) and 100 mg/l

- Sampling method: Duplicate samples of test media were taken at the start and end of the test.

- Sample storage conditions before analysis: samples were analysed immediately after collection.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: A single nominal test concentration of 100 mg/l was prepared by adding 50 mg of test substance to 500 ml of dilution water and stirring intensely for 24 hours.

- Controls: Dilution water

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM

- Strain: Clone 5

- Source: Laboratory culture derived from animals originally obtained in 1997 from the Umweltbundesamt, Institut für Wasser-Boden- und Lufthygie
ne, Berlin, Germany.

- Age at study initiation (mean and range, SD): 7.5-24 hours

- Feeding during test: none

ACCLIMATION

- Acclimation conditions: same as test

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

250 mg/l as CaCO3

Test temperature:

21ºC

pH:

7.8-7.9

Dissolved oxygen:

=8.0 mg/l

Salinity:

not applicable

Nominal and measured concentrations:

Nominal concentrations: 0(Control) and 100 mg/l.

Measured concentrations were between 94 and 95% of nominal at the start of the test and between 87 and 88% at the end of the test. The mean measured concentration was 91 mg/l.

The test results are reported and interpreted with reference to nominal concentration.

Details on test conditions:

TEST SYSTEM

- Test vessel: beaker

- Type: open

- Material, size, headspace, fill volume: glass, 250 ml containing 150 ml of test medium

- Aeration: none

- No. of organisms per vessel: 10

- No. of vessels per concentration (replicates): 2

- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: Reconstituted freshwater prepared by adding analytical grade salts to deionised water.

- Alkalinity: 0.8 mmol/l

- Ca/mg ratio: 4:1

- Culture medium different from test medium: no

- Intervals of water quality measurement: start and end of test

OTHER TEST CONDITIONS

- Adjustment of pH: no

- Photoperiod: 16 h light, 8 h dark

- Light intensity: 460 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): mobility after 24 and 48 hours

TEST CONCENTRATIONS

- Range finding study; yes

- Test concentrations: 100 mg/l

- Results used to determine the conditions for the definitive study: no effects

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

but exposure is to hydrolysis products

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

but exposure is to hydrolysis products

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: none

- Mortality of control: 0

Results with reference substance (positive control):

no data

Reported statistics and error estimates:

There were no toxic effects observed in the test and therefore no statistical tests were required.

No toxic effects were observed following 48 hours exposure to a nominal concentration of 100 mg/l.

Validity criteria fulfilled:

yes

Conclusions:

A 48-hour EC50 value of >100 mg/l and NOEC of =100 mg/l have been determined for the effects of the test substance on mobility of Daphnia magna based on nominal concentrations. The test substance is susceptible to hydrolysis and it is likely that the test organisms were primarily exposed to the hydrolysis products of the substance.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2005-05-23 to 2005-05-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: ISO 14669 - 1999: water quality - Determination of acute lethal toxicity to marine copepods (Copepoda, Crustaceae)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Test solutions were prepared individually by stirring appropriate amounts of the test substance in app. 500 ml of seawater. the solutions were stirred with a spin-bar for 20 hours at a speed which formed a vortex two-thirds of the depth of the fluid content, followed by standstill for 4 hours. Samples for testing were taken from the mid of the water phase with a peristaltic pump.

Test organisms (species):

other: Acartia tonsa, marine copepod

Details on test organisms:

Acartia tonsa was bought as eggs from Marin Biologisk laboratorium, Kobenhavn University Helsingor. The test organisms used in the test´ were hatched at M-lab and held at a temperature of 19.8 - 21.8 °C. The test organisms were fed with a culture of Rhodomonas baltica from day 2. At start the test organisms were 14 days (after hatching)

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

no

Hardness:

no data

Test temperature:

20.8 - 21.3°C

pH:

inital values 8.4 at lowest nominal concentration of 31.9 mg/l to 9.8 at highest nominal concentration of 3199 mg/l

Dissolved oxygen:

initial values 7.1 mg/l - 7.2 mg/l

Salinity:

the used natural seawater has a salinity of 34.5%

Nominal and measured concentrations:

nominal concentrations: 31.9; 98.1; 336; 1015 and 3199 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: glass containers (28 ml rolled rim vials) each containing 25 ml of test solution
- Type (delete if not applicable): open
- No. of organisms per vessel: five
- No. of vessels per concentration (replicates): four
- No. of vessels per control (replicates): six

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Natural seawater from unpolluted site was collected from a tap, after filtration through sand filter. The seawater was filtered through a GF/C filter, and briefly heated to about 75°C prior to use

OTHER TEST CONDITIONS
- Photoperiod: 16h/8h light/dark period

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Lethality (number of dead organisms) was registered after 24 and 48 h by visual observation.

- Test concentrations: 31.9; 98.1; 336; 1015 and 3199 mg/l

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol 97%, CAS: 591-35-5

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

1 200 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95%CL

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

336 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95%CL

Duration:

48 h

Dose descriptor:

LC10

Effect conc.:

380 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95%CL

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

580 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95%CL

Duration:

48 h

Dose descriptor:

other: LC90

Effect conc.:

900 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95%CL

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

336 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95%CL

Results with reference substance (positive control):

- Results with reference substance valid? yes,
- Mortality: 28%
The LC50 result of the 48h test with 1.0 mg/l 3.5-dichlorophenol should be within 20-80%.

Reported statistics and error estimates:

The 48 h LC50 value and the 95% CL were calculated by using the standard procedure PROBIT Analyis, National Swedish Environment Protection Board (Version 2.3, 1990). This programme also calculated test concentrations lethal to 10% and 90% of the test organisms. Due to the fact that insufficient data were available for statistical evaluation, the 24 h LL50 value were calculated by interpolation.
Calculation of NOEC is done by single-factor ANOVA followed by Dunnets procedure for comparing each concentration mean with the control mean.

Response (mortality) of the copepod during the test with Dynasylan AMEO 

Concentration (mg/l)	Total Number     Specimen p. conc.	Number of Specimen pr. Vessel A     B     C D     E      F	NUMBER of DEAD                 24 hours                                 48 hours A   B  C                               A   B   C         D   E   F           Total            D   E   F          Total
Control	30	5      5      5 5      5      5	0    0   0                               0    0    0 0    0   0               0              0    0    0             0
31.9	21	5      5      5 6	0    0   0                               0    0   0 0                            0             1                           1
98.1	20	5      5       5 5	0    0   0                               0    0   0 0                            0             0                           0
336	20	5      5      5 5	0    0   0                               0    1   0 0                             0             0                           1
1015	20	5      5      5 5	1    3   2                               5    5   4 2                            8             5                          19
3199	20	5      5      5 5	5    5   5                               5    5    5             5                           20                                         20
Reference 1.0mg/l	32	5      5      5 6      5      6	0    1   0                                2    2    1 0    0   0               1             1    1    2             9

 

Validity criteria fulfilled:

yes

Conclusions:

The 48 hour LC50 of 580 mg/l and the NOEC of 336 mg/l have been determined for the effect of the test substance on mortality of marine copepod Acartia tonsa. It is likely that the test organisms were exposed predominantly to the hydrolysis products of the test substance.

Description of key information

48 hour EC₅₀: Freshwater: 331 mg/l, mobility of Daphnia magna; equivalent to 205 mg/l as 3-aminopropylsilanetriol, read across from 3-aminopropyl(triethoxy)silane (CAS 919-30-2).

48 hour LC₅₀: Marine water: 580 mg/l, mortality of Arcatia tonsa; equivalent to 359 mg/l as 3-aminopropylsilanetriol, read across from 3-aminopropyl(triethoxy)silane (CAS 919-30-2).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

205 mg/L

Marine water invertebrates

Marine water invertebrates

Dose descriptor:

EC50

Effect concentration:

359 mg/L

Additional information

A 48-hour EC₅₀ value of 331 mg/L (nominal concentration) has been determined for the effects of 3-aminopropyl(triethoxy)silane (CAS 919-30-2) on mobility of the freshwater invertebrate Daphnia magna, in accordance with Test Guideline OECD 202 and in compliance with GLP (Hüls, 1993).

The test substance is susceptible to hydrolysis and, due to the test media preparation (stirring for 18 hours) and exposure regime (static), it is likely that the test organisms were predominantly exposed to the hydrolysis products of the substance.

The results may be expressed in terms of concentration of the hydrolysis product, 3-aminopropylsilanetriol, by applying a molecular weight correction: (MW of silanol = 137.21 / MW of parent = 221.37) * 331 mg/L = 205 mg/L.  

The registration substance is susceptible to hydrolysis reaction of the alkoxysilane groups (to silanols) and to potential condensation reactions (described in Section 4.8 of IUCLID and Section 1.4 of the CSR). Pre-hydrolysis and filtration were used as part of media preparation. Analytical recoveries by DOC were high (within 20% of nominal). Models would suggest that the irreversible condensation is unlikely for these silanol hydrolysis products at the concentrations relevant to the studies (PFA, 2016am).

In a separate test, a 48-hour LC₅₀ value of 580 mg/l (nominal concentration) has also been determined for the effects of 3-aminopropyl(triethoxy)silane (CAS 919-30-2) on mortality of the marine copepod Acartia tonsa, in accordance with test guideline ISO 14669 - 1999: water quality - Determination of acute lethal toxicity to marine copepods (Copepoda, Crustaceae) (Test Institute, 2005). It is likely that the test organisms were exposed to the hydrolysis products of the substance.

The results may be expressed in terms of concentration of the hydrolysis product, 3-aminopropylsilanetriol, by applying a molecular weight correction: (MW of silanol = 137.21 / MW of parent = 221.37) * LC₅₀ 580 mg/L = 359 mg/L.

 

These findings are supported by a 48-hour EC₅₀ in Daphnia magna >100 mg/l, determined for 3-(trimethoxysilyl)propyl isocyanate (CAS 15396-00-6) (IBACON, 2003). For this substance the isocyanate group is very rapidly hydrolysed to the corresponding amine (half-life <1 minute at pH 7), and further hydrolysis of the alkoxy groups proceeds at a slower rate (half-life of 2.8 h at pH 7 and 20-25 °C, estimated) to 3-aminopropylsilanetriol and methanol.