Bis(trimethoxysilylpropyl)amine

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:

disregarded due to major methodological deficiencies

Study period:

1988-08-09 to 1988-08-11

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: non reliable study

Remarks:

study not in accordance with current OECD 202 standards (e.g. number of animals per replicate too high, insufficient information on test substance purity)

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: A stock solution of the substance was prepared in 1% Tween 80-acetone. Nine test concentrations plus 1 control and 1 solvent control (including 100 µL/L auxiliary solvent) were then prepared by addition of the stock solution to dilution water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISMS

Source: Laboratory culture originating from a strain supplied by IRCHA, France.

Culture conditions: At 20+/-2°C in glass vessels containing two litres of dechlorinated and aged tap-water. Cultures were fed daily with a mixture of fry fish food (Liquifry®) and a suspension of mixed algae (predominantly Chlorella spp.). Culture conditions ensure that reproduction is by parthenogenesis.

Test organisms: Gravid adults were isolated 24 hours prior to initiation of the test. Young daphnids produced overnight by these adults were used for testing.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

Approximately 350 mg/L as CaCO3

Test temperature:

22°C

pH:

7.9-8.0

Dissolved oxygen:

7.9-8.3 mg/L

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal concentrations: 0 (Control), 0 (Solvent control), 0.10, 0.18, 0.32, 0.56, 1.0, 1.8, 3.2, 5.6 and 10 mg/L.

Details on test conditions:

- Test vessels: Glass jars each containing 200 mL test solution.

- Experimental design: Nine test concentrations plus 1 control and 1 solvent control (including 100 µL/L auxiliary solvent), each in duplicate. 20 animals per test concentration.

- Method of initiation: Daphnia were placed in the test solutions after addition of the test substance.

- Loading: 20 mL test solution per organism.

- Photoperiod: 16 h light : 8 h dark.

- Temperature: 21+/-1°C

- Aeration: None

- Test concentrations: 0 (Control), 0 (Solvent control), 0.10, 0.18, 0.32, 0.56, 1.0, 1.8, 3.2, 5.6 and 10 mg/L.

- Medium renewal: None

- Duration of exposure: 48 hours

- Criteria of effect: Daphnia were considered to be immobilised if they were unable to swim for approximately 15 seconds after gentle agitation.

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

3.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

but exposure is to hydrolysis products

Basis for effect:

mobility

Remarks on result:

other: 2.9-4.1

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

1.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

but exposure is to hydrolysis products

Basis for effect:

mobility

Details on results:

- Immobilisation of control: None

Reported statistics and error estimates:

Analysis of the immobilisation data to determine LC50 values was by the method of Thompson, W.R. & Weil, C.S. (1952), Biometrics 8, 51-54.

Table 1. Test results

 

Nominal concentration (mg/L)	Mean percentage immobilisation after 24 hours	Mean percentage immobilisation after 48 hours
0 (Control)	0	0
0 (Solvent control)	0	0
0.10	0	0
0.18	0	0
0.32	0	0
0.56	0	0
1.0	0	5
1.8	0	10
3.2	5	25
5.6	60	95
10	100	100

Validity criteria fulfilled:

yes

Conclusions:

A 48-hour EC50 value of 3.5 mg/L and a NOEC of 1.8 mg/L have been determined for the effects of the test substance on mobility of Daphnia magna. The test substance hydrolyses rapidly in water and it is therefore likely that the test organisms were primarily 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:

key study

Study period:

05 - 07 Aug 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Daphnia sp., Acute Immobilization Test stipulated in the Testing Methods for New Chemical Substances of Japan

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

Qualifier:

according to guideline

Guideline:

other: OECD Guidance Document, No.23, September 2000, Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: silanol form was measured in all test levels at the start and the end of the exposure. Methanol was measured for the 100 mg/L level (with pH adjustment) and methanol control at the start of the exposure. As the test item hydrolyzes in water and forms silanol and methanol, these both components were measured in the test solutions instead of the test item itself.

- Sampling method: 10 mL of the test solution was taken out from the middle layer of the test vessel.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: test item and dilution water were mixed and stirred for 2 h at approx. 20 °C. The suspension was filtered with a glass fiber filter. Filtrate was sitted for 30 min at approx. 20 °C to recover dissolved oxygen concentration. Test solutions were prepared by diluting this stock solution with dilution water (pH unadjusted). Additional test solutions were prepared in the same way with a final adjustment of the pH to the pH of the dilution water.

- Controls: dilution water processing similar to stock solution without the test item

- Methanol controls: prepared at the concentration corresponding to the theoretical methanol concentration contained in 100 mg/L test solution (theoretical mehtanol concentration = concentration of silanol form * 32.04 (methanol molecular weight) * 6/257.40 (silanol form molecular weight))

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM

- Common name: water flea

- Clone: A

- Source: young Daphnids produced by parents that were cultured in the laboratory were used (initial source: University of Sheffield, United Kingdom)

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

- Feeding during test: no

ACCLIMATION

- Acclimation conditions (same as test or not): same type of water, 20 ± 1 °C, same photoperiod as test

- Type and amount of food: Chlorella vulgaris, 0.1 - 0.2 mg C per day and per Daphnia

- Feeding frequency: once a day

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

30 mg/L as CaCO3

Test temperature:

pH unadjusted: 19.8 - 19.9 °C
pH adjusted: 19.8 - 19.9 °C

pH:

pH unadjusted: 7.7 - 9.2
pH adjusted: 7.8 - 8.0

Dissolved oxygen:

pH unadjusted: 8.8 - 9.0 mg/L
pH adjusted: 8.8 - 9.0 mg/L

Nominal and measured concentrations:

0 (control), 20, 30, 44, 67 and 100 mg/L (nominal, as silanol form, pH unadjusted)
100 mg/L (nominal, as silanol form, pH adjusted)

Details on test conditions:

TEST SYSTEM

- Test vessel: 100 mL glass beaker with a transparent plastic lid

- Fill volume: 100 mL

- Aeration: no

- No. of organisms per vessel: 5

- No. of vessels per concentration (replicates): 4

- No. of vessels per control (replicates): 4

- No. of vessels per methanol control (replicates):4

TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: dechlorinated tap water

- Ca/Mg ratio: 8.5/2.2 mg/L

- Culture medium different from test medium: no

- Intervals of water quality measurement: dissolved oxygen, pH and temperature was measured at the start and at the end of exposure

OTHER TEST CONDITIONS

- Adjustment of pH: highest tested concentration (100 mg/L) was prepared in two parallels, one with and one without pH adjustment

- Photoperiod: 16 h light/8 h dark

- Light intensity: artificial light of white fluorescent lamp

EFFECT PARAMETERS MEASURED: immobility and symptoms of test organisms was recorded at 24 and 48 h of exposure

TEST CONCENTRATIONS

- Spacing factor for test concentrations: 1.5

- Preliminary study: was conducted in order to follow hydrolysis of the the test item. 156 mg/L (as test item concentration) were prepared in ultra pure water. Methanol was measured after 0, 0.5, 1 and 2 hours in order to follow the state of hydrolysis. 94.3, 95.2, 98.5 and 102% of the theoretical formed concentration (87.8 mg/L) was measured after 0, 0.5, 1 and 2 h, respectively.

- Range finding test: yes, static regime, 5 test organisms/test vessel, 2 parallels with and without pH adjustment

- Test concentrations: 100 mg/L

- Results used to determine the conditions for the definitive study: 0 - 20% immobility was observed after 48 h at 100 mg test item/L when no pH adjustment took place (pH: 8.2 - 9.3). 0% mortality was observed after 48 h when pH was adjusted to the pH of the dilution water (pH: 7.7 - 7.9). Based on these results, concentrations between 20 and 100 mg/L were tested at the definitive test. Two parallel tests were run with and without pH adjustment, since the pH exceeded 9 when pH of the medium was not adjusted.

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.

Basis for effect:

mobility

Remarks on result:

other: pH unadjusted

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: pH adjusted

Details on results:

- Mortality of control: no

- Mortality of methanol control: no

Results with reference substance (positive control):

- Results with reference substance valid: yes
- EC50 (48 h): 0.26 mg/L

Validity criteria fulfilled:

yes

Conclusions:

A 48 h EC50 value of > 100 mg/L was determined both when the pH was adjusted or unadjusted. However, NOEC (48 h) was found to be 44 mg/L (nominal) when pH was unadjusted and >= 100 mg/L (nominal) when pH was adjusted to the pH of the dilution water.

Description of key information

EC50 (48 h) >100 mg/L (nominal, OECD 202)

Additional information

Two studies are available evaluating the short term toxicity of bis(trimethoxysilylpropyl)amine (CAS 82985 -35 -1) towards aquatic invertebrates.

The key study was conducted according to the OECD guideline 202 and GLP standards (2014). Daphnia magna was exposed in a static test regime to the nominal test item concentrations of 0 (control), 20, 30, 44, 67 and 100 mg/L with unadjusted pH and to 100 mg/L with pH adjustment. The test item was analytically monitored during the study by LC-MS and GC analysis. Due to rapid hydrolysis of the substance, the hydrolysis products were analytically followed and measured in all test levels at the start and the end of the exposure. The analytical recovery of the hydrolysis products was between 84 - 112% at test start and test end. In both cases (pH adjusted and pH not adjusted) the EC50 (48 h) was > 100 mg/L.

One further study is available conducted according to OECD guideline 202 (1988). However, a vehicle was used in this study and was therefore evaluated as not reliable.