Reaction mass of 2-{[3-(trimethoxysilyl)propyl]amino}ethanaminium chloride and 2-{benzyl[3-(trimethoxysilyl)propyl]amino}ethanaminium chloride and N-[2-(benzylamino)ethyl]-3-(trimethoxysilyl)propan-1-aminium chloride and N-[2-(dibenzylamino)ethyl]-3-(trimethoxysilyl)propan-1-aminium chloride and N-benzyl-2-{benzyl[3-(trimethoxysilyl)propyl]amino}ethanaminium chloride and N-benzyl-N-[2-(dibenzylamino)ethyl]-3-(trimethoxysilyl)propan-1-aminium chloride.

Bioaccumulation: aquatic / sediment

Administrative data

Endpoint:

bioaccumulation in aquatic species: fish

Data waiving:

other justification

Justification for data waiving:

other:

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: EU Method C.10 ("Abiotic degradation: Hydrolysis as a function of pH")

GLP compliance:

yes

Radiolabelling:

no

Analytical monitoring:

no

Estimation method (if used):

Chemical analysis using Gas Chromatographic analytical method to determine the concentration of organifucntional silane A-1128 in the solution. The test substance is dissolved in methanol. The concentration of the test substance is determined before and after addition of water.

Details on test conditions:

TEST MEDIUM
- Volume used/treatment: no
- Preparation of test medium: A standard solution of the resulting residue was perpared in methanol (LiChrosolv, Merck, Darmstadt, FRG) at the concentration 1.9 g/L. This stock solution was diluted 10 times with methanol. Also dilutions were perpared with addition of 0.2, 1.0, 5.0 and 10.0% Milli-Q water (Millipore Corp.)
- If no traps were used, is the test system closed: After evaporation step the test substance-containing container was flushed with nitrogen and closed.
OTHER TEST CONDITIONS
- Temperature: The test was performed at ambient temperature and remained below 30 °C during the evaporation procedure

Duration:

16.8 min

Initial conc. measured:

190 mg/L

Number of replicates:

5

Preliminary study:

For results see field `any other information on results incl. tables´

Transformation products:

not measured

Hydrolysis rate constant:

< 16 min-1

Table 1: Results of the preliminary test.
Concentration test substance (mg/l)^0after addition of % water.
0%	0.2%	1.0%	5.0%	10.0%
190^1(100%)^2	188 (99%)	131 (69%)	53 (28%)	0 (0%)
^0Mean value of duplicate analysis, quantification was performed with the peak with tr16.8 min. ^1Weighed amount. ^2Percentage between brackets is relative concentration.

Conclusions:

Hence it was concluded that organofunctional silane A-1128 is extremely hydrolytically unstable.

Cross-reference 2

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

partition coefficient

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Principles of method if other than guideline:

The result was obtained using an appropriate QSAR method (see attached QMRF and QPRF for details).

GLP compliance:

no

Partition coefficient type:

octanol-water

Key result

Remarks on result:

other: Multi-constituent substance: the partition coefficients of the hydrolysis products of the individual components will be different.

Multi-constituent substance: the partition coefficients of the individual components will be different.

The predictions are based on the unprotonated molecular form of the hydrolysis products.

                                               

The partition coefficient value for the individual components is given in the table below.

 

Name of component	Log Kow
2-{[3-(trihydroxysilyl)propyl]amino}ethanaminium chloride	-3.4
2-{benzyl[3-(trihydroxysilyl)propyl]amino}ethanaminium chloride	-1.4
N-[2-(benzylamino)ethyl]-3-(trihydroxysilyl)propan-1-aminium chloride	-1.2
N-[2-(dibenzylamino)ethyl]-3-(trihydroxysilyl)propan-1-aminium chloride	0.7
N-benzyl-2-{benzyl[3-(trihydroxysilyl)propyl]amino}ethanaminium chloride	0.7
N-benzyl-N-[2-(dibenzylamino)ethyl]-3-(trihydroxysilyl)propan-1-aminium chloride	2.6

 

Conclusions:

Log Kow values for the hydrolysis products (molecular un-protonated form) were determined using an appropriate calculation method which is considered to be reliable:
2-{[3-(trihydroxysilyl)propyl]amino}ethanaminium chloride -3.4
2-{benzyl[3-(trihydroxysilyl)propyl]amino}ethanaminium chloride -1.4
N-[2-(benzylamino)ethyl]-3-(trihydroxysilyl)propan-1-aminium chloride -1.2
N-[2-(dibenzylamino)ethyl]-3-(trihydroxysilyl)propan-1-aminium chloride 0.7
N-benzyl-2-{benzyl[3-(trihydroxysilyl)propyl]amino}ethanaminium chloride 0.7
N-benzyl-N-[2-(dibenzylamino)ethyl]-3-(trihydroxysilyl)propan-1-aminium chloride 2.6

Cross-reference 3

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

No studies are available. Based on molecular structure, molecular weight, water solubility, and octanol-water partition coefficient it can be expected that the registered reaction mass is likely to be absorbed via the oral and dermal routes, but not via inhalation. Hydrolysis occurs rapidly, and exposure is expected to both the parent substances of the reaction mass and the hydrolysis products. Based on the water solubility, the registered reaction mass and its silanol-containig hydrolysis products are likely to be distributed in the body, and excretion via the renal pathway can be expected. The bioaccumulation potential is expected to be low.

Bioaccumulation potential:

low bioaccumulation potential

There are no studies available in which the toxicokinetic properties of the reaction mass containing six benzylated amine silanes have been investigated. Therefore, the toxicokinetic behaviour assessment of the substance and its hydrolysis products was estimated by its physico-chemical properties and the available toxicology studies on the substance itself.  

The test substance hydrolyses rapidly in contact with water (half-life less than 16 min), generating methanol and the remaining benzylated amine silantriols. This suggests that systemic exposure to both the parent and to the hydrolysis products is possible. Hence, this toxicokinetic behaviour assessment will try to predict the behaviour of these substances. The toxicokinetics of methanol is discussed elsewhere and is not included in this summary.

 

The molecular weight range of the reaction mass containing six benzylated amine silanes is 258.8 - 529.2 g/mol. In contrast, the molecular weight range of the hydrolysis products is 212.8 - 483.2 g/mol. The hydrolysis products are smaller in size and are more water soluble and, thereby suggests that it will have greater potential to be absorbed through biological membranes than the parent substance. Furthermore, the moderate range of log Kow of for the parent substance and hydrolysis/condensation products indicate that these substances are lipophilic enough to efficiently pass through biological membranes by passive diffusion.

 

Absorption

Oral: In an acute and a repeated-dose oral toxicity study with the registered reaction mass no signs of systemic toxicity were observed, thus no prediction of systemic availability is possible. If ingestion occurs, the hydrolysis of the parent substance in the low pH of the stomach will be rapid, so any absorption of the parent substance is expected to be minimal and it is more likely to be the hydrolysis product that is absorbed.

The moderate range of log Kow of -0.3-4.2 for the parent substance and hydrolysis/condensation products indicate that these substances are lipophilic enough to efficiently pass through biological membranes by passive diffusion.

 

Inhalation: The vapour pressure of the liquid parent substance (20-26 Pa) and the boiling point (>270 °C) indicates that inhalation of the registered substance as a vapour is unlikely. 

 

Dermal: The moderate log Kow (-0.3-4.2) and molecular weight (258.8 - 529.2 g/mol) of the parent substance suggest that absorption via the dermal route is possible. Slight induction of erythema by the test substance after dermal exposure could enhance dermal absorption.

  

Metabolism:

The registered reaction mass hydrolyses rapidly in contact with water (half-life <16 min), generating methanol and the remaining benzylated amine silantriols. There are no data regarding the enzymatic metabolism of the parent compounds.

 

Excretion:

The low molecular weight and moderate water solubility of the parent and hydrolysis products suggest that they are likely to be excreted by the kidneys into urine.

Materials and methods

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of 2-{[3-(trimethoxysilyl)propyl]amino}ethanaminium chloride and 2-{benzyl[3-(trimethoxysilyl)propyl]amino}ethanaminium chloride and N-[2-(benzylamino)ethyl]-3-(trimethoxysilyl)propan-1-aminium chloride and N-[2-(dibenzylamino)ethyl]-3-(trimethoxysilyl)propan-1-aminium chloride and N-benzyl-2-{benzyl[3-(trimethoxysilyl)propyl]amino}ethanaminium chloride and N-benzyl-N-[2-(dibenzylamino)ethyl]-3-(trimethoxysilyl)propan-1-aminium chloride.

Molecular formula:

Not applicable

IUPAC Name:

Reaction mass of 2-{[3-(trimethoxysilyl)propyl]amino}ethanaminium chloride and 2-{benzyl[3-(trimethoxysilyl)propyl]amino}ethanaminium chloride and N-[2-(benzylamino)ethyl]-3-(trimethoxysilyl)propan-1-aminium chloride and N-[2-(dibenzylamino)ethyl]-3-(trimethoxysilyl)propan-1-aminium chloride and N-benzyl-2-{benzyl[3-(trimethoxysilyl)propyl]amino}ethanaminium chloride and N-benzyl-N-[2-(dibenzylamino)ethyl]-3-(trimethoxysilyl)propan-1-aminium chloride.