N-[3-(dimethoxymethylsilyl)propyl]ethylenediamine

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Qualifier:

according to guideline

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

Qualifier:

equivalent or similar to guideline

Guideline:

ISO 10712 (Water quality – Pseudomonas putida growth inhibition test (Pseudomonas cell multiplication inhibition test

GLP compliance:

yes

Analytical monitoring:

no

Details on test solutions:

The test substance was dissolved in double distilled water. Stock solution: 0.625 g / l

Test organisms (species):

Pseudomonas putida

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

16 h

Test temperature:

21.7 - 21.9°C

Nominal and measured concentrations:

Test substance concentrations of 50, 250, 125, 62.5, 31.3, 15.6 mg/l 

Details on test conditions:

Sterile 250-ml Erlenmeyer flasks with ground glass stoppers.
6 growth controls (containing the bacterial suspension)
6 control (test substance and no bacterial suspension)
3 parallel flasks for each of the 6 test concentrations (and bacterial suspension)
1 pH control for each of the 6 test concentrations (and bacterial suspension)

Reference substance (positive control):

no

Key result

Duration:

16 h

Dose descriptor:

EC10

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Key result

Duration:

16 h

Dose descriptor:

EC50

Effect conc.:

67 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Table 1: Controls and test substance: pH, absorption at 432 nm, and percentage inhibition of the growth rate.

Flask	Loading rate (mg/l)	Absorption at 436 nm	% Inhibition growth rate	pH
Test substance (average of three)	500	0.034	99.0	9.4
Test substance (average of three)	250	0.062	97.4	8.4
Test substance (average of three)	125	0.243	87.0	7.6
Test substance (average of three)	62.5	0.998	43.7	7.3
Test substance (average of three)	31.3	1.529	13.3	7.2
Test substance (average of three)	15.6	1.737	1.3	7.1
Control (average of six)	-	1.760	-

 

Conclusions:

A 16hr EC50 value of 67 mg/l and EC10 value of 25 mg/l were determined for toxicity to pseudomonas putida (growth rate) in a reliable study conducted according to an appropriate test protocol, and in compliance with GLP.

Reference 2

Endpoint:

activated sludge respiration inhibition testing

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

See endpoint summary for justification of read-across

Reason / purpose for cross-reference:

read-across source

Duration:

16 h

Dose descriptor:

EC10

Effect conc.:

25 mg/L

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Duration:

16 h

Dose descriptor:

EC50

Effect conc.:

67 mg/L

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Description of key information

Toxicity to microorganisms: 16 hour EC₅₀ of 67 mg/l; EC₁₀ 25 mg/l (Pseudomonas putida, growth rate), read-across from a structurally-related substance, N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3).

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

25 mg/L

Additional information

There are no microorganism toxicity data available for N-[3-(dimethoxymethylsilyl)propyl]ethylenediamine, therefore good quality data for the structurally-related substance N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3), have been read across. Both substances hydrolyse to structurally-related silanol hydrolysis products, N-[3-(dihydroxymethylsilyl)propyl]ethylenediamine and N-(3-(trihydroxysilyl)propyl)ethylenediamine respectively. The other hydrolysis product is methanol.

 

Methanol does not have adverse effects on microorganisms (OECD 2004).

In a respiration inhibition test in a single bacteria strain (Pseudomonas putida) study conducted on N-(3-(trimethoxysilyl)propyl)ethylenediamine, 16 h EC₅₀ of 67 mg/l and EC₁₀ of 25 mg/l were determined. The study was considered to be reliable and conducted in accordance with a relevant test method and in compliance with GLP.

 

N-[3-(Dimethoxymethylsilyl)propyl]ethylenediamine (CAS 3069-29-2) and N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS No. 1760-24-3) are within an analogue group of substances within which in general, there is some evidence of toxicity to microorganisms i.e. an effect concentration (EC) could be derived and was <1000 mg/l.

 

The table below presents microorganism toxicity data available for substances within the analogue group of chlorosilanes, siloxanes, silanes and alkoxysilanes etc. with amino group(s) in the side chain after any very rapid hydrolysis has been accounted for. N-[3-(Dimethoxymethylsilyl)propyl]ethylenediamine (CAS 3069-29-2) and N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3) are members of this analogue group.

It is therefore considered valid to read-across the results for N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3) to fill the data gap for the registered substance. Additional information is given in a supporting report (PFA 2013l) attached in Section 13.

Table 7.4.2 Microorganism toxicity data for relevant substances

CAS	Name	Result: E(I)C50 (mg/l)	Result: NOEC (or EC10/ EC20) (mg/l)	Guideline Number	Test method	Species	Duration (hours)	Reliability
27445-54-1	Cyclohexanamine,N-[(diethoxymethylsilyl)methyl]-	624.2  (EC20 240.2 )		OECD 209	ASRI		3 hours - but stirred 24 hours	1
3068-78-8	N-[3-(Trimethoxysilyl)propylcyclohexylamine]	>1000	EC20 = 203 mg/l	OECD 209	ASRI		3	1
157923-74-5	2,2-Dimethyl-4-(trimethoxysilyl)butylamine	>1000	EC15 869. 17.5% inhibition at 1000 mg/l.	OECD 209	ASRI		3	1
227085-51-0	N-Ethyl-3-trimethoxysilyl-2-methylpropanamine	>1000		OECD 209	ASRI		3	1
919-30-2	3-Aminopropyltriethoxysilane	43	EC10 13 mg/l	Huls AG method	oxygen consumption	P. putida	5.75	2
82985-35-1	Bis(trimethoxysilylpropyl)amine	estimated value, approximately 1000	220	OECD 209	ASRI		3	1
1760-24-3	N-(3-(Trimethoxysilyl)propyl)ethylenediamine	67	EC10 25 mg/l	DIN 38 412, Part 8 (Pseudomonascell multiplication inhibition test)	growth inhibition test	P. putida	16	1
	[N,N-Bis(trimethylsilyl)aminopropyl]methyldiethoxysilane	>100		OECD 209	ASRI		3	1
None	Reaction mix (reaction mass of 6 benzylated amine silanes)	569	130; EC20 172	OECD 209; EC C.11	ASRI		3	1

References:

OECD (2004): SIDS Initial Assessment Report for SIAM 19, Berlin, Germany, 18-20 October 2004, Methanol, CAS 67-56-1.

PFA (2013l). Peter Fisk Associates, STP Microorganism toxicity III-8 Analogue Group report, PFA.300.003.008