N-[3-(triethoxysilyl)propyl]ethylenediamine

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1994-09-07 to 1994-10-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.4-A (Determination of the "Ready" Biodegradability - Dissolved Organic Carbon (DOC) Die-Away Test)

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): activated sludge from a primarily communal sewage treatment plant (Marl- East)

- Preparation of inoculum for exposure: washed

- Concentration of sludge: 27.6 g/ml

Duration of test (contact time):

28 d

Initial conc.:

10.7 other: mg/L DOC

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS

- Test temperature: 21.9-22.2°C

- Continuous darkness: yes

TEST SYSTEM

- Culturing apparatus: 2L Erlenmeyer flasks with loose closure of aluminium foil

- Number of culture flasks/concentration: two test substance flasks, two control flasks, two innoculum blank flasks.

SAMPLING

- Sampling frequency: 0 hours, 3 hours, 7, 14, 21, 27, 28 days

- Sampling method: samples were centrifuged at 3000RPM for 15 min, then duplicate determination of oxygen-enriched and de-gassed samples

CONTROL AND BLANK SYSTEM

- Inoculum blank: yes

Reference substance:

benzoic acid, sodium salt

Remarks:

10.8 mg/L DOC

Parameter:

% degradation (DOC removal)

Value:

39

Sampling time:

28 d

Details on results:

Biodegradation of reference substance was 98% after 7 days.

Table 1: Dissolved organic carbon levels (mg/l) and calculated % DOC reduction

Type of suspension	0		3 hours		7		14		21		27		28
	DOC (mg/l)	DOC reduction (%)	DOC (mg/l)	DOC reduction %	DOC (mg/l)	DOC reduction (%)	DOC (mg/l)	DOC reduction (%)	DOC (mg/l)	DOC reduction (%)	DOC (mg/l)	DOC reduction (%)	DOC (mg/l)	DOC reduction (%)
Test sample - median value flask 1	8.49	0	8.27	0	4.77	47.59	4.76	45.81	4.48	48.98	4.71	48.10	5.21	41.75
Test sample - median value flask 2	8.88	0	8.37	0	4.97	45.74	4.54	49.25	4.49	49.50	4.47	51.75	5.74	35.84
Test sample - Mean value		0		0		47		48		49		50		39
Blank mean value	0.51	-	0.39		0.64	-	0.49	-	0.46	-	0.62	-	0.62	-
Reference substance – median value flask 1	11.64	0	11.89	0	0.82	98.43	0.64	98.70	0.51	99.57	0.72	99.13	0.74	98.96
Reference substance – median value flask 2	11.31	0	11.44	0	0.83	98.28	0.51	99.82	0.52	99.46	0.76	98.73	0.82	98.19
Median value		0		0		98		100		100		99		99

Validity criteria fulfilled:

yes

Interpretation of results:

other: not readily biodegradable

Conclusions:

A biodegradation result of 39% in 28 days (DOC) was determined in a reliable study conducted according to an appropriate test protocol, and in compliance with GLP.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Please refer to the attached justification for grouping of substances in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Parameter:

% degradation (DOC removal)

Value:

39

Sampling time:

28 d

Description of key information

Not readily biodegradable (39% in 28 days, EU Method C.4-A) based on read across data from CAS 1760 -24 -3.

Additional information

There are no reliable ready biodegradation data available for N-[3-(triethoxysilyl)propyl]ethylenediamine (CAS 5089-72-5), therefore good quality data for the analogue, N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3), have been read across. Both substances share the same silanol hydrolysis product, N-[3-(trihydroxysilyl)propyl]ethylenediamine, the other hydrolysis products are ethanol and methanol, which were readily biodegradable. Both substances are expected to hydrolyse within the timescale of a ready biodegradation test.

Both N-[3-(triethoxysilyl)propyl]ethylenediamine (CAS 5089-72-5) and N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3) are within a wider analogue group. Substances within this wider analogue group, in general, exhibit no evidence of any significant biodegradation once hydrolysis and subsequent biodegradation of alkoxy/acetoxy groups has been taken into account. It is therefore considered valid to read-across the results for N-(3-(trimethoxysilyl)propyl)ethylenediamine to fill the data gap for the registered substance. The other hydrolysis products for the two substances are ethanol and methanol, which are readily biodegradable (OECD, 2004a and OECD, 2004b).

This wider analogue group for the ready biodegradability endpoint consists of a number of sub-classes of substances. However, read-across is carried out between substances with the same sub-class in most cases.

Table 4.1.4 presents ready biodegradation data available for substances within the sub-class (III-8) of chlorosilanes, siloxanes, silanes and alkoxysilanes etc, with amino functional group(s) in side chain after any very rapid hydrolysis has been accounted for. Both N-[3-(triethoxysilyl)propyl]ethylenediamine (CAS 5089-72-5) and N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3) are members of this sub-class.

The key study (1994) was performed according to EU method C.4 (Determination of the “ready” biodegradability - Dissolved organic carbon (DOC) Die-away-test) and GLP. The biodegradation values calculated from Dissolved Oxygen Depletion performed during the test of 28 days revealed 11.1% at 2 mg/l test concentration. Therefore, the test item was not readily biodegradable under the conditions in the closed bottle test performed. N-(3-(trimethoxysilyl)propyl)ethylenediamine is not readily biodegradable, the observed biodegradation (39% after 28 days) is of the hydrolysis product methanol. The study is considered to be reliability 1 (reliable without restrictions).

Table 4.1.4: Ready biodegradation data available for substances within the relevant sub-class (III-8) of chemicals.

CAS	Name	Readily biodegradable? Yes/no	Result: Biodegradation after 28 day	Guideline	Reliability	Corrected % biodegradation once alkoxy/acetoxy biodegradation is accounted for
027445-54-1	Cyclohexanamine,N-[(diethoxymethylsilyl)methyl]-	No	29% (26% taking into account nitrification)	OECD 301F	1a	-7 (i.e 0)
	[N,N-Bis(trimethylsilyl)aminopropyl]methyldiethoxysilane	No	23% (BOD); 22% (TOC)	OECD 301C	1a	-6 (i.e 0)
000919-30-2	3-aminopropyltriethoxysilane	No	67%	Annex V C4-A	1a	0
031024-56-3	N-[3-(trimethoxysilyl)propyl]butylamine	No	24.7%	OECD 301B	1a	-5 (i.e 0)
227085-51-0	N-ethyl-3-trimethoxysilyl-2-methylpropanamine	No	16 - 18%	OECD 301F	1a	-15 (i.e 0)
157923-74-5	2,2-dimethyl-4-(trimethoxysilyl)butylamine	No	36%	OECD 301F	1a	3
003069-33-8	N-[3-(methoxydimethylsilyl)propyl]ethylenediamine	No	11.1%	OECD 301D	1a	-1 (i.e 0)
001760-24-3	N-(3-(trimethoxysilyl)propyl)ethylenediamine	No	39%	Annex V C4-A	1a	2
None	reaction mix (reaction mass of 6 benzylated amine silanes)	No	29 and 17%	OECD 301B	1a
149048-48-6	1,3-Benzenedimethanamine, reaction products with 3-chloropropyltrimethoxysilane	No	19% (BOD); 20% (TOC)	OECD 301C	1a	-1 (i.e 0)
082985-35-1	Bis(trimethoxysilylpropyl)amine	No	11-20%	OECD 301D	1a	-30 (i.e 0)

References:

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

OECD (2004b): SIDS Initial Assessment Report for SIAM 19, Berlin, Germany, 19-22 October 2004, Ethanol, CAS 64-17-5.