(chloromethyl)triethoxysilane

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:

16 Jul - 26 Sep 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: activated sludge taken from a WTP (Groß-Zimmern, Germany) treating domestic sewage
- Preparation of inoculum for exposure: the sludge was washed
- Initial cell/biomass concentration: 30 mg/L

Duration of test (contact time):

28 d

Initial conc.:

25.1 - 25.5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: reconstituted deionised water
- Test temperature: 21 - 22 °C
- pH: 7.6 - 7.9
- pH adjusted:no
- Continuous darkness: yes


TEST SYSTEM
- Culturing apparatus: Manometric test system
- Number of culture flasks/concentration: 2
- Measuring equipment: BSB/BOD-Sensor system
- Details of trap for CO2 and volatile organics if used: potassium hydroxide (45% aquaeous solution)


CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, 1 replicate
- Abiotic sterile control: yes, 1 replicate
- Toxicity control: yes, 1 replicate

Reference substance:

aniline

Remarks:

Batch No.: K28124761

Parameter:

% degradation (O2 consumption)

Value:

30 - 34

Sampling time:

28 d

Details on results:

Degradation in toxicity control: 70% after 14 days and 68% after 28 days of incubation

Results with reference substance:

Degradation of Anilin: 82% after 14 days and 94% after 28 days of incubation.

Validity criteria fulfilled:

yes

Interpretation of results:

other: not readily biodegradable

Conclusions:

The substance was found not to be readily biodegradable (30-34%, O2 consumption) within 28 d according to OECD criteria.

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 provided in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Parameter:

% degradation (O2 consumption)

Value:

30 - 34

Sampling time:

28 d

Description of key information

Biodegradation in water, screening tests: 30-34 % in 28 days (OECD 301F)

Additional information

There are no reliable ready biodegradation data available for (chloromethyl)triethoxysilane (CAS No. 15267-95-5), therefore good quality data for the structurally-related substance, Silane, (chloromethyl)dimethoxymethyl- (CAS No. 2212-11-5), have been read across. Both substances hydrolyse to structurally-related silanol hydrolysis products, (chloromethyl)silanetriol and (chloromethyl)methylsilanediol, the other hydrolysis products being methanol and ethanol, respectively, which are readily biodegradable (OECD, 2004a and b).

Both chloromethyl)triethoxysilane (CAS No. 15267-95-5) and silane, (chloromethyl)dimethoxymethyl- (CAS No. 2212-11-5) are within a wider analogue group, than the analogue group discussed in Section 1.4. 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.

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.

Table4.1.4presents ready biodegradation data within the analogue group (III-15) of chlorosilanes, siloxanes, silanes and alkoxysilanes etc, with chloroalkyl functional group(s) in side chain after any very rapid hydrolysis has been accounted for.

 Both chloromethyl)triethoxysilane (CAS No. 15267-95-5) and silane,(chloromethyl)dimethoxymethyl- (CAS No. 2212-11-5) are members of this sub-class.

It is therefore considered valid to read-across the results for silane,(chloromethyl)dimethoxymethyl- to fill the data gap for the registered substance. Additional information is given in a supporting report (PFA, 2013f) attached in Section 13 of the IUCLID dossier.

Table 4.1.4: Ready biodegradation data available for substances within the relevant sub-class (III-15) of chemicals.

CAS	Name	Readily biodegradable? Yes/no	Result: Biodegradation after 28 day	Guideline	Reliability	Corrected % biodegradation once alkoxy/acetoxy biodegradation is accounted for
002212-11-5	Silane, (chloromethyl)dimethoxymethyl-	No	30-34%	OECD 301F	1a	-16
007787-93-1	Dichloro(3-chloropropyl)methylsilane	No	0%	EC C4-C	1a	0
013501-76-3	(3-chloropropyl)diethoxymethylsilane	No	56%	EC C4-A	1a	6
002530-87-2	3-chloropropyltrimethoxysilane	No	43%	OECD 301 B	1	-7
005089-70-3	(3-chloropropyl)triethoxysilane	No	46%	EC C4-C	1a	-21
002344-80-1	Chloromethyltrimethylsilane	No	6%	OECD 301D	1a	6

In the study 30–34 % biodegradation was observed in 28 days. The study was conducted according to OECD guideline 301F and is considered reliable (IBACON, 2002). This is selected as the key study.