Chloromethyltrimethylsilane

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD Guideline Study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Chloromethyltrimethylsilane

EC Number:

219-058-5

EC Name:

Chloromethyltrimethylsilane

Cas Number:

2344-80-1

Molecular formula:

C4H11ClSi

IUPAC Name:

(chloromethyl)trimethylsilane

Test material form:

other: colourless liquid

Details on test material:

Purity 99.8%

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Activated sludge (micro organisms from a domestic waste
water treatment plant) was supplied by sewage plant Rossdorf,
Germany.
The activated sludge used for this study was washed by centrifugation
and the supematant liquid phase was decanted. The
solid material was re-suspended in tap water and again centrifuged.
This procedure was repeated twice.
An aliquot of the final sludge suspension was weighed, dried
and the ratio of wet sludge to its dry weight was determined.
Based on this ratio, calculated aliquots of washed sludge suspension,
corresponding to 4 g dry material per litre were
mixed with test water (see 6.5) and then aerated until use. Before
use the sludge was filtered through cotton wool.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

ca. 5.22 mg/L

Based on:

ThOD/L

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Surrounding Type: Controlled environment room
Temperature: 21.1 - 21.8 °C
Light Conditions: Darkness
pH-Value of Test Water: 7.6 (measured at the start of the test)
Oxygen Concentration of Test Water: 8.8 - 9.0 mg OiL (measured at the start of the test)

Reference substance

Reference substance:

benzoic acid, sodium salt

Remarks:

Sodium benzoate 5.96 /!L/L corresponding to 5.24 mg/L corresponding to a theoretical oxygen demand of 10.25 mg/L (based on ThOD of 1.956 mg oxygen per mg test item)

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

ca. 6

Sampling time:

28 d

Details on results:

Under the test conditions the percentage biodegradation of
Silane CMM3 reached 6% (mean value) after 28 days of
incubation.

BOD5 / COD results

Results with reference substance:

The reference item sodium benzoate as sufficiently degraded
to a mean of 61% after 2 days, and to a mean of
77% after 28 days of incubation, thus confirming the suitability
of the used activated sludge inoculum.
The percentage biodegradation of the reference item confirms
the suitability of the used activated sludge inoculum.

Any other information on results incl. tables

In the toxicity control containing both, the test item and the reference item sodium benzoate, a mean of 42% biodegradation was noted within 14 days and 39% biodegradation after 28 days of incubation.

According to the test guidelines the test item can be assumed not to be inhibitory on the activated sludge micro organisms because degradation was> 25 % within 14 days.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: not readily biodegradable

Conclusions:

Under the test conditions the percentage biodegradation of Silane CMM3
reached 6 % (mean value) after 28 days of incubation.
The test item can therefore be considered not to be readily biodegradable.

Executive summary:

The test item Silane CMM3 was investigated for its ready biodegradability in a Closed Bottle Test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the micro organisms during exposure. A reference item was tested simultaneously under the same conditions as the test item, and functioned as a procedure control. Degradation rate of test item calculated by the oxygen consumption of the activated sludge microorganisms after 28 days of incubation.

Under the test conditions the percentage biodegradation of Silane CMM3 reached 6 % (mean value) after 28 days of incubation. The test item can therefore be considered not to be readily biodegradable.

The reference item sodium benzoate was sufficiently degraded to a mean of 61 % after 2 days, and to a mean of 77 % after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum. In the toxicity control containing both, the test item and the reference item sodium benzoate, a mean of 42 % biodegradation was noted within 14 days and 39 % biodegradation after 28 days of incubation. Thus, the test item can be assumed to be not inhibitory on the activated sludge micro orgamsms. page