N-(3-{1,1,1,5,5,5-hexamethyl-3-[(trimethylsilyl)oxy]trisiloxan-3-yl}propyl)prop-2-enamide

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:

2009-09-02 to 2010-03-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Monitored GLP study, following international guidelines

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

N-(3-{1,1,1,5,5,5-hexamethyl-3-[(trimethylsilyl)oxy]trisiloxan-3-yl}propyl)prop-2-enamide

EC Number:

700-253-3

Cas Number:

115258-10-1

Molecular formula:

C15H37NO4Si4

IUPAC Name:

N-(3-{1,1,1,5,5,5-hexamethyl-3-[(trimethylsilyl)oxy]trisiloxan-3-yl}propyl)prop-2-enamide

Study design

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): supplied by the sewage works of Rossdorf, Germany
- Storage conditions: after inital washing aeration overnight
- Storage length: overnight
- Preparation of inoculum for exposure:dilution to stock concentration in test water
- Pretreatment: 3x wash in tap water, centrifugation and resuspension, finally in test water
- Concentration of sludge: stock suspension: 1.5 g/L (on dry matter base)
- Initial cell/biomass concentration: final concentration in test vessel: 31 mg/L
- Test water: reconstituted by adding analytical grade salt solutions

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

25 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: see block "Any other informations on matgerial and methods, incl. tables"
- Additional substrate: no
- Solubilising agent (type and concentration if used): not applicable
- Test temperature: 22 +-1 °C
- pH: Start of test: 7.6; end of test: 6.6 - 7.5
- Aeration of dilution water: yes (before dilution)
- Suspended solids concentration: final concentration in test vessel: 31 mg/L
- Continuous darkness: yes
- Other:

TEST SYSTEM
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: no data
- Method used to create anaerobic conditions: not applicable
- Measuring equipment: BSB Sensomat system, Aqualytic Dortmund
- Test performed in closed vessels due to significant volatility of test substance: no
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used: Potassium hydroxide solution (45%)

SAMPLING
- Sampling frequency: daily
- Sampling method: not applicable
- Sterility check if applicable: not applicable
- Sample storage before analysis: not applicable

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2 x
- Abiotic sterile control: no
- Toxicity control:1 x (HgCl2)

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

Over the whole test period 0% consumtion/degradation could be observed. Results calculated with THOD (NO3) and ThOD (NH4) were identical.

BOD5 / COD results

Results with reference substance:

Results with reference substance bencoic acid, sodium salt and the toxic control with HgCl2 were vaild.

Any other information on results incl. tables

I. Cumulative Biochemical Oxygen Demand (mg O₂/L) in Test Flasks During the Test Period of 28 Days

Time	Flask No.
(days)	1	2	3	4	5	6	7
1	0	0	0	0	55	0	50
2	0	0	0	0	85	0	85
3	0	5	0	5	115	0	110
4	5	5	5	5	120	0	115
5	5	5	5	10	125	0	125
6	5	5	5	10	130	0	130
7	10	10	10	10	135	0	135
8	10	10	10	10	140	0	140
9	10	10	10	10	145	0	145
10	10	10	10	10	145	0	145
11	10	10	10	10	150	0	150
12	10	10	10	10	150	0	150
13	10	10	10	10	155	0	155
14	10	10	10	10	155	0	160
15	15	10	15	15	160	0	165
16	15	15	15	15	165	0	170
17	15	15	15	15	165	0	180
18	15	15	15	15	170	0	190
19	15	15	15	15	175	0	200
20	15	15	15	15	175	0	200
21	15	15	15	15	175	0	200
22	15	15	15	15	180	0	200
23	15	15	15	15	180	0	200
24	15	15	15	15	180	0	200
25	15	15	15	20	180	0	200
26	15	15	15	20	180	0	205
27	15	15	20	20	185	0	205
28	15	15	20	20	185	0	205

where

            Flasks 1 and 2: 2-Propenamide, N-[3-[3,3,3-trimethyl-1,1-bis[(trimethylsilyl)oxy]-1-disiloxanyl]propyl]

            Flasks 3 and 4: inoculum control

Flask 5: reference (procedure control)

            Flask 6: abiotic control

            Flask 7: toxicity control

II. pH Values of the test solutions after the test period (28 d)

Flask No.	Treatment	pH-value
1	2-Propenamide, N-[3-[3,3,3-trimethyl-1,1-bis[(trimethylsilyl)oxy]-1-disiloxanyl]propyl]	7.5
2	2-Propenamide, N-[3-[3,3,3-trimethyl-1,1-bis[(trimethylsilyl)oxy]-1-disiloxanyl]propyl]	7.5
3	Inoculum control	7.5
4	Inoculum control	7.5
5	Procedure control	7.5
6	Abiotic control	6.6
7	Toxicity control	7.5

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The substance 2-Propenamide, N-[3-[3,3,3-trimethyl-1,1-bis[(trimethylsilyl)oxy]-1-disiloxanyl]propyl] is considered not to be readily biodegradable.

Executive summary:

The test item 2-Propenamide, N-[3-[3,3,3-trimethyl-1,1-bis[(trimethylsilyl)oxy]-1-disiloxanyl]propyl] was investigated for its ready biodegradability in a manometric respirometry test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the micro-organisms during exposure. As a reference item sodium benzoate 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 aerobic activated sludge microorganisms after 28 days of incubation.

The test item 2-Propenamide, N-[3-[3,3,3-trimethyl-1,1-bis[(trimethylsilyl)oxy]-1-disiloxanyl]propyl] contains nitrogen, therefore the evaluation of biodegradation has to be based on ThOD_NH4andThOD_NO3. The criterion for ready biodegradability under the conditions of a manometric respirometry test is the 10-day window, describing the period between reaching at least 10% degradation and 60% degradation. This period should not exceed 10 days.

The mean biodegradation after 28 days of 2-Propenamide, N-[3-[3,3,3-trimethyl-1,1-bis[(trimethylsilyl)oxy]-1-disiloxanyl]propyl] was -2% (ThOD_NH4+ThOD_NO3); the 10 day window criterion was not passed.

Therefore, 2-Propenamide, N-[3-[3,3,3-trimethyl-1,1-bis[(trimethylsilyl)oxy]-1-disiloxanyl]propyl] is considered not to be readily biodegradable.