2-Propenamide, N-(2,2-dimethoxyethyl)-

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:

2009-10-28 to 2010-01-28

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-(2,2-dimethoxyethyl)prop-2-enamide

EC Number:

610-472-5

Cas Number:

49707-23-5

Molecular formula:

C7 H13 N1 O3

IUPAC Name:

N-(2,2-dimethoxyethyl)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: 7.5; end of test: 6.7 - 7.6
- Aeration of dilution water: yes (before dilution)
- Suspended solids concentration: final concentration in test vessel: 31 mg/L
- Continuous darkness: yes

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: 1
- Toxicity control:1 x (HgCl2)

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

60

Sampling time:

28 d

Details on results:

Over the whole test period 60% 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

1. Cumulative biochemical Oxygen demand over the course of 28 days, raw data, not corrected for Nitrogen

Time	Flask No.
(days)	1	2	3	4	5	6	7
1	0	0	0	0	50	0	45
2	0	0	0	0	75	0	70
3	5	5	5	0	115	0	110
4	5	5	5	5	120	0	120
5	5	5	5	5	130	0	125
6	5	5	5	5	135	0	135
7	10	5	5	5	140	0	140
8	10	10	5	10	145	0	145
9	20	25	10	10	150	0	150
10	35	40	10	10	150	0	155
11	45	50	10	10	155	0	165
12	55	60	10	10	160	0	170
13	75	80	15	15	165	0	180
14	100	95	15	15	170	0	210
15	110	105	15	15	170	0	220
16	115	110	15	15	175	0	225
17	120	115	20	15	180	0	230
18	125	120	20	20	180	0	240
19	130	125	20	20	185	0	245
20	130	125	20	20	185	0	250
21	135	130	25	25	190	0	255
22	135	130	25	25	190	0	255
23	135	135	25	25	190	0	255
24	135	135	25	25	195	0	255
25	140	135	25	25	195	0	260
26	140	140	25	25	195	0	260
27	145	145	25	25	195	0	265
28	150	150	25	25	195	0	265

where:

            Flasks 1 and 2: N-(2,2-Dimethoxyethyl)acrylamide (NAAADA)

            Flasks 3 and 4: inoculum control

Flask 5: reference(procedure control)

            Flask 6: abiotic control

            Flask 7: toxicity control

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable, but failing 10-day window

Conclusions:

The substance is considered to be readily biodegradable under test conditions of the screening test according to OECD 301F.

Executive summary:

The test item N-(2,2-Dimethoxyethyl)acrylamide (NAAADA) contains nitrogen, therefore the evaluation of biodegradation has to be based on the assumption that nitrification occurred, in the following expressed as ThOD_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 of N-(2,2-Dimethoxyethyl)-acrylamide (NAAADA) after 28 days of incubation was 60% (ThOD_NO3); the 10 day window was reached on day 10. If no nitrification is considered, the mean biodegradation was 75% after 28 days of incubation, the 10 day window was also reached on day 10.

The degradation rate of N-(2,2-Dimethoxyethyl)acrylamide (NAAADA) based on ThOD_NO3reached 60% within the 10-day window and after 28 days of incubation. According to the guideline OECD 301, N-(2,2-Dimethoxyethyl)-acrylamide (NAAADA) is considered to be readily biodegradable.

The nitrate concentration in the controls after 28 days of incubation was 10.1 mg/L (mean). The nitrate concentration in the test item treated vessels was 44.7 mg/L (mean). Therefore, the process of nitrification occurred. Therefore, the process of nitrification occurred. After correction of the oxygen demand for the nitrification the biodegradation was 48% after 28 days. In consideration of the fact that the biodegradation was 75%(ThOD_NH4) and 60% (ThOD_NO3) after 28 days, the biodegradation results should be recognized as readily biodegradable, because the nitrification process is a secondary reaction. The process of nitrification was measured but should not be taken into account to evaluate the biodegradation result.