Methyl carbamate

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:

From September 18, 1987 to October 16, 1987

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to OECD Guideline 301D, in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Methyl carbamate

EC Number:

209-939-2

EC Name:

Methyl carbamate

Cas Number:

598-55-0

Molecular formula:

C2H5NO2

IUPAC Name:

methyl carbamate

Test material form:

other: solid

Study design

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Bergen County, New Jersey, MUA

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

3 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: Standard dilution water
- Test temperature: 20±1°C
- Continuous darkness: Yes

TEST SYSTEM
- Culturing apparatus: Flasks
- Number of culture flasks/concentration: 2
- Measuring equipment: YSI Dissolved Oxygen Analyzer 54A

SAMPLING
- Sampling frequency: 0, 5, 15 and 28 d

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes
- Abiotic sterile control: No
- Toxicity control: No

Reference substance

Reference substance:

aniline

Remarks:

2 mg/L

Results and discussion

Test performance:

A 3 mg/L of test substance was inoculated with activated sludge bacteria and kept in closed bottles in the dark in a constant temperature at 20±1°C. A control flask with dilution water and inoculum and another flask with aniline (reference substance) were run in parallel. Dissolved oxygen measurement was done at different intervals i.e. 0, 5, 15 and 28 d.

% Degradation

% Degradation 1

Parameter:

% degradation (O2 consumption)

Value:

15.7

Sampling time:

5 d

% Degradation 2

Parameter:

% degradation (O2 consumption)

Value:

42.5

Sampling time:

15 d

% Degradation 3

Parameter:

% degradation (O2 consumption)

Value:

47

Sampling time:

28 d

Details on results:

Test substance was biodegraded to 47% in 28d.

BOD5 / COD results

Results with reference substance:

Reference substance i.e. aniline was degraded to 95% in 28 d.

Any other information on results incl. tables

Table 1: Dissolved Oxygen Measurements (mg O₂/L)

Medium	Flask	Day
		0	5	15	28
Dilution water without inoculum	C1	8.5	8.4	8.2	8.1
	C2	8.5	8.5	8.3	8.1
	Mean	8.5	8.5	8.3	8.1
Dilution water with inoculum	C3	9.0	8.8	8.2	8.0
	C4	9.0	8.9	7.8	8.2
	Mean	9.0	8.9	8.0	8.1
Test substance (3 mg/L) with inoculum	T1	9.0	7.9	5.8	5.8
	T2	9.0	8.4	6.4	6.2
	Mean	9.0	8.2	6.1	6.0
Reference substance (2 mg/L) with inoculum	R1	9.0	6.1	3.7	2.2
	R2	9.0	6.4	3.3	2.2
	Mean	9.0	6.3	3.5	2.2

 

Table 2: Mean oxygen depletion and percent biodegradation

Medium	Measurement	Day
		5	15	28
Dilution water without inoculum	O2depletion (mg O2/L)	0	0.2	0.4
Dilution water with inoculum	O2depletion (mg O2/L)	0.1	1.0	0.9
Test substance (3 mg/L) with inoculum	O2depletion (mg O2/L)	0.8	2.9	3.0
	TOD	1.49
	%degradation	15.7	42.5	47
Reference substance (2 mg/L) with inoculum	O2depletion (mg O2/L)	2.7	5.5	6.8
	TOD	3.09
	%degradation	42	73	95

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: not readily biodegradable

Conclusions:

The test substance was considered to be not readily biodegradable.

Executive summary:

A study was performed to assess the ready biodegradability of the test substance according to OECD Guideline 301D, in compliance with GLP. 3 mg/L of test substance was inoculated with activated sludge bacteria and kept in closed bottles in the dark in a constant temperature at 20±1°C. A control with dilution water and inoculum, but without test substance was run parallel as a blank correction factor. A test with aniline (reference substance) was also run in parallel. The degradation was followed by oxygen analyses at different intervals i.e. 0, 5, 15 and 28 d. Based on dissolved oxygen measurements, mean oxygen depletion and percent biodegradation was calculated. Since aniline exceeded the pass level by degrading to 95%, this test can be considered valid. To be readily biodegradable, the percent degradation achieved should be 60% or more. However, test substance was biodegraded to 47% after 28d. Under the study conditions, the test substance was considered to be not readily biodegradable (Drozdowski D, 1988).