Ethyl 2-methyl-1,3-dioxolane-2-acetate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27 July 1999 - 24 August 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Inoculum
-Source of sewage effluent: secondary effluent of a domestic sewage treatment plant (Kläranlage Odenthal)
-Treatment given: separation of coarse particles by filtration
-Concentration of effluents in reaction mixture: 5 mL/L
-Preconditioning: aeration for 4 days

Duration of test (contact time):

28 d

Initial conc.:

4 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

The test substance is suspended in a mineral medium, inoculated with a mixed population of aquatic microorganisms and incubated for 28 days under aerobic conditions in the dark at 20 ± 1°C. During this period, the biodegradation of the test substance is determined on the basis of the reduction dissolved oxygen.

Reference substance:

benzoic acid, sodium salt

Remarks:

Purity: 99%; Initail concentration: 2.9 mg/L

Key result

Parameter:

% degradation (O2 consumption)

Value:

3

Sampling time:

28 d

Results with reference substance:

In parallel preparations with the reference substance sodium benzoate a degradation of 73% was achieved within 14 days.

OXYGEN MEASUREMENT

Dissolved oxygen of blank inoculum (mgO₂/L after x days):

Bottle No.	0 days	Bottle No.	7 days	Bottle No.	14 days	Bottle No.	21 days	Bottle No.	28 days
1 2	9.38 9.36	3 4	9.03 9.05	5 6	9.14 9.04	7 8	8.96 9.00	9 10	9.04 9.03
Mean	9.37		9.04		9.09		8.98		9.04

 

Dissolved oxygen of reference substance (mgO₂/L after x days):

Bottle No.	0 days	Bottle No.	7 days	Bottle No.	14 days	Bottle No.	21 days	Bottle No.	28 days
11 12	9.29 9.29	13 14	5.69 5.67	15 16	5.47 5.52	17 18	5.42 5.69	19 20	5.62 5.66
Mean	9.29		5.68		5.50		5.56		5.64

 

Dissolved oxygen of test substance (mgO₂/L after x days):

Bottle No.	0 days	Bottle No.	7 days	Bottle No.	14 days	Bottle No.	21 days	Bottle No.	28 days
21 22	9.28 9.29	23 24	8.99 9.05	25 26	8.97 8.76	27 28	8.76 8.83	29 30	8.73 8.76
Mean	9.29		9.02		8.87		8.80		8.75

 

Dissolved oxygen of toxicity control (mgO₂/L after x days):

Bottle No.	0 days	Bottle No.	7 days	Bottle No.	14 days	Bottle No.	21 days	Bottle No.	28 days
31 32	9.29 9.28	33 34	5.82 5.75	35 36	5.39 5.43	37 38	5.36 5.47	39 40	5.41 5.14
Mean	9.29		5.79		5.41		5.42		5.28

 

DO DEPLETION: % DEGRADATION

Test substance Test concentration: 4.0 mg/L ThOD: 1745 mg/g	DO Depletion after n days (mg/L)
	7 d	14 d	21 d	28 d
No. 1: (mt0-mtx) – (mb0-mbx)	0.00	0.03	0.13	0.22
No. 2: (mt0-mtx) – (mb0-mbx)	0.00	0.25	0.07	0.20
D1: % Degradation	0	0	2	3
D2: % Degradation	0	4	1	3
D,Mean	0	2	2	3

 

Reference substance Test concentration: 2.9 mg/L ThOD: 1665 mg/g	DO Depletion after n days (mg/L)
	7 d	14 d	21 d	28 d
No. 1: (mt0-mtx) – (mb0-mbx)	3.27	3.54	3.48	3.34
No. 2: (mt0-mtx) – (mb0-mbx)	3.29	3.49	3.21	3.30
D1: % Degradation	68	73	72	69
D2: % Degradation	68	72	66	68
D,Mean	68	73	69	69

 

Toxicity control*	DO Depletion after n days (mg/L)
	7 d	14 d	21 d	28 d
No. 1: (mt0-mtx) – (mb0-mbx)	3.14	3.62	3.54	3.55
No. 2: (mt0-mtx) – (mb0-mbx)	3.20	3.57	3.42	3.81
D1: % Degradation	27	31	30	30
D2: % Degradation	27	30	29	32
D,Mean	27	31	30	31

*In the toxicity control 4.0 mg/L test substance and 2.9 mg/L reference substance were used.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Within the test period of 28 days, a degradation of 3% was determined for Jasmaprunat. The substance therefore has to be classified as "Not Readily Biodegradable".

Executive summary:

Within the test period of 28 days, a degradation of 3% was determined for Jasmaprunat. The substance therefore has to be classified as "Not Readily Biodegradable".

The method was a closed-bottle test in accordance with Council Directive 92/69 EEC, Method C.4-E

Description of key information

The substance was determined not to be readily biodegradable: attained 3 % degradation after 28 days in a study conducted to EU method C.4-E (closed bottle test).

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable, not fulfilling specific criteria

Type of water:

freshwater

Additional information

The substance was determined not to be readily biodegradable and attained 3 % degradation after 28 days in a study conducted to EU method C.4-E (closed bottle test). In an inherent biodegradability study conducted to OECD method 302C, the substance was shown to undergo 43 % biodegradation after 48 days in the test conditions. Biodegradation started on day 3 and reached a plateau at about 40 % on day 11.