methyl 5-(bis(methoxycarbonylmethylamino))-4-cyano-3-methoxycarbonylmethylthiophen-2-carboxylate

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:

2004

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

yes (incl. QA statement)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

other: inoculum based on aerated sludge

Details on inoculum:

inoculum collected from a water treatment plant, containing effluent from predominantly domestic origin and then aerated for 6 days. Inoculum concentration : 12.0 mg/L (dry weight) in all test vessels.

Duration of test (contact time):

28 d

Details on study design:

The test item was dissolved in reconstituted water (OECD mineral medium) prepared from deionised water with a conductivity < 10 microS/cm.
Five flasks were used to determine the quantity of carbon dioxide evolved by the degradation of the test item:
- two flasks containing the inoculum (inoculum blanks),
- two flasks containing the test item (at 10.0 mg/L of total organic carbon (TOC) and inoculum (test solutions)
- one flask containing the reference item (sodium acetate at 10.0 mg/L of TOC) and inoculum (procedure control)
Measurements of CO2: days 1, 4, 6, 8, 11, 14, 19, 22, 25 and 29.

The inoculum consisted of sewage sludge sampled from the aeration tank of a sewage treatment plant and then aeratedfor days. Inoculum concentration was 12.0 mg/L (dry weight) in all test vessels.
CO2 scrubbed air was bubbled through the flasks over the test period.
Environmental parameters were recorded as:
pH: 7.54 to 7.93,
temperature: 20 to 24 C.

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

% Degradation

Value:

12

Sampling time:

28 d

Remarks on result:

other: over the whole test period

Details on results:

Cumulative percentage of biodegradation: See table in Overall remarks and attachements window.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

At the end of the test, the biodegradation of Thiofestermet reached 12%. Thiofestermet is therefore not readily biodegradable in the 28-day modified Sturm test.