Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to official test guidelines (OECD 301C), and in compliance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 835.3110 (Ready Biodegradability)
Version / remarks:
“Method for Testing the Biodegradability of Chemical Substances by Microorganisms” stipulated in the “Testing Methods for new Chemical Substances” (November 21, 2003, Yakushokuhatsu No.1121002, November 13, 2003 Seikyoku No.2, Kanpokihatsu No.031121002)
Deviations:
no
GLP compliance:
yes
Remarks:
The test report cites Japanese and OECD GLP standards.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 3-Methyl-3-methoxybutyl acetate
- Analytical purity: 99.1% (GC)
- Lot/batch No.: AQ01
- Storage condition of test material: Cool in the dark

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge (adaptation not specified)
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Sludge was sampled from a total of ten Japanese sites; 4 sewage treatment plants, three river locations, and three lake / sea bay locations.
- Method of cultivation: Filtrate of the activated sludge was cultivated for c.a. 3 months was mixed with the filtrate of a mixture of the sludge collected from each of the 10 locations. The mixed filtrate was aerated and then the pH of the mixture was adjusted to pH 7.0 ± 1.0.
- Storage length: Sludge kept for 18 - 24 hours after the addition of synthetic water was used.
- Concentration of sludge: 3920 mg/L suspended solids.
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
100 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
O2 consumption
Details on study design:
TEST CONDITIONS
- Test temperature: 25±1°C.
- pH: 7.0
- pH adjusted: pH adjustment was carried out on the inoculum, prior to addition of the test material.
- Suspended solids concentration: 30 mg/L suspended solids.
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 300 mL vessels in a temperature controlled bath. Each test solution was stirred by a magnetic stirrer.
- Number of culture flasks/concentration: 3
- Measuring equipment: The change in Biochemical Oxygen Demand (BOD) of the test solution was measured and recorded using a data processing machine
- Details of trap for CO2 and volatile organics if used: Soda lime

SAMPLING
- Sampling frequency: Automatic measurement of BOD

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

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (O2 consumption)
Remarks:
(Biochemical Oxygen Demand, BOD)
Value:
90
Sampling time:
28 d
Parameter:
% degradation (DOC removal)
Value:
97
Sampling time:
28 d
Parameter:
% degradation (test mat. analysis)
Value:
100
Sampling time:
28 d
Remarks on result:
other: Determination of test substance in test solutions at the end of the biodegradation test by GC analysis.

BOD5 / COD results

Results with reference substance:
Aniline was found to be 67% degraded by day 7, and 71% degraded by day 14, meeting the acceptability criteria for both of these time points.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
other: biodegradable but not enough information to assess readily or inherent
Conclusions:
The test substance was biodegraded by microorganisms under the present test conditions.