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: official guideline method, GLP with certificate, good documentation, identity of substance clear with details on its purity

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))
Principles of method if other than guideline:
In the study report is stated: The test was conducted according to the "Method for Testing the Biodegradability of Chemical Substances by microorganisms" stipulated in the "Testing Methods for New Chemical Substances" (July 13, 1974, Kanpogyo No. 5, Planning and Coordination Bureau, Environment Agency, Yakuhatu No. 615, Pharmaceutical Affairs Bureau, Ministry of Health and Welfare, and 49 Kikyoku No. 392, Basic Industry Bureau, Ministry of International Trade and Industry, Japan). The test method is very similar to one stipulated in the OECD Guideline for Testing of Chemicals "Ready Biodegradability: 301C, Modified MITI Test (I)" (Revised July 17, 1992).
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Test material as stated in study report ("Name"): Ethyl methyl carbonate
Molecular formula: C4H8O3
Molecular weight: 104.11
Purity: 99.8 %
Supplier of the test substance: Ube Industries, Ltd.
Lot number of the test substance: MEC-27452
Identification: Two IR spectra, obtained from the sponsor and from our laboratory were confirmed to be identical
Storage: Chilled dark place

Remark of the author of this IUCLID dossier concerning the substance identity:
Every page of the copy of the study report contains an annotation referring to the data sharing agreement in place between the licensee that uses this study report and the data owner. In this data sharing agreement the identity of the chemical substance is specified with "Ethyl Methyl Carbonate - EC No. 433-480-9, CAS Nr. 623-53-0".

Study design

Oxygen conditions:
anaerobic
Remarks:
Culture apparatus: Closed system oxygen consumption measuring apparatus
Inoculum or test system:
activated sludge (adaptation not specified)
Details on inoculum:
Concentration of activated sludge: 30 mg/L (as the concentration of suspended solid)
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
100 mg/L
Based on:
test mat.
Details on study design:
Test solutions: (a) Water + test substance (297 mL of purified water mixed with 3 mL of 10 g/L test substance) (n=1, Vessel No. 2)
(b) Sludge + test substance (297 mL of basal culture medium mixed with 3 mL of 10 g/L test substance) (n=3, Vessel No. 3, 4 and 5)
(c) Sludge + aniline (300 mL of basal culture medium added with 29.5 µL (30.0 mg) aniline) (n=1, Vessel No. 1)
(d) Control blank (300 mL of basal culture medium without test substance or aniline) (n=1, Vessel No. 6)

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (TOC removal)
Value:
92
Sampling time:
28 d
Parameter:
other: Biodegradation by biochemical oxygen demand (BOD)
Value:
98
Sampling time:
28 d
Parameter:
% degradation (test mat. analysis)
Remarks:
Determination of test substance by means of a gas chromatography (GC)
Value:
100
Sampling time:
28 d

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
In the study report a final false statement is given: "It is concluded that the test substance was not biodegraded by microorganisms under the present test conditions." The actual results of the study point to ready biodegradability. After inquiring about the validity of the given statement the author of this IUCLID dossier got the confirmation from the data owner that this is a false statement in the study report. The substance is regarded as ready biodegradable by microorganisms as it degraded by > 70 % within 28 d (in accordance with: Guidance on information requirements and chemical safety assessment, May 2008; REGULATION (EC) No 1272/2008, 4.1.2.9. Rapid degradability of organic substances (16 Dec 2008))
Chapter R.7b: Endpoint specific guidance