Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Data from handbook or collection of data.

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Biodegradation and bioaccumulation data of existing chemicals based on the CSCL Japan.
Author:
Edited by Chemicals Inspection and Testing Institute, Japan.
Year:
1992
Bibliographic source:
Chemical Products Safety Division, Basic Industries Bureau, Ministry of International Trade and Industry, Japan.
Reference Type:
other: MITI database
Title:
No information
Author:
NITE
Year:
2012
Bibliographic source:
Copyright 2002-2012 National Institute of Technology and Evaluation Internet link:http://www.safe.nite.go.jp/english/sougou/view/SystemTop_en.faces

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))
Deviations:
not specified
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
Veratrole

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, non-adapted
Details on inoculum:
Source of inoculum:

Activated sludge samples were obtained from 10 locations in Japan, four times per year. Samples were taken from municipal and industrial sewage treatment plants, rivers, lakes and the sea.

Surface water and surface soil samples were collected from rivers, lake and sea.

Mixing of fresh and old activated sludge:

5 litres of the filtrate of the supernatant of an activated sludge in current use were mixed with 500 ml of the filtrate of the supernatant from the newly collected sample. The mixture was cultured at pH 7.0 ± 1.0 under aeration.

Culturing:

Aeration was stopped 30 minutes before one third of the volume of sludge mixture was removed. This was replaced with an equal volume of dechlorinated water and aeration started again prior to addition of synthetic sewage. This process was repeated once per day at 25±2°C.

Synthetic sewage:

Glucose, peptone and monopotassium phosphate dissolved in dechlorinated water at a concentration of 5% w/v. pH was adjusted to 7.0±1.0 with sodium hydroxide.

Reference substance:
Biodegradation testing with a reference substance (aniline) was used to confirm the activity of the inoculum.
Duration of test (contact time):
14 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
Composition of medium: As prescribed by JIS K 0102-1986-21, pH adjusted to 7.0

Test temperature: 25±1°C

Aeration of dilution water: No data

Reference substance: 100 mg/l aniline

TEST SYSTEM

Preparation of test solutions: test or reference substance (30 mg) was added to 300 ml culture medium. Activated sludge was added so that suspended solids concentration was 30 mg/l.

Measuring equipment: Dissolved oxygen concentrations were measured using a coulometer from Ohkura Electric Co., Ltd

Test solutions were stirred using a magnetic stirrer.

SAMPLING

- Other: No data

CONTROL AND BLANK SYSTEM

- Inoculum blank: Yes

- Abiotic sterile control: No

- Toxicity control: No

Reference substance
Reference substance:
aniline

Results and discussion

% Degradation
Parameter:
% degradation (O2 consumption)
Value:
95 - 97
Sampling time:
14 d
Details on results:
No more data

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Remarks:
(please refer to Conclusions below)
Interpretation of results:
readily biodegradable
Conclusions:
The report states that activity of the inoculum was checked by biodegradation testing of the reference substance aniline, which was expected to exceed 60% degradation by BOD by Day 14. However, results are not reported for individual studies therefore it is not possible to confirm that the pass level was achieved for this study.

No kinetic data are reported for the test substance therefore it is not possible to confirm whether the 10-day window criterion was met. However, the substance attained 95 – 97% degradation in 14 days and it is therefore considered to be readily biodegradable.

There are insufficient data to confirm whether degradation of replicates was ±20% at the end of the test.
Executive summary:

The biodegradability of Veratrole was tested in a MITI test (OECD 301C).

After 14 days, the percentage of biodegradation was 95 - 97% based on oxygen consumption.

In these conditions, Veratrole is considered as readily biodegradable.