Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: inherent biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
20 June 2000 - 25 July 2000
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to OECD Guideline and GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2000
Report Date:
2000

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
other: solid
Details on test material:
Batch No: 62/3727
Appearance: solid, white
Purity: 98.1%

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, industrial, non-adapted
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
237 mg/L
Based on:
other: DOC/g test substance

Results and discussion

% Degradation
Parameter:
% degradation (DOC removal)
Value:
0
Sampling time:
28 d
Details on results:
There was no degradation after 28 days of incubation detecable. Therefore the test substance must be considered to be not biodegradable under the chosen conditions. The control substance was degraded >99% within 10d. The threshold of >70% was met within 7d of incubation (99%). Accordingly, the test is considered to be valid. No bacterial toxicity was observed at the used concentration.

Any other information on results incl. tables

Table 1: Results of Testing Biodegradability according to "modified Zahn Wellens-Test" OECD 302 B

Date

Time (Days)

DOCnetto(mg/L)

Degradation (%)

06-27-00

06-27-00

06-28-00

06-30-00

07-04-00

07-07-00

07-11-00

07-14-00

07-18-00

07-21-00

07-24-00

07-25-00

0

3h

1

3

7

10

14

17

21

24

27

28

256.75

247.12

248.72

255.51

239.78

273.01

271.76

271.27

284.95

273.96

264.14

271.39

-

-

-

-

3

-

-

-

-

-

-

-

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
Under the chosen conditions no degradation after 28 days is calculated. Therefore the test substance must be considered to be "not biodegradable". The control substance Na-benzoate was degraded by >99% within 10d. The threshold of "inherent biodegradability" of >70% was met within 7d of incubation (99%).
Executive summary:

The substance was tested for inherent biodegradability according to OECD 302 B, (Modified Zahn-Wellens Test) and GLP in year 2000. Under the chosen conditions no degradation after 28 days is calculated. Therefore the test substance must be considered to be "not biodegradable". The control substance Na-benzoate was degraded by >99% within 10d. The threshold of "inherent biodegradability" of >70% was met within 7d of incubation (99%). Therefore, the test is considered to be valid. No bacterial toxicity was observed at the used concentration.