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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: Study according to EC guideline.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1997

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method C.4-B (Determination of the "Ready" Biodegradability - Modified OECD Screening Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
name: Cyanamide, (4,5-dihydroxy-2-thiazolyl)-
molecular formula: C4 H5 N3 S
molecular weight: 127.2
physical state: solid
analytical purity: 98 %

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
sewage, domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): effluent of laboratory scale unit receiving
sewage from the south Wupper area water authority
- Method of cultivation: none
- Pretreatment: Separation of coarse particles by filtration
- Concentration of sludge: 0.5 ml/1
Duration of test (contact time):
29 d
Initial test substance concentration
Initial conc.:
19 mg/L
Based on:
DOC
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
DOC removal
Details on study design:
TEST CONDITIONS
- Composition of medium: mineral medium
- Test temperature: 22°C +/- 2°C

TEST SYSTEM
- Number of culture flasks/concentration: 2

SAMPLING
- Sampling frequency: on day 0, 7, 14, 21, 28 and 29

CONTROL AND BLANK SYSTEM
- Toxicity control: yes
Reference substance
Reference substance:
aniline

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (DOC removal)
Value:
3
Sampling time:
7 d
Parameter:
% degradation (DOC removal)
Value:
0
Sampling time:
14 d
Parameter:
% degradation (DOC removal)
Value:
1
Sampling time:
21 d
Parameter:
% degradation (DOC removal)
Value:
4
Sampling time:
28 d
Parameter:
% degradation (DOC removal)
Value:
2
Sampling time:
29 d

BOD5 / COD results

Results with reference substance:
The reference substance degraded to 96% within 29 days.

Any other information on results incl. tables

test substance % degradation after n days
Flask nr. 0h 7d 14 d 21 d 28 d 29 d
8 0 0 0 1 2 1
9 0 5 0 1 5 3
Mean 0 3 0 1 4 2

reference substance % degradation after n days
Flask nr. 0h 7d 14 d 21 d 28 d 29 d
3 0 100 89 95 97 96
4 0 98 95 94 95 96
Mean 0 99 92 95 96 96

toxicity control % degradation after n days
Flask nr. 0h 7d 14 d 21 d 28 d 29 d
10 0 46 43 48 49 46

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
The substance is considered to be not readily biodegradable according to EC Guideline C.4-B and classified accordingly.