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Environmental fate & pathways

Biodegradation in water: screening tests

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Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
weight of evidence
Study period:
1984
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to the appropriate OECD test guideline, and in compliance with GLP.

Data source

Reference
Reference Type:
other: Study report
Title:
Unnamed
Year:
1984
Report date:
1984

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Reference substance name:
[ethylenebis[nitrilobis(methylene)]]tetrakisphosphonic acid, sodium salt
EC Number:
244-742-5
EC Name:
[ethylenebis[nitrilobis(methylene)]]tetrakisphosphonic acid, sodium salt
Cas Number:
22036-77-7
IUPAC Name:
22036-77-7

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
Activated sludge from the HRC sewage treatment plant. The nature of the influent to this treatment plant is not known.

The activated sludge was filtered through Whatman No 1 paper (first 200 ml discarded) and the filtrate was kept aerated until used. 
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
40 other: mg C/l
Based on:
DOC
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
DOC removal
Reference substance
Reference substance:
benzoic acid, sodium salt

Results and discussion

% Degradation
Parameter:
% degradation (DOC removal)
Value:
0
Sampling time:
21 d
Remarks on result:
other: Data for days 27-28 of the test period were not recorded due to contamination by a broken pipe.
Details on results:
Briquest 422-25S attained 0% degradation after 21 days and was not considered readily biodegradable under OECD
Guideline No. 301-E. The control substance attained 85% degradation after 14 days and 97% after 28 days, confirming
suitability of the inoculum and culture conditions.

Degradation products: no

BOD5 / COD results

Results with reference substance:
Day 7: 79%
Day 14: 85%
Day 28: 97%

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed