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
Study period:
2017-04-06 - 2017-05-17
Reliability:
1 (reliable without restriction)
Justification for type of information:
guideline study according to GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report Date:
2017

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
Municipal activated sludge from the wastewater treatment plant of Mannheim, Germany. The inoculum was collected on 10 April 2017 from the aeration tank of the plant. A suitable aliquot of the activated sludge suspension was sieved by a finely woven mesh with a mesh size about 1 mm. To reduce the content of inorganic carbon in the blank controls the activated sludge was aerated with carbon dioxide free air for about 48 hours at 22 ± 2° C.
At the day of exposure the suspension was washed one time with drinking water. Therefore the aeration was stopped and the sludge was allowed to settle. After settling the supernatant was discarded and the remaining sludge suspension was filled up with drinking water and the concentration of the sludge was adjusted to 6.0 g/L dry weight.
Initial test substance concentration
Initial conc.:
20 mg/L
Based on:
TOC
Reference substance
Reference substance:
aniline

Results and discussion

% Degradationopen allclose all
Key result
Parameter:
% degradation (CO2 evolution)
Value:
2
Sampling time:
1 d
Key result
Parameter:
% degradation (CO2 evolution)
Value:
47
Sampling time:
6 d
Key result
Parameter:
% degradation (CO2 evolution)
Value:
55
Sampling time:
9 d
Key result
Parameter:
% degradation (CO2 evolution)
Value:
61
Sampling time:
12 d
Key result
Parameter:
% degradation (CO2 evolution)
Value:
64
Sampling time:
20 d
Key result
Parameter:
% degradation (CO2 evolution)
Value:
60 - 70
Sampling time:
28 d

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
The test item has a salt like character consisting of ethanolamine and etidronic acid. From a formal point of view, the registerd substance is readily biodegradable fulfilling the crioteria for ready biodegradation. However, a closer look on the mass balance indicatesthat a stable metabolite may be formed. Whereas the ethanolamine is expected to degrade fast after dissociation in water, the etidronic acid may be stable.