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
Reliability:
2 (reliable with restrictions)

Data source

Reference
Reference Type:
publication
Title:
The ecotoxicity and biodegradability of lactic acid, alkyl lactate esters and lactate salts.
Author:
Bowmer, C.T., Hooftman, R.N., Hansveit, O.A, Venderbosch, P.W.M and Van der Hoeven, N.
Year:
1998
Bibliographic source:
Chemosphere, Vol. 37, 1317-1333

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method C.5 (Degradation: Biochemical Oxygen Demand)
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Duration of test (contact time):
20 d
Initial test substance concentration
Initial conc.:
4 mg/L
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
O2 consumption

Results and discussion

% Degradation
Parameter:
other: BOD
Value:
ca. 60
Sampling time:
10 h
Details on results:

BOD 20 = 0.60 mg O2 per mg test substance

BOD5 / COD results

BOD5 / CODopen allclose all
Parameter:
BOD5
Value:
0.45 g O2/g test mat.
Parameter:
COD
Value:
0.85 g O2/g test mat.
Parameter:
BOD5*100/COD
Value:
50

Any other information on results incl. tables

Year of BOD5 method: 1998 (unclear if "Year of test guideline" or "Year of study completion".
RM-Freetext:
A7.1.1.2.1-02

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
Interpretation of results:
readily biodegradable, but failing 10-day window
Conclusions:
Lactic acid is readily biodegradable
Executive summary:

The biodegradation of lactic acid and lactate esters was studied. The aim of the study was to provide predicted environmental data for additional alkyl homologues and metal salts. Lactic acid and its alkyl esters were degraded for more than 60% in the ready biodegradability tests and from the data presented, it is evident that lactic acid and the majority of alkyl lactates are readily biodegradable.