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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
Study period:
2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

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

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)
GLP compliance:
yes

Test material

1
Reference substance name:
Tall oil, polymd., oxidized
EC Number:
683-326-1
Cas Number:
68815-17-8
Molecular formula:
Not applicable (UVCB substance)
IUPAC Name:
Tall oil, polymd., oxidized
Test material form:
liquid

Study design

Inoculum or test system:
other: secondary effluent or with another source such as river water
Duration of test (contact time):
28 d

Results and discussion

Preliminary study:
It was evaluated the behaviour in water of the Test ltem at four nominal concentrations: 0,5 g/l; 1,0 g/l; 5,0 g/l and 10,0 g/1, The Test ltem was added to 100 ml of analytical grade water. The mixture was stirred for t hour. Observation were made immediately after stirring interruption and after 20 hours.
The Test ltem is stably and homogenously dispersible in water at concentration < 5,0 g/l.
It is not soluble nor dispersible at concentration > 10,0 g/1.
% Degradation
Key result
Parameter:
other: % of COD
Value:
61.4
Sampling time:
28 d

BOD5 / COD results

BOD5 / COD
Key result
Parameter:
COD
Value:
61.4 other: % biodegradation

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable, but failing 10-day window
Conclusions:
This Study was performed to assess if the Test ltem, TALL OlL, POLYMD, OXIDIZED, is readily biodegradable. The pass levels for ready biodegradability is 60% of COD. These pass value have to be reached in a 10-d window within the 28-d period. The 10-d window begins when the degree of biodegradation has reached 10% COD and must end before day 28 of the test.
During the test no significant abiotic degradation process had occurred. No considerable toxic effects have been observed.
The Test ltem was rapidly degraded during the first 6 days of the test. Then, the degradation slowed down and progresses with a low rate. At the end of the test it was reached a biodegradation oî 61,4 o/o.
The pass threshold has been overcame but the 1O-day window criteria was not met. According to these data, the Test ltem cannot be therefore considered readily biodegradable.
The shape of the degradation curve suggests that the biodegradation process is not ended.