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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:
November 8 - December 13, 2016
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2016
Report Date:
2016

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: flakes
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Mitsubishi-Kagaku Foods Corporation
- Expiration date of the lot/batch: March 27, 2018
- Purity test date: October 14, 2016


STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: < 15 degrees C, protected from light

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
sewage, predominantly domestic (adaptation not specified)
Remarks:
66% urban, 34% industrial
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): San Rocco - Monza
- Storage conditions: aerobic
- Preparation of inoculum for exposure: The muds were allowed to mix and settle. They were then centrifuged, washed, and analyzed.
- Initial cell/biomass concentration: 4 mg/L
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
20.38 g/L
Based on:
TOC
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
inorg. C analysis
Details on study design:
TEST CONDITIONS
- Composition of medium: 10 mL of a solution containing potassium dihydrogenphosphate (8.50 g/L), dipotassium hydrogenphosphate (21.75 g/L), disodium hydrogenphosphate dihydrate (33.40 g/L), ammonium chloride (0.50 g/L); 1 mL of a solution containing calcium chloride dihydrate (36.40 g/L); 1 mL of solution containing magnesium sulfate heptahydrate (22.50 g/L); and 1 mL of solution containing iron chloride (III) hexahydrate (0.25 g/L)
- Test temperature: 20 +/- 2 degrees C
- Suspended solids concentration: 4 mg/L
- Continuous darkness: yes
- Other: stirring

TEST SYSTEM
- Culturing apparatus: bottles
- Number of culture flasks/concentration: 17 (11 with test substance and reference substance)
- Measuring equipment: TOC analyzer with an infrared gas analyzer
- Test performed in closed vessels: yes

SAMPLING
- Sampling frequency: Days 0, 1, 4, 14, 21, and 28
- Sampling method: 12 hrs prior, the reaction in one bottle would be stopped with addition of 6 mL 1 M sodium hydroxide.
- Sample storage before analysis: samples were diluted with deionized water


CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Toxicity control: yes
Reference substance
Reference substance:
benzoic acid, sodium salt

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (inorg. C analysis)
Value:
6
Sampling time:
1 d
Parameter:
% degradation (inorg. C analysis)
Value:
54
Sampling time:
4 d
Key result
Parameter:
% degradation (inorg. C analysis)
Value:
78
Sampling time:
14 d
Parameter:
% degradation (inorg. C analysis)
Value:
80
Sampling time:
21 d
Parameter:
% degradation (inorg. C analysis)
Value:
102
Sampling time:
28 d

BOD5 / COD results

Results with reference substance:
The reference substance biodegraded 99% in 14 days. The test was therefore considered valid.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
The substance LMDT is readily biodegradable.
Executive summary:

LMDT was tested for biodegradability in an OECD guideline 301 test. LMDT biodegraded 78% in 14 days, and 102% degraded in 28 days. LMDT is readily biodegradable.