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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:
27 feb 2018 to 4 april 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report date:
2018

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
GLP compliance:
yes

Test material

Constituent 1
Reference substance name:
Thyme, Thymus mastichina, ext.
EC Number:
284-294-8
EC Name:
Thyme, Thymus mastichina, ext.
Cas Number:
84837-14-9
Molecular formula:
Not relevant for UVCB
IUPAC Name:
Thyme, Thymus mastichina, ext.
Test material form:
liquid: volatile
Specific details on test material used for the study:
batch number LS104075
manufacturing date : june 2017
deadline to use : june 2021
purity 100%
test item state : Colorless liquid
received quantity : 100 mL
packaging : Glass flask
storage condition : Room temperature (20 ± 5°C)

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
water treatment plant "STEP de Lille" 33290 Blanquefort (France) - The inoculum was a fresh sample of activated sludge and was collected from the aeration tank of a sewage treatment plant receiving predominantly domestic sewage.
The inoculum will correspond to a fresh sample of activated sludge and will be collected from the aeration tank of a sewage treatment plant receiving predominantly domestic sewage.
Laboratory preparation: A filtration through a fine sieve (about 1 mm) will be performed in order to remove coarse particles. After removal of any coarse particles, the sludge will be washed by decantation in a mineral medium until sludge is considered free from excess substrate or inhibitor.
Inoculum pre-conditioning: Pre-conditioning will consist in aerating sludge (in mineral medium) for 5-7 days before the test and at the test temperature.
Duration of test (contact time):
28 d
Details on study design:
The medium was prepared from concentrated stock solutions in ultrapure water as decribed in the guideline.
Reference substance
Reference substance:
other: sodium benzoate

Results and discussion

% Degradation
Key result
Parameter:
% degradation (O2 consumption)
Remarks:
average
Value:
64.45
Sampling time:
28 d
Details on results:
Based on ThOD (NH4), the degradation rate of the test item "marjoram oil" do not reach 60% within the 10-day window, nethertheless, after 28 days of incubation the biodegradation was 64.45% (61.26 % to 69.82%).
The results obtained show that the test itemis considered to be biodegradable following the ThOD (NH4), after 28 days of incubation.
Under conditions of OECD Guideline 301F, the test item "marjoram oil" is considered to be biodegradable.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable, but failing 10-day window
Conclusions:
The results obtained show that the test item is considered to be biodegradable following the ThOD (NH4), after 28 days of incubation.
Under conditions of OECD Guideline 301F, the test item "marjoram oil" is considered to be biodegradable.
Executive summary:

The aim of the study was to determine the effects of the test idem "marjoram oil" according to the OECD 301F guideline, ready biodegradability within an experimental period of 28 days by respirometric method.

Based on ThOD (NH4), the degradation rate of the test item "marjoram oil" do not reach 60% within the 10-day window, nethertheless, after 28 days of incubation the biodegradation was 64.45% (61.26 % to 69.82%).

The results obtained show that the test item is considered to be biodegradable following the ThOD (NH4), after 28 days of incubation.

Under conditions of OECD Guideline 301F, the test item "marjoram oil" is considered to be biodegradable.