Thyme, Thymus zygis, ext.

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 february 2018 to 3 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

Test material information

1

Reference substance name:

Thyme, Thymus zygis, ext.

EC Number:

285-397-0

EC Name:

Thyme, Thymus zygis, ext.

Cas Number:

85085-75-2

Molecular formula:

not relevant for a UVCB substance

IUPAC Name:

Thyme, Thymus zygis, ext.

Test material form:

liquid: volatile

Details on test material:

UVCB

Specific details on test material used for the study:

batch number LS104077

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.
date of sampling : 22 feb 2018

Duration of test (contact time):

28 d

Details on study design:

According to the study monitor, the test item was poorly soluble in water, it will be introcuced directly in the test flasks. The test item "red thyme oil" was tested at 100 mg/L in mineral medium. The test medium was the mineral medium, aweakly saline aqueous medium.
Concentration of 100 mg/L

Reference substance

Reference substance:

other: sodium benzoate

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Remarks:

average

Value:

57.14

Sampling time:

28 d

Details on results:

Based ibn ThODNH4, the degradation rate of the test item "RED THYME OIL" do not reach 60% within the 10-day window and after 28 days of incubation the biodegradation was 57.14% (55.88% to 57.94%).
The results obtained show that the test item is not considered to be readly biodegradable following the ThODNH4 after 28 days of incubation.
Under condition of OECD Guideline 301F, the test item "RED THYME OIL", is not considered to be readly biodegradable.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

Flask 9 were inconsistent so, the data observed were unusable during the test. This deviation has no incidence on study results.

Interpretation of results:

not readily biodegradable

Conclusions:

Based on ThODNH4, the degradation rate of the test item "RED THYME OIL" do not reach 60% within the 10-day window and after 28 days of incubation the biodegradation was 57.14% (55.88% to 57.94%).
The results obtained show that the test item is not considered to be readily biodegradable following the ThODNH4 after 28 days of incubation.
Under conditions of OECD Guideline 301F, the test item "RED THYME OIL", is not considered to be readily biodegradable.