2-cyclohexylethyl acetate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

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 (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2-cyclohexylethyl acetate

EC Number:

244-543-3

EC Name:

2-cyclohexylethyl acetate

Cas Number:

21722-83-8

Molecular formula:

C10H18O2

IUPAC Name:

2-cyclohexylethyl acetate

Specific details on test material used for the study:

6.1 Test Item
Designation in Test Facility: 17112908G
Date of Receipt: 29. Nov. 2017
Condition at Receipt: Room temperature, in proper conditions
6.1.1 Specification
The following information concerning identity and composition of the test item was provid-ed by the sponsor.
Name Cyclohexyl ethyl acetate
Batch no. CP014-171101
Appearance colorless and transparent liquid
Composition Cyclohexyl ethyl acetate
CAS No. 21722-83-8
EINECS-No. 244-543-3
Molecular formula C10H18O2
Molecular weight 170.25 g/mol
Purity 99.85 %
Homogeneity homogeneous
Vapour pressure unknown
Stability in solvents unknown
Solubility in solvents unknown
Production date 01. Nov. 2017
Expiry date 30. May 2019
Storage Room Temperature (20 ± 5 °C)

6.1.2 Storage in Test Facility
The test item was stored in a tightly closed vessel at room temperature (20 ± 5 °C).

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

Activated sludge from a biologic sewage treatment plant was used. The chosen plant is treating mostly household sewage.
The sludge was taken from the activation basin of the sewage treatment plant, In den Seewiesen, 67435 Edenkoben.
Date of collection: 09. May 2018, batch no:20180509.
The sludge was filtrated, washed with medium 2x, and re-suspended in test medium. It was then aerated.
The dry matter was determined as 3880mg suspended solids/L.

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial conc.:

ca. 39 mg/L

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance

Reference substance:

benzoic acid, sodium salt

Remarks:

positive control

Results and discussion

Test performance:

All validity criteria were met.

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 55

Sampling time:

10 d

Remarks on result:

other: When applying the 10-day-window, the test item Cyclohexyl ethyl acetate is not readily biodegradable following OECD 301F/EU C.4-D.

Details on results:

All validity criteria were met.
Oxygen consumption in the blank controls and in the positive controls was normal, indicating that the test system has worked properly.
As a plateau of degradation was reached it is considerable, that the maximal degradation of the test item due to the test conditions was reached.
The ThOD of the test item was calculated and based on molecular formula of the test item, given by the sponsor. The 10-day-window began on day 1 (this is stated as lag phase), at its end (day 11), 55 % were reached, missing the pass level of 60 % given in the OECD guideline.
As a plateau of degradation was reached it is considerable, that the maximal degradation of the test item due to the test conditions was reached.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Therefore, when applying the 10-day-window, the test item Cyclohexyl ethyl acetate is considered as not readily biodegradable following OECD 301F/EU C.4-D.
As degradation surpassed 60 % in the course of the test, Cyclohexyl ethyl acetate is con-sidered as ultimately biodegradable, within 28 days.