(cyclohex-3-en-1-yl)methyl 2-hydroxypropanoate

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:

From 2 February, 2017 to 1 May, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(cyclohex-3-en-1-yl)methyl 2-hydroxypropanoate

EC Number:

946-283-2

Cas Number:

1864727-96-7

Molecular formula:

C10H16O3

IUPAC Name:

(cyclohex-3-en-1-yl)methyl 2-hydroxypropanoate

Specific details on test material used for the study:

-Purity: >99%
-Lot number: MB10-55
-Appearance: Coloress liquid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

On-site sludge sampling was carried out at 10 locations in Japan (samples were from surface water and surface soil of rivers, lakes, and inland sea; return sludge from sewage plants). Activated sludge, which was prepared and controlled in the test laboratory according to the test guideline, was used in this study (sampling period: November, 2016, initiation date of use: December 21, 2016). The activated sludge, which was cultivated for 19.5 hours after the addition of the synthetic sewage, was used. The synthetic sewage was prepared according to the following method; glucose, peptone, and potassium dihydrogenphosphate were dissolved in purified water, and the pH of the solution was adjusted to 7.0±1.0. The concentration of suspended solid in the activated sludge was 3980 mg/L.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation 1

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation 2

Parameter followed for biodegradation estimation:

test mat. analysis

Parameter followed for biodegradation estimation 3

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

Test conditions
- Concentration of test substance: 100 mg/L
- Concentration of activated sludge: 30 mg/L (as concentration of suspended solid)
- Volume of test solution: 300 mL
- Incubation temperature: 25±1°C
- Composition of medium: Mineral nutrient solution (pH 7.0) according to the OECD Guideline 301C
Test system
- Test solution with purified water + test substance: n=1
- Test solution with medium + test substance + activated sludge: n=3
- Test solution with medium + activated sludge: n=1
- Test solution with medium + aniline + activated sludge: n=1

Reference substance

Reference substance:

aniline

Remarks:

100 mg/L in the test solution

Results and discussion

% Degradation

% Degradation 1

Key result

Parameter:

% degradation (O2 consumption)

Value:

87

Sampling time:

28 d

% Degradation 2

Key result

Parameter:

% degradation (test mat. analysis)

Value:

100

Sampling time:

28 d

% Degradation 3

Key result

Parameter:

% degradation (DOC removal)

Value:

89

Sampling time:

28 d

Details on results:

Percentage biodegradation on 28 days
- O2 consumption: 87%, 87% and 87 %
- Test mat. analysis: 100%, 100% and 100 %
- DOC removal: 89%, 89% and 88%

BOD5 / COD results

Results with reference substance:

Percentages of biodegradation of aniline were 71% on 7 days and 78% on 14 days. These values
met the validity criteria of the test (>40% on 7 days and >65% on 14 days).

Any other information on results incl. tables

The validity criteria of the tests and the values in this test are shown in the following table. This test was

valid because all the values in this test met the criteria.

Table 1. Validity of test conditions

		Value in test	Value of criteria
Difference between extremes of replicate value of percentage biodegradation	Percentage biodegradation by BOD	0%	<20%
	Percentage biodegradation byDOC	1%	<20%
	Percentage bopdegradation by HPLC	0%	<20%
Percentage biodegradation of aniline by BOD	On 7 days	71%	>40%
	On 14 days	78%	>65%
BOD value of control blank	On 28 days	25 mg/L	≤60 mg/L

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Under the test condition of this study, the test item completely disappeared due to microbial action, and 3-cycrohexene-1-methanol and lactic acid were produced. Afterward, lactic acid underwent biodegradation and disappeared completely. Although 3-cyclohexene-1-methanol also disappeared completely, the degradation products A and B having a cyclohexane ring were detected. The percentage biodetradation by BOD (87%) and by DOC (89%) was high, and it indicated that the biodegradation products would eventually undergo biodegradation completely.