3-ethyloxetane-3-methanol

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Activated sludge was obtained from Totness Sewage Treatment works, Devon, the day before the start of exposure of test and reference substances. This works treats sewage of predominantly domestic origin.
The activated sludge was settled and the supernatent decanted. Sludge was washed by centrifugation for 5 minutes, the supernatent was decanted and made up to the original volume by addition of mineral media solution. The washing was repeated twice more and the sludge was aerated at room temperature until the it was used in the test.

Duration of test (contact time):

28 d

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

Not applicalbe

Reference substance:

aniline

Test performance:

The biodegradation of aniline was greater than 70% after 14 days, confirming the viability of the activated sludge. The PMS probe was calibrated on day 0 and was found to be within range. Continuous monitoring of the room temperature was started on day 3 and showed that the temperature remained within the range of 22.5 ±2.5oC during the study. As such, the test should be considered to be valid.

Key result

Parameter:

% degradation (DOC removal)

Value:

< 1

Sampling time:

28 d

Details on results:

Trimethylolpropane was less than 1% degraded after 28 days. As the biodegradation of the test substance was less than 70% it is classified as non-biodegradable.

Results with reference substance:

The reference substance (aniline) was greater than 70% degraded after 14 days, confirming the viability of the inoculum.

Table 1: Test substance dissolved organic carbon results

Test time	Blank (mg/l)	Measured DOC (mg/l)	Blank corredted DOC (mg/l)	Biodegradation (%)
3h	20	280	260	0
3d	4.3	281	276	<1
7d	2.6	277	274	<1
14d	5.7	280	274	<1
21d	8.4	284	276	<1
27d	9.0	286	276	<1
28d	9.2	286	277	<1

Table 2: Reference substance dissolved organic carbon results

Test time	Blank (mg/l)	Measured DOC (mg/l)	Blank corredted DOC (mg/l)	Biodegradation (%)
3h	20	288	268	-
3d	4.3	258	254	5.3
7d	2.6	14	11	96
14d	5.7	9.3	3.6	99
21d	8.4	12	3.3	99
27d	9.0	8.5	<1	100
28d	9.2	9.2	0.0	100

Validity criteria fulfilled:

yes

Interpretation of results:

not inherently biodegradable

Conclusions:

After 28 days less than 1% biodegradation of the test substance ocurred based on dissolved organic carbon removal. As such, Trimethylolpropane oxetane is not considered to be inherently biodegradable.

Executive summary:

A 28 -day OECD 302B Zahn-Wellens test was carried out to assess the inherent biodegradability of Trimethylopropane oxetane. The test measured the removal to dissolved organic carbon (DOC) to determine the percentage degradation of the test substance. The DOC was measured after 3 hours and then again on days 3, 7, 14, 21, 27 and 28. The pH was between 6.5 and 8.0 and the temperature was 22.5 ±2.5oC throughout the test. Aniline was used as a refence substance to confirm the viability of the activated sludge.

The test substance was found to be <1% degraded after 28 days. As biodegradtion of Trimethylolpropane was less than 70% the substance is considered not to be inherently biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Activated sludge was obtained from 10 seperate locations across Japan in September 1996.
The filtrate (5L) of the supernatent of the activated sludge used was mixed together with each of the filtrate (500 mL) of the supernatant of a newly collected sludge. The mixed filtrate (10L) was aerated after the pH value of the mixture was adjusted to 7.0 ±1.0.
After ceasing aeration of the sludge mixture for approximately 30 minutes, around 1/3 of the supernatent was removed. An equal volume of dechlorinated water was then added to the remaining portion.

Duration of test (contact time):

28 d

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

Not applicalbe

Reference substance:

aniline

Test performance:

The biodegradation of aniline was greater than 70% after 14 days, confirming the viability of the activated sludge. The PMS probe was calibrated on day 0 and was found to be within range. Continuous monitoring of the room temperature was started on day 3 and showed that the temperature remained within the range of 22.5 ±2.5oC during the study. As such, the test should be considered to be valid.

Parameter:

other: BOD

Value:

<= 1

Sampling time:

28 d

Key result

Parameter:

% degradation (TOC removal)

Value:

<= 1

Sampling time:

28 d

Parameter:

other: GC

Value:

<= 6

Sampling time:

28 d

Details on results:

The test substance was partially converted into 3-ethyl-3-oxetanoic acid. The test substance and the acid were not readily biodegraded by microorganisms.

Results with reference substance:

The reference substance (aniline) was greater than 70% degraded after 14 days, confirming the viability of the inoculum.

Table 1: Test substance biodegradation results

Method	Biodegradation vessel 3	Biodegradation Vessel 4	Biodegradation vessel 5	Average
BOD	1	2	1	1
TOC	1	1	1	1
GC	8	4	4	6

Validity criteria fulfilled:

yes

Interpretation of results:

other: Not readily biodegradable

Conclusions:

After 28 days less than 1%, 1% and 6% biodegradation of the test substance ocurred based on BOD, TOC and GC methods respectively. As such, the test substance is not considered to be readily biodegradable.

Executive summary:

A 28 day OECD 301C test was carried out to assess ready biodegradability of the test substance.

Biodegradation was measured by biological oxygen demand (BOD), determination of dissolved organic carbon (TOC), determination of test substance concentrations by gas chromatography and determination of 3-ethyl-3-oxeanoic acid by high performance liquid chromatography (HPLC).

After 28 days less than 1%, 1% and 6% biodegradation of the test substance ocurred based on BOD, TOC and GC methods respectively. As such, the test substance is not considered to be readily biodegradable.

Description of key information

In an OECD 301C ready biodegradability study, the test substance showed less than 1%, 1% and 6% biodegradation of the test substance based on BOD, TOC and GC methods respectively The test substance is therefore not considered to be readily biodegradable.

The test substance also showed less than 1% degradation in an OECD 302B inherent biodegradability test. As such the substance is considered to be non-biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

A 28 day OECD 301C ready biodegradability study was conducted. After 28 days less than 1%, 1% and 6% biodegradation of the test substance occurred based on BOD, TOC and GC methods respectively. As such, the test substance is not considered to be readily biodegradable.

A 28 -day OECD 302B Zahn-Wellens test was also carried out to assess the inherent biodegradability of 3-ethyloxetane-3-methanol. The test measured the removal to dissolved organic carbon (DOC) to determine the percentage degradation of the test substance. The DOC was measured after 3 hours and then again on days 3, 7, 14, 21, 27 and 28. The pH was between 6.5 and 8.0 and the temperature was 22.5 ±2.5oC throughout the test. Aniline was used as a reference substance to confirm the viability of the activated sludge.

The test substance was found to be <1% degraded after 28 days. As biodegradation of 3-ethyloxetane-3-methanol was less than 70% the substance is considered not to be inherently biodegradable.