trans-(5RS,6SR)-6-amino-2,2-dimethyl-1,3-dioxepan-5-ol

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:

key study

Study period:

11 Apr - 19 May 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: International Standard ISO/8192

Version / remarks:

1986

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: The sludge was collected from the secondary settlement tank from Rungsted sewage plant (this plant does not receive industrial sewage).
- Storage length: The sludge was collected immediately prior to test setup.

Duration of test (contact time):

34 d

Initial conc.:

104 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- pH: 7
- pH adjusted: Yes, daily adjusted to 7 with 1N sodium hydroxide
- Suspended solids concentration: 1.1 g solid matter (dry content)/ L test solution

TEST SYSTEM
- Number of culture flasks/concentration: 2 replicates

SAMPLING
- Sampling frequency: Samples taken at 0 and 3 h and at day 7, 14, 20, 28 and 34.
- Sampling method: Samples were filtered 0.45 µm filter (cellulose nitrate)
- Sample storage before analysis: Samples were frozen prior to analysis

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, 2 replicates
- Abiotic sterile control: yes, 1 replicate (microbial activity was stopped by applying 100 mg/L Mercury chloride)
- Reference substance: yes, 2 replicates (Diethyleneglycol at 100 mg carbon/L)

Reference substance:

other: Diethyleneglycol

Preliminary study:

In order to avoid an inhibitory effect of the test compound on the sludge a modified sludge respiration test at 100 mg/L and 500 mg/L (test substance) was performed.
The sludge respiration test is a modified ISO standard procedure (ISO/8192).
The results from the modified sludge inhibition test showed that the inhibition of the sludge was less than 10% for the test substance at 100 mg/L and 500 mg/L.
The test material in the Zahn-Wellen test was according to the results applied in a concentration of approximately 100 mg carbon/L.

Key result

Parameter:

% degradation (DOC removal)

Value:

55

Sampling time:

34 d

Details on results:

Within the first 20 days there is no difference between the abiotic and biotic degradation indicating a lag phase of approximately 20 days and a slight abiotic degradation for the test substance. The abiotic degradation is responsible for degradation of about 20% of the initial concentration within 28 days.

Results with reference substance:

The reference substance was degradedwas degraded to 90% within 14 days. The observed degradation of Diethylenglycol shows satisfying microbial activity in the sludge.

Validity criteria for the measurement of the biodegradation according to OECD 302 B:

Target condition according to guideline:	Actual condition according to the study:	Validity criteria met:
The physico-chemical adsorption can, in some cases, play a role and this is indicated when there is complete or substantial removal in the first 3h and the difference between blanks and test solutions remains at an unexpected low value. In such cases additional information is obtained from a comparison between the 3h value, the expected initial value calculated from the amount of test substance added and the value measured before the inoculum is added.	There was no significant adsorption of the test substance to the sludge or glass vessel as there is only a slight difference between samples taken at start and at 3 hours.	Yes
The test is considered valid if the procedural control shows the removal of the reference compound by at least 70% within 14 d and if the removal of DOC (or COD) in the test suspension took place relatively gradually over days or weeks, since this indicates biodegradation.	Diethylenglycolwas used as a reference compound. There was 90% degradation of the reference substance within 14 d.	Yes
Before starting the test, make certain with appropriate methods that no inhibition of sludge occurs at the chosen concentration of test substance if this is not already known. If an inhibitory effect is found, reduce the concentration of test substance to a level which is unlikely to be inhibitory.	To avoid an inhibitory effect of the test substance on the sludge a modified sludge respiration test at 100 mg/l aner 500 mg/L was performed (ISO/8192). According to results of this test the concentration of 100 mg/L carbon of the test compounds was chosen.	Yes

Validity criteria fulfilled:

yes

Remarks:

See 'Any other information on results incl. tables'.

Interpretation of results:

inherently biodegradable

Conclusions:

The prolongation of the test period showed that approximately 55% of the initial concentration is degraded after 34 days. The results showed that the test substance after a lag period of about 20 days is biodegradable.

Executive summary:

The study was performed to assess the inherent biodegradability of the test substance. The study was conducted in accordance with OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test). The test was performed at a final concentration of the test substance of 104 mg/L DOC in a mineral medium inoculated with activated sludge (domestic) and incubated over a prolonged period of 34 days. During this period the biodegradation is followed by analysis of dissolved organic carbon (DOC). Within the first 20 days there is no difference between the abiotic and biotic degradation indicating a slight abiotic degradation that is responsible for degradation of about 20% of the initial concentration of the test substance. Due to the initiation of the biodegradation within 28 days, the test period was prolonged to 34 days. The test substance showed 55% degradation after 34 days. The results showed that the test substance after a lag period of about 20 days is biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Jan - Feb 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

Version / remarks:

adapted 1981

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: The activated sewage sludge was collected from a municipal sewage treatment plant, predominantly dealing with domestic sewage.
- Storage conditions: During the time between collection and use the sewage sludge was kept under aerobic conditions
- Storage length: 1 day
- Preparation of inoculum for exposure: The inoculum was obtained from the supernatant.

Duration of test (contact time):

28 d

Initial conc.:

22.5 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: According to guideline
- Test temperature: 20-25°C
- pH: 7.2
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: Incubation on a shaker
- Number of culture flasks/concentration: 2 replicates
- Method used to create aerobic conditions: Aeriation
- Measuring equipment: Carbon analyzer for the determination of total organic carbon (TOC) and dissolved organic carbon (DOC)

SAMPLING
- Sampling frequency: Sampies from the test solutions for all analyses were taken on days 0, 1, 4, 7, 14, 21, 27 and 28.
- Sampling method: 10 mL of each solution were filtrated and analyzed

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes
- Abiotic sterile control: No
- Toxicity control: No

Reference substance:

acetic acid, sodium salt

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

0 d

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

1 d

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

4 d

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

7 d

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

14 d

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

21 d

Parameter:

% degradation (DOC removal)

Value:

2

Sampling time:

27 d

Key result

Parameter:

% degradation (DOC removal)

Value:

1

Sampling time:

28 d

Results with reference substance:

The reference substance sodium acetate was degraded to 90% after 4 days.

Validity criteria for the measurement of the biodegradation according to OECD 301:

Target condition according to guideline:	Actual condition according to the study:	Validity criteria met:
In order to check the procedure, reference compounds which meet the criteria for ready biodegradability are tested by setting up an appropriate vessel in parallel as part of normal test runs. Suitable compounds are aniline (freshly distilled), sodium acetate and sodium benzoate.	Sodium acetate was used as a reference compound.	Yes
A test is considered valid if the difference of extremes of replicate values of the removal of the test chemical at the plateau, at the end of the test or at the end of the 10-d window, as appropriate, is less than 20% and if the percentage degradation of the reference compound has reached the pass levels by day 14.	The difference between the two measured values of the test substance at the end of the test (28 d) was <5% There was 90% degradation of the reference substance after 14 d - the pass level (70 % for DOC) was reached.	Yes

Validity criteria fulfilled:

yes

Remarks:

See 'Any other information on results incl. tables'.

Interpretation of results:

not readily biodegradable

Conclusions:

The test substance showed 1% degradation after 28 days. Therefore, the test substance is considered to be ''Not Readily Biodegradable'.

Executive summary:

The study was performed to assess the ready biodegradability of the test substance. The study was conducted in accordance with OECD 301 on ready biodegradability: Modified OECD Screening Test, No. 301 E. The test was performed at a final concentration of the test substance of 20 mg/L DOC in a mineral medium for 28 days under aerobic conditions in the dark. The medium was inoculated with activated sewage sludge (predominantly domestic). During this period the biodegradation was followed by analysis of dissolved organic carbon (DOC). The test substance showed 1% biological degradation after 28 days. Therefore, the test substance is considered to be 'Not Readily Biodegradable'.

Description of key information

According to OECD 301 E the test substance is considered to be 'Not Readily Biodegradable'. A further test on inherent biodegradabiltiy according to OECD 302 B showed that the test substance was to 55% degraded after 34 days. The results showed that the test substance after a lag period of about 20 days is biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable

Type of water:

freshwater

Additional information

A study was performed to assess the ready biodegradability of the test substance. The study was conducted in accordance with OECD 301 on ready biodegradability: Modified OECD Screening Test, No. 301 E. The test was performed at a final concentration of the test substance of 20 mg/L DOC in a mineral medium for 28 days under aerobic conditions in the dark. The medium was inoculated with activated sewage sludge (predominantly domestic). During this period the biodegradation was followed by analysis of dissolved organic carbon (DOC). The test substance showed 1% biological degradation after 28 days. Therefore, the test substance is considered to be 'Not Readily Biodegradable'. In accordance with the OECD guideline 301 E, the test substance is not readily biodegradable under the conditions of the test. This does not necessarily mean that the test substance is not biodegradable and a further tests have been carried out in order to evaluate the inherent biodegradability of the test substance. The study on inherent biodegradability of the test substance was conducted in accordance with OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test). The test was performed at a final concentration of the test substance of 104 mg/L DOC in a mineral medium inoculated with activated sludge (domestic) and incubated over a prolonged period of 34 days. During this period the biodegradation is followed by analysis of dissolved organic carbon (DOC). Within the first 20 days there is no difference between the abiotic and biotic degradation indicating a slight abiotic degradation that is responsible for degradation of about 20% of the initial concentration of the test substance. Due to the initiation of the biodegradation within 28 days, the test period was prolonged to 34 days. The test substance showed 55% degradation after 34 days. The results showed that the test substance after a lag period of about 20 days is biodegradable.