Reaction mass of (4Z,8E)-dodeca-4,8,11-trienal and (4E,8Z)-dodeca-4,8,11-trienal

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-11-13 - 2019-12-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Name cited in report: Dodecatrienal
- Source and lot/batch No.of test material: V15 Trienal-Dest. F.4-7+V16 Trienal-Dest.F4-8.
- Expiration date of the lot/batch: May 2020

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Storage at room temperature, avoid temperature >60 °C
- Stability under test conditions: stable

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Inoculum (activated sludge) was collected on 12th Nov. 2018 from the aeration tank of the wastewater treatment plant of Mannheim, Germany.
- Preparation of inoculum for exposure: A suitable aliquot of the activated sludge suspension was sieved by a finely woven mesh with a mesh size of about 1 mm. Subsequently, this sludge suspension was aerated for about 24 hours at 22 ±2° C with
carbon dioxide free air in order to reduce the inorganic carbon content in the blank controls. At the day of exposure, the aeration was stopped, and the sludge suspension was washed once using drinking water and was allowed to settle. After settling, the
supernatant was discarded. The remaining sludge suspension was filled up once more with drinking water and the final concentration of the sludge was adjusted to 6.0 g/L dry weight
- Pretreatment: none
- Concentration of sludge: Aliquots of 7.5 mL of this suspension were added to the 2 L test vessels containing 1.5 L test medium to obtain a final activated sludge concentration of 30 mg/L dry weight.

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: acccording to the guideline
- Solubilising agent (type and concentration if used): no
- Test temperature: 22 ±2 ° (Due to a technical malfunction, the test temperature was slightly below 20 °C (<0.25 °C) during the course of exposure)
- pH: 7.3 -7.4


TEST SYSTEM
- Culturing apparatus: 2L incubation bottles
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: aeration with carbon dioxide free air

- Measuring equipment: The TIC analyses were performed as repeat determination, using a TOC-analyzer
equipped with an auto sampler (Shimadzu TOC-5000A and/or TOC-L, or TOC
- Test performed in closed vessels due to significant volatility of test substance:
- Test performed in open system:
- Details of trap for CO2 and volatile organics if used: The bottles were then connected to two serial scrubbing bottles filled with 100 mL of 0.05 mol sodium hydroxide (NaOH) solution which act as the trap to capture the carbon dioxide evolved from the mineralization processes. Usually twice a week, the total inorganic carbon (TIC) values were measured from each test vessel. At each time point, NaOH solution from the CO2 capture trap that is directly connected to the incubation botte was used for the calculation of the produced carbon dioxide between two consecutive sampling points. When this first trap is removed from its position for sampling, the second trap was moved forward and connected directly to the test bottles. The emptied trap for TIC sampling was again filled with fresh sodium hydroxide solution and placed into the second position.


SAMPLING
- Sampling frequency: twice a week.
- Other: The samples for TICanalysis (absorption solution) were measured without further treatment

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2
- Toxicity control: 1

Reference substance:

aniline

Key result

Parameter:

% degradation (CO2 evolution)

Value:

92

Sampling time:

28 d

Results with reference substance:

Degree of biodegradation of the reference substance after 14 days: 84% CO2/ThCO2.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Dodecatrienal attained a maximum degree of biodegradation 92 ±7% CO2/ThCO2 (mean ±SD) after an exposure period of 28 days.
The degree of biodegradation at the end of the ten-day window was approximately 71 ±7% CO2/ThCO2 (mean ±SD).
Hence, the required pass level for ready biodegradability in accordance to the OECD Guideline 301B i.e., at least 60% of the theoretical CO2 production must be attained within 10 days of the degradation exceeding 10% within the 28-day period of the test was accomplished.
Dodecatrienal can therefore be evaluated as readily biodegradable in this carbon dioxide evolution test, based on the quantitative determination of the formed carbon dioxide in the test substance assays by comparison with the calculated maximal
theoretical carbon dioxide production.
The test substance has exhibited a high potential for degradation. Biodegradation of 92% CO2/ThCO2 with a ten-day window indicate that the test substance is ultimately biodegradable.

Description of key information

Dodecatrienal attained a maximum degree of biodegradation 92 ±7% CO2/ThCO2 (mean ±SD) after an exposure period of 28 days.

The degree of biodegradation at the end of the ten-day window was approximately 71 ±7% CO2/ThCO2 (mean ±SD).

Hence, the required pass level for ready biodegradability in accordance to the OECD Guideline 301B i.e., at least 60% of the theoretical CO2 production must be attained within 10 days of the degradation exceeding 10% within the 28-day period of the test was accomplished.

Dodecatrienal can therefore be evaluated as readily biodegradable in this carbon dioxide evolution test, based on the quantitative determination of the formed carbon dioxide in the test substance assays by comparison with the calculated maximal

theoretical carbon dioxide production.

The test substance has exhibited a high potential for degradation. Biodegradation of 92% CO2/ThCO2 with a ten-day window indicate that the test substance is ultimately biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable, fulfilling specific criteria

Type of water:

freshwater