Diallyl hexahydrophthalate

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:

13 December 2016 - 21 August 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Source: The sponsor. Lot/batch number: 40201
- Expiration date of the lot/batch: 26 January 2019
- Purity test date: 99.2%

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity: n/a
- Specific activity: n/a
- Locations of the label: n/a
- Expiration date of radiochemical substance: n/a

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Controlled room temperature (15-25°C, below 70 RH%), protected from light
- Stability under test conditions: not specified
- Solubility and stability of the test substance in the solvent/vehicle: not specified
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: not specified

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: The respective amount of MDAC was weighed in directly to reach the required test item concentration of 2.8 mg/L.
- Preliminary purification step (if any): n/a
- Final dilution of a dissolved solid, stock liquid or gel: 2.8 mg/L test item concentration
- Final preparation of a solid: n/a

FORM AS APPLIED IN THE TEST (if different from that of starting material) n/a

OTHER SPECIFICS: n/a

Oxygen conditions:

aerobic

Inoculum or test system:

other: secondary effluent from a domestic waste water treatment plant

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Secondary effluent, microorganisms from a domestic waste water treatment plant. The secondary effluent was supplied from the sewage plant for domestic sewage in Veszprém, Hungary. No other information was supplied in the report.
- Laboratory culture: not specified
- Method of cultivation: not specified
- Storage conditions: The secondary effluent used for this study was allowed to settle approximately for an hour, then the decanted effluent was aerated until use (not later than an hour).
- Storage length: The secondary effluent used for this study was allowed to settle approximately for an hour, then the decanted effluent was aerated until use (not later than an hour).
- Preparation of inoculum for exposure: not specified
- Pretreatment: not specified
- Concentration of sludge: n/a
- Initial cell/biomass concentration: not specified
- Water filtered: yes/no not specified
- Type and size of filter used, if any: not specified

Duration of test (contact time):

ca. 28 d

Initial conc.:

ca. 2.8 mg/L

Based on:

ThOD

Remarks:

ThOD of 2.16 mg O2/mg test item

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: Made up of 4 stock solutions (a-d). Composition if each stock solutioin is detailed below:
a) KH2PO4 2.125 g, K2HPO4 5.4375 g, Na2HPO4 x 12H2O 16.795 g, NH4Cl 0.125 g, Deionised water ad 250 mL
b) MgSO4 x 7 H2O 5.625 g, Deionised water ad 250 mL
c) CaCl2 x 2 H2O 9.10 g, Deionised water ad 250 mL
d) FeCl3 x 6 H2O 0.25 g, Deionised water ad 1000 mL
Test medium was aerated for 20 minutes and allowed to stand for 20 hours at the test temperature.

- Additional substrate: n/a
- Solubilising agent (type and concentration if used): deionised water
- Test temperature: 22 +/-2 °C
- pH: 7.39
- pH adjusted: no
- CEC (meq/100 g):
- Aeration of dilution water: not specified
- Suspended solids concentration: not specified
- Continuous darkness: yes (The test flasks were placed into an incubator and kept at 21.5 - 22.9°C, in the dark).
- Other: n/a

TEST SYSTEM
- Culturing apparatus: BOD bottles (300 mL) with special neck and glass stoppers.
- Number of culture flasks/concentration: There were 10 bottles per test, divided into a) and b), each containing 5 bottles. Only one test item concentrated was tested; 2.8 mg/L. There were two replicates of test item (1a and 1b), 5 bottles in each. There were two replicates for the reference item (2a and 2b), and two replicates for the toxicity control (2.8 mg/L test item plus 3.6 mg/L reference item) (3a and 3b).
- Method used to create aerobic conditions: n/a
- Method used to create anaerobic conditions: Test flasks were tightly closed with glass stoppers
- Measuring equipment: Oxygen meter - a stirring O2 electrode
- Test performed in closed vessels due to significant volatility of test substance: Test was perfomed in sealed test flasks to prevent additional oxygen from entering the system
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used: n/a
- Other:

SAMPLING
- Sampling frequency: no samples were taken. Oxygen levels within the flasks were measured in duplicate on days 0, 7, 14, 21 and 28.
- Sampling method: n/a
- Sterility check if applicable: No sterilty check was undertaken, but test flasks were cleaned prior to use: BOD flasks was cleaned with 5 - 10 mL of a wash liquid (2.5 g iodine and 12.5 g potassium iodide per litre of 1 % w/v sulphuric acid) by shaking well to coat the bottle walls. After allowing to stand for 15 minutes, the wash liquid was poured off, and the bottles were thoroughly rinsed with tap water and deionised water.
- Sample storage before analysis: n/a
- Other: n/a

CONTROL AND BLANK SYSTEM
- Inoculum blank: Inoculum control took place in flasks 3a and 3b, where only filtered inoculum was added to 3.38 litres of aqueous test medium.
- Abiotic sterile control: Procedure control took place in flasks 2a and 2b. Based on the theoretical oxygen demand (ThOD) of Sodium benzoate (1.67 mg O2 per mg), stock solution corresponding to 12.168 mg of Sodium benzoate was mixed into 3.38 litres of aqueous test medium (corresponding to 3.6 mg/L reference item, respectively a ThOD of about 6.012 mg O2/L).
- Toxicity control: Toxicity control took place in flasks 4a and 4b, where the test item (9.5 mg) and the reference item stock solution* (34.0 mL) were mixed into 3.40 litres of aqueous test medium corresponding to 2.8 mg/L test item (ThOD of 6.048 mg O2/L) and 3.6 mg/L reference item (ThOD of 6.012 mg O2/L).
- Other:

STATISTICAL METHODS:

Reference substance:

other: Sodium benzoate

Remarks:

Batch number: MKBP4737V, expiry date: June 2017

Preliminary study:

n/a

Test performance:

The study met the validity criteria.

Key result

Parameter:

other: % biodegredation

Value:

ca. 1.7

Sampling time:

28 d

Remarks on result:

other: Test item MDAC is considered not readily biodegradable, can be assumed to be not inhibitory at the applied concentration level of 2.8 mg/L on the secondary effluent microorganisms

Details on results:

Under the test conditions the percentage biodegradation of MDAC reached a mean of 1.7 % after 28 days based on the ThOD of the test item. According to the test guidelines the pass level for ready biodegradability is removal of 60 % ThOD. Therefore the test item is considered not readily biodegradable.

Results with reference substance:

% biodegredation with reference substance, the reference item Sodium benzoate was sufficiently degraded to a mean of 77.5 % after
14 days, and to a mean of 86.7 % after 28 days of incubation, based on ThOD, thus confirming the suitability of the used inoculum.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Under the test conditions the percentage biodegradation of MDAC reached a mean of 1.7 % after 28 days based on the ThOD of the test item. According to the test guidelines the pass level for ready biodegradability is removal of 60 % ThOD. Therefore the test item is considered not readily biodegradable.

According to the test guidelines the test item can be assumed to be not inhibitory at the applied concentration level of 2.8 mg/L on the secondary effluent microorganisms because degradation was >25 % within 14 days.

Executive summary:

The test item MDAC was investigated for its ready biodegradability in a Closed Bottle Test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. The test system was a microbial inoculum of good quality, collected from a sewage plant for domestic sewage. The sludge was allowed to settle and then aerated until use

Under the test conditions the percentage biodegradation of MDAC reached a mean of 1.7 % after 28 days based on the ThOD of the test item. According to the test guidelines the pass level for ready biodegradability is removal of 60 % ThOD. Therefore the test item is considered not readily biodegradable. According to the test guidelines the test item can be assumed to be not inhibitory at the applied concentration level of 2.8 mg/L on the secondary effluent microorganisms because degradation was >25 % within 14 days.

Description of key information

This substance is considered to be not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater