Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

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:
15 February 2019 (Experimental start) to 15 March 2019 (Experimental Completion)
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)
Deviations:
no
GLP compliance:
yes
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source of test material: Materia Inc.
- Lot/batch No.of test material: RP229-0714
- Expiration date of the lot/batch: 26 November 2019
- Purity test date: 26 November 2018

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Ambient (15ºC ± 10ºC), no protection from light
- Stability under test conditions: Assumed stable for the duration of the study
- Solubility and stability of the test substance in the solvent/vehicle: 0.00538g/Liter at 20°C, stable.
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: None

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: The solubility of the test material was stated to be 0.00538g/Litre at 20°C and a surfactant was therefore used to emulsify the sample. To prepare the emulsion, 0.5007g of Tricylopentadiene (Distilled) was intimately mixed with 0.2502g of non-ionic surfactant (IGEPAL CA 630). The emulsion was gradually diluted by the addition of deionised water and then made up to volume (500ml) to give a concentration of 1.0014g/L.

FORM AS APPLIED IN THE TEST (if different from that of starting material) The solubility of the test material was stated to be 0.00538g/Litre at 20°C and a surfactant was therefore used to emulsify the sample. To prepare the emulsion, 0.5007g of Tricylopentadiene (Distilled) was intimately mixed with 0.2502g of non-ionic surfactant (IGEPAL CA 630). The emulsion was gradually diluted by the addition of deionised water and then made up to volume (500ml) to give a concentration of 1.0014g/L.

OTHER SPECIFICS:
- measurement of pH, osmolality, and precipitate in the culture medium to which the test chemical is added: Not specified
Oxygen conditions:
aerobic
Inoculum or test system:
sewage, predominantly domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): The inoculum used for this test was the secondary effluent from a predominantly domestic sewage treatment works.

Inoculum source: Cambridge STW, Cowley Road, Cambridge
Date of collection: 14 Feb 2019
Pre-treatment: Filtered (Whatman No. 54)
Temperature at start of test: 20.7°C
Concentration of inoculum: 1ml/L
Duration of test (contact time):
28 d
Initial conc.:
1.001 g/L
Based on:
formulation
Remarks:
test item / emulsifing agent / deionised water
Parameter followed for biodegradation estimation:
DOC removal
Details on study design:
TEST CONDITIONS
- Composition of medium:
- Mineral medium: The dilution water was prepared by adding secondary effluent inoculum and mineral nutrient stock solutions to deionised water, aerating it strongly for 20 minutes, letting it stand for 22 hours then adding secondary effluent inoculum.

Nutrient stock and mineral media preparation
Buffer Required concentration in stock solution Actual concentration in Stock Solution (±5%) Concentration in test medium (±5%)
Phosphate g/L g/L mg/L
KH2PO4 8.50 8.50 8.50
K2HPO4 21.75 21.75 21.75
Na2HPO4.7H2O 50.30 50.30 50.30
Ammonium chloride 0.50 0.50 0.50

Magnesium g/L g/L g/L
MgSO4.7H2O 22.50 22.50 22.50

Calcium g/L g/L g/L
CaCl2.2H2O 36.40 36.40 36.40

Iron (III) chloride g/L g/L g/L
FeCl3 0.15 0.15 0.15
All buffer stocks were prepared using deionised Ecotox Maxima grade water, the phosphate, magnesium and calcium buffers were made in advance and stored at 4ºC±2ºC, the Iron (III) chloride buffer was made on day of use and was not stored.
All buffer solutions were added at 1ml/L to a total volume of 40L of deionised water.
Secondary effluent was added at 1ml/L to a total volume of 3.5L of deionised water.

- Additional substrate: None
- Solubilising agent (type and concentration if used): The emulsifying agent was non-ionic surfactant (IGEPAL CA 630). To prepare the emulsion, 0.5007g of Tricylopentadiene (Distilled) was intimately mixed with 0.2502g of non-ionic surfactant (IGEPAL CA 630). The emulsion was gradually diluted by the addition of deionised water and then made up to volume (500ml) to give a concentration of 1.0014g/L.
- Test temperature: The bottles are incubated in the dark at 22 ±2ºC
- pH: Not specified
- pH adjusted: no
- Aeration of dilution water: The dilution water was prepared by adding secondary effluent inoculum and mineral nutrient stock solutions to deionised water, aerating it strongly for 20 minutes (using an air pump and air stone that is placed in the media) the day before the test. The media is then left to settle/stand for 22 hours before the addition of the secondary effluent inoculum and the initiation of the test.
- Continuous darkness: yes


TEST SYSTEM
- Culturing apparatus: 250ml BOD bottles filled to absolute volume with the test material dissolved in the test medium and sealed with a glass stopper
- Number of culture flasks/concentration: 1 replicate (Control), 2 replicates (TCPD at 1.0014g/L on days 7 & 14) 3 replicates (TCPD at 1.0014g/L.on days 21 & 28)
- Method used to create aerobic conditions: Not specified
- Measuring equipment: Dissolved oxygen (DO) concentrations were measured using a dissolved oxygen meter
- Test performed in closed vessels due to significant volatility of test substance: No, test item, non-volatile
- Test performed in open system: No

SAMPLING: No sampling

CONTROL AND BLANK SYSTEM
- Inoculum blank: To account for any degradation of the surfactant in test vessels, a series of surfactant control bottles were prepared by addition of the surfactant stock to inoculated mineral medium (1ml/L) to give a final concentration of 1.0mg/L, representing the final concentration of the surfactant in test sample bottles. These were used as the blank values for the test material.
- Abiotic sterile control: No
- Toxicity control: No

STATISTICAL METHODS: None specified
Reference substance:
other: Sodium acetate tested at 5.02 mg/L.
Test performance:
Tricylopentadiene (Distilled) is not readily biodegradable under the conditions of this test. The test item failed to meet the requirements for a pass in this test (≥60% degradation relative to the ThOD value) as a maximum of -5% was recorded on day 7.

The solubility of Tricylopentadiene (Distilled) was stated to be 0.00538g/Litre at 20°C. A surfactant (IGEPAL CA 360) was used to emulsify the sample. The effects of surfactant degradation were taken into account when calculating the degradation of the test material.

The guideline requires that the reference material (Sodium acetate at 5.02mg/L.) degrades by at least 60% of its ThOD, and that the blank dissolved oxygen loss does not exceed 1.5mg/L after 28 days. Both these criteria were satisfied for this test; a maximum value of 82% degradation of sodium acetate was achieved on day 21, and the blank DO loss was 1.44mg/L recorded on day 28. In addition, the residual DO values should not fall below 0.5mg/L in the test vessels, a minimum value of 6.74mg/L was recorded on day 28 and satisfies this validity criterion.



Key result
Parameter:
% degradation (DOC removal)
Value:
-11
Sampling time:
28 d
Remarks on result:
other:
Remarks:
Not readily biodegradable (highest value was -5 on day 7)

Degradation: The calculated percent degradation values for Tricylopentadiene (Distilled) and reference material are given below:

                              Incubation period (days)
      7     14        21        28
 Replicate number  1  2 1  2  1 1
 Tricylopentadiene (Distilled) (%)  -6 -5  -14  -14  -7 -9  -10   -13 -15  -7 
 Average degradation (%)     -5     -14        -9        -11
 Reference material (%)  68 75  74  78  85  86  75  80  78  79 
 Average degradation (%)       72     76      82          79

  ThOD of sodium acetate 780mgO2/g.

Validity criteria fulfilled:
yes
Interpretation of results:
not readily biodegradable
Conclusions:
Tricylopentadiene (Distilled) is not readily biodegradable under the conditions of this test.

Description of key information

Tricylopentadiene (Distilled) is not readily biodegradable under the conditions of this test.

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed
Type of water:
freshwater

Additional information