cis-2-(2,4-dichlorophenyl)-2-(1H-imidazol-1-ylmethyl)-1,3-dioxolane-4-ylmethyl methanesulphonate monohydrochloride

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:

10 June 2015 - 09 July 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Scientifically acceptable study performed according to OECD 301B test guidelines and under GLP conditions. On day 14 it was observed that none of the vessels were aerated because the gas cylinder was empty. A short disruption (< 1 day) does not influence the micro-organisms. The study integrity was therefore not adversely affected by the deviation.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO DIS 9439 (Ultimate Aerobic Biodegradability - Method by Analysis of Released Carbon Dioxide)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Identification JNJ-17336007-AAC (T001202)
- Appearance White powder (determined by WIL Research Europe at receipt of the test item)
- Batch I14KB4717
- Purity/Composition See Certificate of Analysis in appendix

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Test item storage conditions At room temperature
- Stable under storage conditions until 25 November 2016 (retest date)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Municipal sewage treatment plant: 'Waterschap Aa en Maas', 's-Hertogenbosch, The Netherlands, receiving predominantly domestic sewage.
- Storage conditions: sludge was kept under continuous aeration until further treatment
- Preparation of inoculum for exposure: Before use, the sludge was allowed to settle (75 minutes). The supernatant liquid was used as inoculum at the amount of 10 ml/L of mineral medium. The day before the start of the test (day -1) mineral components, Milli-RO water (ca. 80% of final volume) and inoculum (1% of final volume) were added to each bottle. This mixture was aerated with synthetic air overnight to purge the system of CO2
- Pretreatment: no
- Concentration of sludge: concentration of suspended solids of concentrated sludge was determined to be 4.6 g/L
- Water filtered: Tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon.

Duration of test (contact time):

28 d

Initial conc.:

29.5 mg/L

Based on:

test mat.

Initial conc.:

12 mg/L

Based on:

other: TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: OECD standard medium
* mineral stock solution A: 8.5 g KH2PO4, 21.75 g K2HPO4, 67.20 g Na2HPO4.12H2O, 0.5 gNH4Cl dissolved in 1 L Milli-Q water, pH 7.4 ± 0.2
* mineral stock solution B: 22.50 g MgSO4.7H2O dissolved in 1 L Milli-Q water
* mineral stock solution C: 36.4 g CaCl2.2H2O dissolved in 1 L Milli-Q water
* mineral stock solution D: 0.25 g FeCl3.6H2O dissolved in 1 L Milli-Q water
* Final test medium: 10 mL of solution A and 1 mL of solutions B, C and D per L of test medium
- Additional substrate: no
- Solubilising agent (type and concentration if used): no
- Test temperature: between 22.0 and 23.5°C
- pH: Inoculum blank: start: 7.6, on day 28: 7.6; test substance: start: 7.5-7.6, on day 28: 7.5-7.6
- pH adjusted: no
- Aeration of dilution water: yes
- Suspended solids concentration (initial): not reported
- Continuous darkness: yes, test media were excluded from light.

TEST SYSTEM
- Culturing apparatus: 2 litre glass brown coloured bottles
- Number of culture flasks/concentration: 2
*Test suspension: containing test item and inoculum (2 bottles)
*Inoculum blank: containing only inoculum (2 bottles)
*Positive control: containing reference substance and inoculum (1 bottle)
*Toxicity control: containing test item, reference substance and inoculum (1 bottle)
- Method used to create aerobic conditions: A mixture of oxygen (~20%) and nitrogen (~80%) was passed through a bottle, containing 0,5 - 1 L 0,0125 M Ba(OH)2 solution to trap CO2. The synthetic air was sparged through the scrubbing solutions at a rate of ~1-2 bubbles per second ( ~30-100 mL/min). The initial suspension of unspiked test medium and inoculum was aerated with this CO2-free air overnight to purge the system of CO2 prior to testing. This CO2-free air was also used for aeration during the test.
- Measuring equipment: CO2-evolution was determined through titration of the remaining Ba(OH)2 with 0.05 M standardized HCl.
- Details of trap for CO2 and volatile organics if used: Three CO2-absorbers (bottles filled with 100 mL 0.0125 M Ba(OH)2 were connected in series to the exit air line of each test bottle.

SAMPLING
- Sampling frequency: every 2nd or 3rd day during the first 10 days, and thereafter at least every 5th day until day 28, for the inoculum blank and test suspension. Titrations for the positive and toxicity control were made over a period of at least 14 days.
- Sampling method: the absorber bottle closest to the incubation system was sampled each time, the second and third bottle were moved one position closer to the system and a new bottle was added at the end
- On the 28th day, pH of test suspensions was measured and 1 mL of concentrated HCl was added to each bottle. Bottles were aerated overnight to drive off CO2 present in the test suspension. The final titration was made on day 29.

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, two replicates with only inoculum
- Toxicity control: yes, one replicate with test item, reference substance, and inoculum
- Procedure control: yes, 1 replicate with reference item and inoculum

Reference substance:

acetic acid, sodium salt

Parameter:

% degradation (CO2 evolution)

Value:

4

Sampling time:

28 d

Remarks on result:

other: Bottle A

Parameter:

% degradation (CO2 evolution)

Value:

11

Sampling time:

28 d

Remarks on result:

other: Bottle B

Details on results:

In the toxicity control, more than 25% biodegradation occurred within 14 days (31%, based on ThCO2 of the test and positive control substances combined). Therefore, the test item was assumed not to inhibit microbial activity

Results with reference substance:

The positive control substance was biodegraded by at least 60% (73%) within 14 days.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

In this 28-day CO2 evolution test (modified Sturm test) using microorganisms from domestic non-adapted sludge, the test substance showed to be not readily biodegradable. The relative biodegradation values calculated from the measurements performed during the test period were 4% and 11% (based on ThCO2). In the toxicity control, JNJ-17336007-AAC (T001202) was found not to inhibit microbial activity. Since all criteria for acceptability of the test were met, this study was considered to be valid.

In conclusion, JNJ-17336007-AAC (T001202) was designated as not readily biodegradable

Description of key information

One study (Soeter, 2015) is included in this dossier and regarded as a key study (Klimisch score of 1).  The biodegradability of T001202 was determined according to OECD Guideline 301B and EU Method C.4 -C. Under the conditions of the test, T001202 was determined to be not biodegradable within 28 days.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The ready biodegradability of T001202 over 28 days was determined in a carbon dioxide (CO2) evolution test (modified Sturm test) (Soeter, 2015). The test item was tested in duplicate at 21 mg/L, corresponding to 12 mg TOC/L. The inoculum was unadapted activated sludge from a predominantly domestic waste water treatment plant. T001202 was found to be not readily biodegradable under the test conditions within the 28-d exposure period.