1-benzhydrylpiperazine

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:

2016-02-09 to 2016-03-31

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

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
- Source and lot/batch No.of test material: M15BB1451
- Expiration date of the lot/batch: 2021-01-30
- Purity test date: 2015-05-21 (certificate of analysis release date)

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature
- Stability under test conditions: no data

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source: municipal sewage treatment plant receiving predominantly domestic sewage, 'Waterschap Aa en Maas', 's-Hertogenbosch, The Netherlands.
- Storage conditions: Sludge was kept under continuous aeration until further treatment.
- Preparation of inoculum for exposure: sludge was kept under continuous aeration until further treatment. Before use, the sludge was allowed to settle (54 minutes) and the supernatant liquid was used as inoculum.
- Concentration of sludge: The concentration of suspended solids was determined to be 3.5 g/L in the concentrated sludge.
- 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.:

15 mg/L

Based on:

test mat.

Initial conc.:

12 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: weighed amounts were added to the 2-litre test bottles containing medium with microbial organisms and mineral components:
* test item bottle A: 29.96 mg;
* test item bottle B: 29.98 mg;
* toxicity control bottle: 29.91 mg. To this end, 10 mL of Milli-RO water was added to each weighing bottle containing the test item. After vigorous mixing (vortex) the resulting suspension was added quantitatively to the test medium. The test solutions were continuously stirred during the test, to ensure optimal contact between the test item and the test organisms.
- Additional substrate: no
- Test temperature: 21.9-22.8°C
- pH: 7.4-7.8, measured prior to testing in each test flask before addition of inoculum, and again in each test flask at the end of the incubation period
- pH adjusted: no
- Aeration of dilution water: The test solutions were continuously stirred and aerated during the test.
- Continuous darkness: yes

TEST SYSTEM
- Test flasks: 2 L glass brown coloured bottles
- Number of culture flasks/concentration: 2
- 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).
- Details of trap for CO2 and volatile organics if used: 3 CO2-absorbers (bottles filled with 100 mL 0,0125 M Ba(OH)2) were connected in series to the exit air line of each bottle. The CO2 produced in each test bottle reacted with the barium hydroxide in the gas scrubbing bottle and precipitated out as barium carbonate. The amount of CO2 produced was determined by titrating the remaining ba(OH)2 with 0,05 M standardized HCl.

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

Test performance:

In the toxicity control, less than 25% biodegradation occurred within 14 days (10%, based on ThCO2). Therefore, the test item was found to have a possible small inhibiting effect on microbial activity.
This inhibiting effect was not observed in the first invalid test. In the invalid test the positive control, test item and toxicity control showed 55%, 1% and 0%(in test bottle A and B respectively) and 39% biodegradation within 14 days, respectively.
A possible small inhibiting effect of JNJ-130806-AAA (T000750) on microbial activity was considered to have had no effect on the outcome of this study (the criterion for ready biodegradability).

Parameter:

% degradation (CO2 evolution)

Value:

< 25

Sampling time:

14 d

Details on results:

JNJ-130806-AAA (T000750) was designated as not readily biodegradable, as the pass level for ready biodegradability, i.e. biodegradation of at least 60% in a 10-day window within the 28-day period of the test was not reached.

Results with reference substance:

The positive control item was biodegraded by at least 60% (70%) within 14 days, confirming suitability of the activated sludge.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

A 28-d ready biodegradability test (OECD 301B, modified sturm test) using unadapted activated sludge from a predominantly domestic waste water treatment plant indicated that JNJ-130806-AAA (T000750) was not readily biodegradable under the conditions of the test (initial concentration 15 mg/L corresponding to 12 mg TOC/L). The test substance showed only 1% and 3% in bottle A and B respectively, based on ThCO2). The test substance did not inhibit microbial activity at the concentration used in the test. The results of the test can be considered reliable without restriction.

Description of key information

A 28-d ready biodegradability test (OECD 301B, modified sturm test) using unadapted activated sludge from a predominantly domestic waste water treatment plant indicated that JNJ-130806-AAA (T000750) was not readily biodegradable under the conditions of the test (initial concentration 15 mg/L corresponding to 12 mg TOC/L). The results of the test can be considered reliable without restriction.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed