N-phenyl-N-piperidin-4-ylpropionamide

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-07-04 to 2015-08-04

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: ISO International Standard 10634 "Water Quality - Guidance for the preparation and treatment of poorly water-soluble organic compounds for the subsequent evaluation of their biodegradability in an aqueous medium"

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

N-phenyl-N-piperidin-4-ylpropionamide

EC Number:

216-543-3

EC Name:

N-phenyl-N-piperidin-4-ylpropionamide

Cas Number:

1609-66-1

Molecular formula:

C14H20N2O

IUPAC Name:

N-phenyl-N-piperidin-4-ylpropionamide

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study reports): JNJ-1594255-AAA (T000425)
- Physical state: solid (powder)
- Appearance: white

Specific details on test material used for the study:

- Physical state: solid
- Analytical purity: 100%
- Lot/batch No.: 00454795
- Expiration date of the lot/batch: 2006-12-09
- Stability under test conditions: stable under storage conditions
- Storage condition of test material: at room temperature (range of 20 ± 5 deg C), light protected

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

12 mg/L

Based on:

TOC

Initial test substance concentration 2

Initial conc.:

17 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: test water prepared according to test guidelines, analytical grade salts dissolved in tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon.
* 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
The test item was directly weighed into the test flasks, Milli-RO water added, vigorous mixing (vortex). The resulting suspension was added quantitatively to the test medium.
- Additional substrate: no
- Test temperature: 21.4-22.9°C
- pH: 7.5-7.6 (measured prior to testing in each test flask before addition of inoculum) and 7.6-8.0 (in each test flask at the end of the incubation period)
- pH adjusted: no
- Aeration of dilution water: yes
- 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 botle 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
- test substance and inoculum: 2 replicates
- Inoculum blank: two replicates
- Toxicity control: one replicate
- Procedure control: 1 replicate

SAMPLING
- Sampling frequency: every second or third day during the first 10 days, and thereafter at least every fifth day until the 28th day
- 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.

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

> 7 - < 10

Sampling time:

29 d

Details on results:

No significant biodegradation of the test item occurred within 28 days of incubation (7 and 10% in bottle A and B resp.). The toxicity controls indicated that the test item did not have an inhibitory effect on the microbial activity.

BOD5 / COD results

Results with reference substance:

The positive control item was biodegraded by at least 60% (73%) within 14 days, confirming suitability of the activated sludge.

Applicant's summary and conclusion

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-1594255-AAA (T000425) was not readily biodegradable under the conditions of the test (initial concentration 17 mg/L). The results of the test can be considered reliable without restriction.