2-Pyridinecarboxamide, 4-(4-aminophenoxy)-N-methyl-

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:

6/2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Type: mixed population of aquatic microorganisms (activated sludge)
Origin: aeration tank of a waste water plant treating predominantly domestic sewage (Wupper area water authority)
Date of collection: 2004-05-03
Pretreatment: none
Concentration of inoculum: 30 mg/L ss

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Pretreatment of the test substance:
25 mg test substance were weighed out on aluminium foil. This substance inclusive the aluminium foil was added to the test vessels to give a test concentration of 100 mg/L test substance.
Exposure conditions:
Test volume : 250 ml
Test apparatus : Voith Sapromat
Mixing: 1 magnetic stirrer per test vessel
Incubation temperature : 22 +- 2°C

Chemical analysis of NO3(-n)/ NO2 (-n):
Method: determination of nitrite nitrogen and nitrate nitrogen and the sum of both by flow analysis (CFA and FIA) and spectrometric datection
test apparatus: continuous flow analyser SKALAR SAN Plus System

Reference substance:

benzoic acid, sodium salt

Remarks:

purity: 99%, batch no.: 31345-032 (Sigrna-Aldrich)

Parameter:

% degradation (O2 consumption)

Value:

1

Sampling time:

28 d

Details on results:

- The BOD values of the test item after 28 days were corrected for the oxygen consumed by nitrification.
- The used concentrations of the test item did not show toxic effects to bacteria
- pH of test vessel: 7.7 (mean value)

Results with reference substance:

Kinetic of reference substance ( % Degr.):
78 after 8 days
85 after 14 days
89 after 20 days
89 after 28 days

After 28 days the pH values of the flasks containing test item was 7.7

Validity criteria fulfilled:

yes

Remarks:

(-Ready biodegradability of reference comp. >60% 14d. -No toxicity in control. -Replicates difference< 20% . - Oxygen uptake of blank inoculum=< 60mg/l. -No pH influence.)

Interpretation of results:

not readily biodegradable

Conclusions:

Within 28 days, a degradation rate of 1 % was determined. The test item is considered to be "Not Readily Biodegradable". The reference compound sodium benzoate showed 85 % degradation after 14 days.

Executive summary:

To test for its biodegradability potential, the substance was incubated for 28 days in continuously stirred 250 ml closed flask (in duplicate) in the dark with an inoculum originally collected from a local, predominantly domestic sewage treatment plant. In this assay, biodegradation was estimated by biological oxygen demand (BOD) over time. BOD was measured daily by a manometer. The incubation temperature was 22 ± 2°C, pH was 7.7(test item). The concentration of innoculum was 30 mg /L suspended solids and the one of the substance was 100 mg/L. An endogenous control and a toxicity control run in parallel. The BOD values of the test item after 28 days were corrected for the oxygen consumed by nitrification. The used concentrations of the test item did not show toxic effects to bacteria.

 

The 28-day degradation was 1% according to the OECD method 301F. In conclusion the substance is not readily biodegradable.

Description of key information

Within 28 days, a degradation rate of 1 % was determined. The test item is considered to be "Not Readily Biodegradable". The reference compound sodium benzoate showed 85 % degradation after 14 days.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater