1,3,5-Triazine-2,4-diamine, N2-[(1R,2S)-2,3-dihydro-2,6-dimethyl-1H-inden-1-yl]-6-(1-fluoroethyl)-

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:

2007-03-12 - 2007-05-21

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:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Ministerium für Umwelt und Naturschutz, Landwirtschaft und Verbraucherschutz des Landes Nordrhein-Westfalen, 40190 Düsseldorf, Germany

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Mixed population of aquatic microorganisms (activated sludge) from an aeration tank of a wastewater plant treating predominantly domestic sewage (Wupper area water authority, STP Odenthal)
- Storage conditions: After washing (see below) the inoculum was stored at room temperature under continuous shaking with aeration until use
- Storage length: max. 3 days
- Preparation of inoculum for exposure: Sludge was washed twice by adding mineral medium, centrifuging and decanting the supernatant
- Concentration of sludge: 30 mg/L ss
- Water filtered: no

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: According to Guideline
- Test temperature: 22 +/- 1 °C
- pH: after 28 days: 7.4 - 8.1
- pH adjusted: no
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes


TEST SYSTEM
- Culturing apparatus: Flasks, test volume: 250 mL
- Number of culture flasks/concentration: Test item: 2; Blanks: 3; Reference compound: 2
- Method used to create aerobic conditions: continuous stirring (magnetic stirrer)
- Measuring equipment: Oxi Top System (WTW). The consumption of oxygen was determined by measuring the quantity of oxygen (produced electrolytically) required to maintain constant gas volume in the respirometer flask. Evolved carbon dioxide was absorbed in a solution of potassium hydroxide.
- Test performed in closed vessels due to significant volatility of test substance: Closed vessels to be able to measure the oxygen consumption.


SAMPLING
- Sampling frequency: Daily
- Sampling method: Per day the flasks the oxygen uptake was calculated from the readings of the Oxitop system using the method given by the manufacturer of the equipment.


CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, in triplicate
- Toxicity control: yes

Reference substance:

benzoic acid, sodium salt

Remarks:

concentration: 100 mg/L

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

Within 28 days, a degradation of 0.0% was determined for the test substance. No toxicity of the test item was observed in the toxicity control (40.2% degradation).
The oxygen uptake by nitrification was determined. The oxygen consumed by nitrification was 4.20 mg/L. This oxygen consumption by nitrification was subtracted from the respective 28 days measurements of the test substance.

Results with reference substance:

The reference substance sodium benzoate showed 84.5% degradation after 14 days.

Interpretation of results:

under test conditions no biodegradation observed

Description of key information

The test substance is not readily biodegradable according to OECD criteria under conditions tested.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

One GLP guideline study investigating the ready biodegradability of test substance is available. During the manometric respirometry test (Neuhahn, 2007) conducted according to EU Method C.4-D with activated sludge as inoculum and a test substance concentration of 100 mg/L, no degradation (0.0%) was observed after 28 days.

According to OECD criteria the test substance is not readily biodegradable.