Cyclohexane, 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethyl-, homopolymer, acetone oxime-blocked

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:

2001-04-19 to 2001-07-31

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline Study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "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:

- Source of inoculum/activated sludge: communal sewage plant Groß-Zimmern, Germany
- Preparation of inoculum for exposure: activated sludge was washed by centrifugation and the supernatant liquid phase was decanted; the solid material was resuspended in tap water and again centrifuged; this procedure was repeated twice; an aliquot of the final sludge suspension was weighed, dried and the ration of wet sludge to its dry weight was determined. Based on this ratio,
- Concentration of sludge: 1.5 g /L dw

Duration of test (contact time):

28 d

Initial conc.:

102.1 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: according to OECD 301 A
- Test temperature: 21-22 °C
- pH: 7.6
- pH adjusted: no
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: flasks, 500 mL, incubated in a cllimatic chamber under continuous stirring
- Number of culture flasks/concentration: 2 flasks containing the test substance, 2 inoculum blank, 1 procedure control, 1 abiotic control, 1 toxicity control
- Measuring equipment: BSB/BOD-Sensor-System
- amounts of test item and reference substance were directly weighted into the test flasks and solutions were stirred during the exposure period

SAMPLING
- Sampling frequency: at least once per day

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2
- Abiotic sterile control: 1
- Toxicity control: 1

Reference substance:

aniline

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

After correction of teh mean biochmical oxygen demand of the inoculum controls at the end of the 28-day exposure period degradation rates of -4% based on ThODNH4, were found.

Results with reference substance:

The reference item Aniline was sufficiently degraded: 87% after 14 days and 105% after 28 days of incubation.

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test substance can be considered to be not ready biodegradable

Executive summary:

The biodegradability of the test item was examined in a "Manometric Respirometry Test"-test according to EU-Method C.4 -D and OECD 301 F (IBACON GmbH 2001). Oxygen consumption was measured continuously (at least daily) over a period of 28 days. The test item was observed to be "not ready biodegradable" under the present test conditions (0% biodegradation within 28 days). The study was assessed as "reliable without restriction".

Description of key information

The biodegradability of the test item was examined in a "Manometric Respirometry Test"-test according to EU-Method C.4 -D and OECD 301 F (IBACON GmbH 2001). Oxygen consumption was measured continuously (at least daily) over a period of 28 days.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Additional information

The test item was observed to be "not ready biodegradable" under the present test conditions (0% biodegradation within 28 days).