Carbamic acid, N,N'-methylenebis(4,1-cyclohexanediyl)bis-, C,C'-dibutyl ester

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:

2003-12-11 to 2004-01-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)

Version / remarks:

July 31, 1992

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

ISO DIS 9408 (Ultimate Aerobic Biodegradability - Method by Determining the Oxygen Demand in a Closed Respirometer)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4,4'-Methylenebis(N-butoxycarbonylcyclohexanamine)

EC Number:

619-422-7

Cas Number:

99305-42-7

Molecular formula:

C23 H42 N2 O4

IUPAC Name:

4,4'-Methylenebis(N-butoxycarbonylcyclohexanamine)

Details on test material:

- Test substance: 4,4'-Methylenebis(N-butoxycarbonylcyclohexanamine) of Degussa AG
- Batch 4/032, purity approximately 95 %, determined 04-Nov-2003
- white solid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

INOCULUM/TEST ORGANISM
- Source: Domestic STP D-65380 Kriftel, Mainstrasse 7-9
- Preparation of inoculum: twice 30 min sedimentation, decantation, and  resuspension in mineral medium, once with filtration; centrifugation,  
resuspension of 1 g/l in mineral medium; stirring and aeration until use

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

60 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST SYSTEM
- Culturing apparatus: 500 ml flasks filled with 250 ml test solution
- Number of culture flasks per concentration: 2 with test substance and inoculum; 2 with inoculum only (blank); 1 with reference substance and 
inoculum; 1 with test substance and 3,5-dichlorophenol (abiotic control); 1 with test and reference substances and inoculum (toxicity control,  
only 97 ml)
- Measuring equipment: manometer
- Closed vessels used: yes

TEST CONDITIONS
- Additional substrate: 10 mg/l N-allylthiourea (to prevent  nitrification; not in abiotic control)
- Test temperature: 22 +/- 1 °C - pH value: 7.3 - 7.6
- Concentration of suspended solids: 30 mg dry solids/l
- Other relevant factors: darkness

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

2 % degradation (28 days) in the toxicity control demonstrates that the test substance inhibits the microorganisms.

Kinetic of control substance (in %):
= 74 after 8 day(s)
= 90 after 28 day(s)

BOD5 / COD results

Results with reference substance:

- 80% degradation were observed within the first 12 days confirming the suitability of the used activated sludge
- 90% degradation were observed after 28 days

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The results demonstrate that the test item is not ready biodegradable under the present test conditions. The test item proved to inhibit the
microorganisms present in the activated sludge

Executive summary:

The biodegradation potential of H12MDU was investigated in a manometric respiratory test according to EU method C.4 -D and OECD TG 301 F. The oxygen consumption (BOD) was monitored at daily intervals (except for weekends and public holidays) over a period of 28 days. The study comprised seven test units (2 x test substance, 2 x inoculum control, 1 procedure control, 1 abiotic control, 1 toxicity control). No biodegradation of the test substance was observed under the present test condition. The results observed for the toxicity control demonstrate that the test substance inhibits the microorganisms present in the acitvated sludge.

The study was assessed as "reliable without restrictions".