1-(2-Ethylbutyl)cyclohexanecarbonitrile

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

other information

Study period:

July 30,2008 to October 16,2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

- Commission Directive 92/69/EEC, Method C.4-D of July 3 1, 1992: Manometric Respirometry Test (EEC Publication No. L 383 A, December 1992) - OECD Guideline for Testing of Chemicals No. 301 F: “Ready Biodegradability: Manometric Respirometry Test”, adopted July 17, 1992

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

CAT-Nitrile

IUPAC Name:

CAT-Nitrile

Details on test material:

Name: CAT-Nitril
Certificate of Analysis Date: June 27,2008
Theoretical Oxygen Demand: ThODNH4: 2.878 mg oxygen per mg test item
ThODNO3: 3.188 mg oxygen per mg test item
Physical Appearance / Colour: Liquid / Colourless - light brown
Solubility: Not available
Expiry Date: December 27,2008
Stability: In water: test item is considered to be stable under
test conditions
Storage: In original container, at room temperature (10 -
30°C), in the dark

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

0.103 mg/L

Based on:

test mat.

Results and discussion

Details on results:

Biodegradation of Test Item:

ThODNH4

The occurrence of nitrification was considered but not
experimentally confirmed. The nitrification was not determined
by means of an analytical method because the
biodegradation rate was not higher than 60% based on ThODNH4.

After correction for the mean biochemical oxygen demand
of the inoculum controls the mean percentage biodegradation
based on ThODNH4a t the end of the 10-day
window was -2% (mean value).

At the end of the 28-day exposure period degradation
rates of -2% (ThODNO3) were found.

Conclusion:
The degradation rate of CAT-Nitril did not
reach 60% within the 10-day window and after 28 days of
incubation when no nitrification is considered.

According to the test guideline, CAT-Nitril
is considered not to be readily biodegradable.

Applicant's summary and conclusion

Validity criteria fulfilled:

not applicable

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The degradation rate of CAT-Nitril did not
reach 60% within the 10-day window and after 28 days of
incubation when no nitrification is considered.

According to the test guideline, CAT-Nitril
is considered not to be readily biodegradable.

Executive summary:

Title:

Ready Biodegradability of CAT-Nitril, in a

Manometric Respirometry Test

 

Guidelines:

- Commission Directive 92/69/EEC, Method C.4-D of

July 3 1, 1992: Manometric Respirometry Test (EEC

Publication No. L 383 A, December 1992)

- OECD Guideline for Testing of Chemicals No. 301 F:

“Ready Biodegradability: Manometric Respirometry

Test”, adopted July 17, 1992

 

Material and Methods:

Test Item:

CAT-Nitril

 

Test Species:

Aerobic activated sludge (micro-organisms from a domestic

wastewater treatment plant) was supplied by the sewage

works of Darmstadt, Germany.

 

Test Design:

The test item CAT-Nitril was investigated for

its ready biodegradability in a manometric respirometry test

over a period of 28 days. The biodegradation was followed

by the oxygen uptake of the micro-organisms during exposure.

As a reference item sodium benzoate was tested simultaneously

under the same conditions as the test item, and

functioned as a procedure control.

 

Endpoints:

Degradation rate of the test item calculated by the oxygen

consumption of the aerobic activated sludge microorganisms

after 28 days of incubation.

 

Test Item Loading Rate:

104 mg/L corresponding to an oxygen demand of about

299 mg/L (ThODNH4) and 332 mg/L (ThODNO3)

 

Reference Item:

Sodium Benzoate

 

Reference Item Loading Rate:

102 mg/L corresponding to an oxygen demand of about

170 mg/L (ThODNH4)

 

Test Conditions:

20-22 degree C, darkness

 

Results:

Biodegradation of CAT-Nitril:

The test item CAT-Nitril contains nitrogen,

therefore the evaluation of biodegradation has to be based

on ThODNH4 and ThODNO3. The criterion for ready biodegradability

under the conditions of a manometric respirometry

test is the 10-day window, describing the period between

reaching at least 10% degradation and 60% degradation.

This period should not exceed 10 days.

 

The mean biodegradation after 28 days of CAT-Nitril was -2% (ThODNH4) and -2% (ThODNO3) at the 10 day window criterion was not passed.

 

Therefore, CAT-Nitril is considered not to be

readily biodegradable.

 

Biodegradation of Sodium Benzoate:

The reference item sodium benzoate was sufficiently degraded

to 97% after 14 days and also to 97% after 28 days

of incubation, thus confirming the suitability of the aerobic

activated sludge inoculum used.

 

Biodegradation of the Toxicity Control:

In the toxicity control containing both, the test item and the

reference item sodium benzoate, a mean of 32% biodegradation

was noted within 14 days and also 32% biodegradation

after 28 days of incubation. Thus, the test item can be

assumed to be not inhibitory to the aerobic activated sludge

micro organisms.