5-[(4-chloro-2-nitrophenyl)azo]-1-ethyl-1,2-dihydro-6-hydroxy-4-methyl-2-oxonicotinonitrile

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study completion date: 10 January 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

Deviations:

not specified

GLP compliance:

not specified

Specific details on test material used for the study:

Name; FAT 36091/E
Purity: 16.1%

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

28 d

Initial conc.:

147 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

TOC removal

Parameter:

% degradation (TOC removal)

Value:

60

Sampling time:

28 d

Validity criteria fulfilled:

not specified

Interpretation of results:

inherently biodegradable

Conclusions:

The inherent elimination after 28 days exposure time was found to be 60 % TOC.

Executive summary:

The Zahn-Wellens study was performed on FAT 36091/E using the OECD Guideline 302B. The initial test concentration was 147 mg/L TOC. After 28 days of exposure, the biodegradatoion was found to 60 % TOC. FAT 36091/E is inherently biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study completion date: 21 October 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: Internal CIBA guideline, Method A-16

Version / remarks:

Comparable to internationally accepted guidelines. The method is described in the section: "Any other information on materials and methods incl tables".

Deviations:

not specified

Principles of method if other than guideline:

Determination of the chemical oxygen demand (COD).

GLP compliance:

no

Specific details on test material used for the study:

Name; FAT 36091/E
Purity: 16.1 %

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Initial conc.:

5 mg/L

Based on:

COD

Parameter followed for biodegradation estimation:

O2 consumption

Parameter:

other: COD

Remarks on result:

other: COD determination

Parameter:

COD

Value:

1 455 mg O2/g test mat.

Validity criteria fulfilled:

not specified

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The Chemical Oxygen Demand of FAT 36091/E was detremined to be 1455 mg/g COD.

Executive summary:

The Chemical Oxygen Demand (COD) of FAT 36091/E was determined according to in house Ciba Geigy Methode A.16. The initial concentration was 5 mg/L. Based on the findings of the study, the COD of test substance was found to be 1455 mg COD/g. For the test material, the BOD5 was calculated to be 0 mg O2/g, respectively, which gives the BOD5/COD ratio of 0 proving the test substance to be not rapidly biodegradable.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Test beginn: 16 October 1987 and test end: 21 October 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: Internal CIBA guideline Method A-15

Version / remarks:

Comparable to internationally accepted guidelines. The method is described in the section: "Any other information on materials and methods incl tables".

Deviations:

no

GLP compliance:

no

Specific details on test material used for the study:

Name: FAT 36091/E
Purity: 16.1 %

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

5 d

Parameter followed for biodegradation estimation:

O2 consumption

Parameter:

other: BOD

Remarks on result:

other: BOD determination

Parameter:

BOD5

Value:

0 mg O2/g test mat.

BOD5:

Standard solution	Preparation	Test concentration	Initial value	Blank or blind value	Difference	Value after 5 days	Mean	Difference	Factor	O2 mg/gr
0.1 g/l	5 ml	1	8.9	0.6	8.3	8.3/8.4	8.4	-	1000	-
0.1 g/l	25 ml	5	8.9	"	8.3	8.5/8.5	8.5	-	200	-
1.0 g/l	5 ml	10	8.9	"	8.3	8.5/8.5	8.5	-	100	-
1.0 g/l	10 ml	20	8.9	"	8.3	8.0/8.4	8.2	0.1	50	5
1.0 g/l	25 ml	50	8.9	"	8.3	8.3/8.4	8.4	-	20	-
10.0 g/l	5 ml	100	8.9	"	8.3	8.2/8.1	8.2	0.1	10	1
10.0 g/l	10 ml	200	8.9	"	8.3	8.1/7.9	8.0	0.3	5	1.5
10.0 g/l	25 ml	500	8.9	"	8.3	7.1/7.0	7.1	1.2	2	2.4

BOD5 = 0 mg/gr. O2

Validity criteria fulfilled:

not specified

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The Biological Oxygen Demand of FAT 36091/E was detremined to be 0 mg/g O2.

Executive summary:

The Biological Oxygen Demand (BOD5) of FAT 36091/E was determined according to in house Ciba Geigy Method A.15, which is comparable to internationally accepted guidelines. Based on these investigations, the BOD5 of test substance was found to be 0 mg O2/g. Considering the COD value determined with the test substance which is 1455 mg O2/g, the resulting BOD5/COD quotient is 0, indicating that the test substance is unlikely to be biodegradable.

Description of key information

An Inherent biodegradability assessment was conducted to measure the biodegradability of the test item. In principle the methods described in OECD Guideline 302B were used (key study on batch E). The testing conditions represents a static method to test substances/products for degradation in activated sludge. Analysis is based on the Total Organic Carbon (TOC). The biodegradation of FAT 36091/E was found to be:

* 18.6 % after 3 hours of exposure time.

* 60 % TOC after 28 days exposure time.

In a second Inherent biodegradability assessment done to measure the biodegradability of the test item by following a method similar to OECD 302B showed 42 % DOC after 37 days. FAT 36091/E is considered to be inherently biodegradable after 28 days (60 % TOC after 28 days). Severals studies, (supporting studies), measuring BOD5 were performed on all batches and BOD5 was found to be 0 mg /g O2 in all experiment excepted for one batch (A) were BOD5 was measured to be 32 mg/g O2 . Since the BOD5 was measured to be zero, no ready biodegradation is expected to take place.

Several other supporting studies reported the following results:

COD (batch A): 1218.48 mg COD/g

COD (batch B): 1328.84mg COD/g.

COD (batch D): 1232.3 mg COD/g.

COD (batch E): 1455 mg/g COD.

COD (batch F): 1124 mg O2/g.

The above studies reported values greater than1000 mg/g for COD and BOD5 value as 0. Relevant is the BOD5/COD quotient which is “zero”, therefore biodegradation is not expected.Taking into consideration the data from two key studies, the test substance FAT 36091 is considered to be not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable