Sodium 6-amino-5-[[2-[(cyclohexylmethylamino)sulphonyl]phenyl]azo]-4-hydroxynaphthalene-2-sulphonate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: screening tests

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: In house guideline compatable to internationally accepted guidelines

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

5 d

Test performance:

None

Remarks on result:

not measured/tested

Parameter:

BOD5

Value:

0 mg O2/g test mat.

Validity criteria fulfilled:

not specified

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The Biological Oxygen Demand of FAT 20003/H was determined to be 0 mg O2/g test mat.

Executive summary:

The Biological Oxygen Demand of FAT 20003/H was determined to be 0 mg O2/g test mat.

Reference 2

Endpoint:

biodegradation in water: screening tests

Remarks:

COD determination

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: DIN 38409-H41-1.

Deviations:

not specified

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

other: Not applicable

Remarks on result:

not measured/tested

Parameter:

COD

Value:

572 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 20003/H was determined to be 572 mg O2/g test mat.

Executive summary:

The Chemical Oxygen Demand of FAT 20003/H was determined to be 572 mg O2/g test mat.

Reference 3

Endpoint:

biodegradation in water: screening tests

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 12 November, 1997 to 04 February, 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Code no.: FAT 20003/I
Batch no.: Vers. Nr. 9-5-97
Purity: ca. 90 %
Appearance: red powder
Solubility: 30 g/L
Storage: room temperature
Expiration date: 02/2001

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Activated sludge of a communal sewage treatment plant (ARA Pro Rheno Basel) collected on January 06, 1998 was washed twice with tap water one day before the test was started.

Duration of test (contact time):

28 d

Initial conc.:

51 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

Performance of the test:
A mixture of a total test volume of 2 L each containing test substance, mineral medium and activated sludge was agitated and aerated at 20-25 °C in two glass vessels for 28 d. A reference control running in duplicate containing activated sludge, mineral medium and the reference substance, and a blank control containing activated sludge and mineral medium were run under the same test conditions. The biodegradation process was monitored by determination of the dissolved organic carbon concentrations (DOC). The ratio of eliminated DOC, corrected for the blank after each time interval, to the initial DOC value was expressed as the percentage biodegradation at each sampling time. The concentration of dissolved oxygen was checked at regular intervals to ensure that the oxygen did not fall below 2 mg/L. The pH was checked and adjusted to pH 7 - 8 if necessary.

Experimental conditions:
Temperature: 20.0 - 22.3 °C
pH: 7.0 - 7.3
O2: 7.2-8.6 mg/L
Sludge dry weight: 0.20 g/L
DOC of distilled water: 0 mg/L
DOC content of test substance: 47.3 %
Amount of test substance (conc.): 106 mg/L
Test volume: 2 L
Test duration: 28 d
Aeration: Continuously aerated by passing fritted glass
Agitation: Continuously stirred with a magnetic stirrer
Lighting: Diffuse daylight

Reference substance:

diethylene glycol

Preliminary study:

no data

Test performance:

no data

Parameter:

% degradation (DOC removal)

Value:

16

Sampling time:

28 d

Details on results:

Adsorption of the test substance after 3 h: 1 %
Biodegradation of the test substance after 28 d: 16 %
Total elimination (regarding adsorption and biodegradation) of the test substance after 28 d: 17 %

Results with reference substance:

The reference substance was removed by more than 70 % in the first 14 d.

Table 1: Tables of details:

	DOC concentration (mg/L)				Biodegradation (%)
Time	Reference mean	Blank	Substance 1	Substance 2	Reference mean	Substance 1	Substance 2
Start	51	-	51	51	-	-	-
3h	52	2	53	52	-	-	-
Day 1	56	7	53	52	2.0	9.8	10.0
Day 7	48	7	54	54	18.0	7.8	6.0
Day 13	7	3	52	53	92.0	3.9	0.0
Day 14	6	5	-	-	98.0	-	-
Day 21	-	4	49	48	-	11.8	12.0
Day 27	-	5	48	45	-	15.7	20.0
Day 28	-	5	47	48	-	17.6	14.0

Adsorption after 3 h in % mean	1
Biodegradation after 28 d in % mean	16
Total Elimination after 28 d in % mean	17

 

*Negative values or values above 100 % are given as 0 % and 100 %, respectively.

Validity criteria fulfilled:

yes

Remarks:

(reference substance was removed by more than 70 % in the first 14 d)

Interpretation of results:

not inherently biodegradable

Conclusions:

The test substance is not considered to be inherently biodegradable.

Executive summary:

An inherent biodegradability study was conducted with the test substance according to OECD Guideline 302 B and EU Method C.4-C in compliance with GLP.

Mixtures of a total volume of 2 L containing test substance, mineral medium and activated sludge were agitated and aerated at 20 - 25 °C in two glass vessels for 28 d. A reference control running in duplicate containing activated sludge, mineral medium and the reference substance, and a blank control containing activated sludge and mineral medium were run under the same conditions. The biodégradation process was monitored by determination of the dissolved organic carbon concentrations (DOC). The ratio of eliminated DOC, corrected for the blank after each time interval, to the initial DOC value was expressed as the percentage biodégradation at each sampling time.

The following result were obtained:

Adsorption of the test substance after 3 h: 1 %

Biodegradation of the test substance after 28 d: 16 %

Total elimination (regarding adsorption and biodegradation) of the test substance after 28 d: 17 %

Based on the above findings, it was concluded that under the study conditions, the test substance was inherently biodegradable.

Description of key information

FAT 20003 is not rapidly biodegradable, but fulfils the criteria of primary, inherent biodegradability.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable, fulfilling specific criteria

Type of water:

freshwater

Additional information

Several studies evaluating the biodegradability of FAT 20003 are available, which included studies to determine the inherent biodegradability, as well as chemical oxygen demand (COD) and biological oxygen demand (BOD5).

BOD5/COD ratio:

The BOD5 and COD for FAT 20003/H were determined to be 0 and 572 mg/g O2 respectively, hence the BOD5/COD ratio was equal to 0.

The BOD5 and COD for FAT 20003/G were determined to be 53 and 1334 mg/g O2 respectively, hence the BOD5/COD ratio was equal to 0.04.

The BOD5 and COD for FAT 20003/F were determined to be 25 and 1014 mg/g O2 respectively, hence the BOD5/COD ratio was equal to 0.02.

The BOD5 and COD for FAT 20003/D were determined to be 170 and 1207 mg/g O2 respectively, hence the BOD5/COD ratio was equal to 0.14.

The BOD5/COD ratios in all above cases is <0.5, hence the substance should be considered as not rapidly biodegradable.

Inherent biodegradability:

In the key inherent biodegradability study (Zahn-Wellens/EMPA Test) with FAT 20003/I conducted according to OECD 302B, results indicated that Adsorption after 3 hours was 1 %, biodegradation after 28 days was 16 %, and total elimination after 22 days 17 %. Therefore, the test substance was determined to be non-biodegradable.

However, two other inherent biodegradability studies conducted with FAT 20003/H and FAT 20003/A indicated that the substance may fulfil the criteria for primary, inherent biodegradability by showing biodegradation 20 %.