Disodium 5,5'-[(1-methylethylidene)bis(4,1-phenyleneoxysulphonyl-2,1-phenyleneazo)]bis[6-amino-4-hydroxynaphthalene-2-sulphonate]

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 initiation date -18 May 1995; Experimental starting date - 31 May 1995; Experimental termination date - 28 June 1995; Study completion date - 30 August 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 C (Inherent Biodegradability: Modified MITI Test (II))

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Code number: FAT 21021/D
Batch-No.: 9
Purity: ca 70 %
Appearance: solid
Solubility: 30 g/l
Storage: room temperature
Expiration: 12/99

Oxygen conditions:

aerobic

Inoculum or test system:

not specified

Details on inoculum:

Mixture of polyvalent bacteria collected on May 30, 1995 in the aeration tank of a domestic sewage treatment plant, PRO RHENO Basel communal.

Duration of test (contact time):

28 d

Initial conc.:

30 mg/L

Based on:

ThOD

Parameter followed for biodegradation estimation:

TOC removal

Parameter:

other: ThOD

Value:

0

Sampling time:

28 d

Details on results:

Biodegradation after 28 days of the test substance for FAT 21021/D was found to be 0 %.

Results with reference substance:

The biodegradation of the reference substance corrected by the inoculum control and measured as BOO versus ThOD is;
74 % after 7 days
74 % after 14 days
70 % after 28 days.

Biodegradation after 28 days of the test substance FAT 21021/D is 0 %. ThOD is 1.52 mg O2/mg (ThOD calculated without nitrification).

Validity criteria fulfilled:

yes

Interpretation of results:

not inherently biodegradable

Conclusions:

FAT 21021/D is not biodegradable (0 % after 28 days).

Executive summary:

A key study was performed to determine the inherent biodegradability of FAT 21021/D in a 28 days MITI Test according to the OECD Guideline for Testing of Chemicals, No. 302C. This study was performed in compliance with Good Laboratory Practice (GLP). The test substance was tested in a concentration of 30 mg/l. The reference substance (Sodium benzoate) was tested in a concentration of 100 mg/L. Biodegradation after 28 days of the reference substance is 74 %. Biodegradation after 28 days of the test substance for FAT 21021/D was 0 %. Therefore, FAT 21021/D can be considered as not biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study initiation date -18 May 1995; Experimental starting date - 31 May 1995; Experimental termination date - 28 June 1995; Study completion date - 30 August 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 C (Inherent Biodegradability: Modified MITI Test (II))

Deviations:

no

GLP compliance:

no

Specific details on test material used for the study:

Code number: FAT 21021/D
Batch-No.: 9
Purity: ca. 70 %
Appearance: solid
Solubility: 30 g/l
Storage: room temperature
Expiration: 12/99

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

Remarks on result:

other: BOD values determined

Parameter:

BOD5

Value:

0 mg O2/g test mat.

Validity criteria fulfilled:

not specified

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

BOD5 of FAT 21021/D was found to be 0 mg O2/g.

Executive summary:

A key study was performed to determine the BOD of FAT 21021/D in a 28 days MITI Test according to the OECD Guideline for Testing of Chemicals, No. 302C. This study was performed in compliance with Good Laboratory Practice (GLP). The test substance was tested in a concentration of 30 mg/l. Based on the findings of this study, the BOD5 of FAT 21021/D was found to be 0 mg O2/g. In another study conducted for determination of COD for FAT 21021/D, the value was found to 1358 mg O2/g. The resultant BOD/COD value was found to be Zero indicating the substance is not biodegradable.

Reference 3

Endpoint:

biodegradation in water: screening tests

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study initiation date - 02 March 1995; Experiment start and end date - 09 March 1995; Study completion date - 03 April 1995.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.6 (Degradation: Chemical Oxygen Demand)

Deviations:

yes

Remarks:

Mean of 2 determinations instead of 3

GLP compliance:

yes

Specific details on test material used for the study:

Code number: FAT 21021/D
Batch-Nr.: 9
Purity: ca. 70 %
Appearance: solid
Solubility: 30 g/l
Storage: room temperature
Expiration: 12/99

Oxygen conditions:

not specified

Inoculum or test system:

not specified

Duration of test (contact time):

2 h

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

Sample weight: 6.23 and 6.24 mg of the test substance
Temperature: 148 ± 3 °C
Duration: 2 hours
Estimation Technique: Titration (potentiometric) METROHM Titroprozessor 670 (SAV : 00 111)

Reference substance:

other: Potassium hydrogen phthalate solution (Merck-Nr. 11769)

Remarks on result:

not measured/tested

Parameter:

COD

Value:

1 358 mg O2/g test mat.

Results with reference substance:

The COD of Potassium hydrogen phthalate is 198 mg O2/L

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The COD of the test substance for FAT 21021/D was found to be 1358 mg O2/g.

Executive summary:

A key study was carried out to determine chemical oxygen demand of FAT 21021/D according to DIN 38409- H 41-1 (1980) corresponding to EEC Directive 92/69/ C.6. (1992). A pre-determinated amount of the test substance in water which is oxidized by potassium dichromate in a strong sulphuric acid medium with silver sulphate as a catalyst under reflux for 2 hours. The residual dichromate is determined by titration with standardized ferrous ammonium sulphate. This study will be performed in compliance with Good Laboratory Practice (GLP). The test substance was tested with a sample weight of 6.23 and 6.24 mg. The reference substance was Potassium hydrogen phthalate. lt was tested with 20 ml of a 0.17 g/l solution. The COD of the reference substance was 198 mg O2/L. The COD of FAT 21021/D was 1358 mg O2/g.

Description of key information

The inherent biodegradability of FAT 21021/D determined in a 28 days MITI Test was "0 %" and the BOD5/COD quotient is not >0.5. Therefore, the test substance FAT 21021 can be regarded as not biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

The inherent biodegradability of the test substance FAT 21021 was determined in a GLP-compliant study in Zahn-Wellens / EMPA Test according to OECD Guideline 302C. The test substance FAT 21021 and the reference substance Sodium benzoate, respectively, were tested in concentrations of 100 mg/I. The biodegradation of the test substance FAT 21021 after 28 days was 0 %. The COD estimation was done in GLP-compliant studies according to ISO 5815 and EEC 92/69/C.6 (1992), respectively. The biochemical oxygen demand of FAT 21021 was determined by measuring the dissolved oxygen concentration before and after 5 days incubation at 20 °C in different test concentrations diluted in water saturated with dissolved oxygen that contains a seed of micro-organisms. In another key study the biochemical oxygen demand of FAT 21021 was determined by measuring the dissolved oxygen concentration before and after 5 days incubation at 20 °C in different test concentrations diluted in water saturated with dissolved oxygen that contains a seed of micro-organisms. The BOD5 and COD of FAT 21021 was found to be 0 mg O2/g and 1358 mg O2/g, respectively. Few non-GLP compliant studies performed in the 70’s have reported the following BOD5 and COD values for FAT 21021:

BOD5 = 130 mg/g O2

COD = 11840 mg/g O2

 

Relevant is the BOD5/COD quotient which is not >0.5, therefore the substance is not indicative of rapid degradation. Taking the data from key study and supporting studies into account, the test substance FAT 21021 can be regarded as not biodegradable.