Trisodium bis[3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-4-hydroxy-5-nitrobenzenesulphonato(3-)]chromate(3-)

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: screening test, other

Remarks:

Determination of the biological oxygen demand and the chemical oxygen demand

Type of information:

other: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: See 'Remarks'

Remarks:

Basic data given, acceptable for assessment. The results of the study were reported until the early 1980s in summary reports which do not present details of the methods used, but focus on a summary presentation of results. Justification for Read Across is detailed in the endpoint summary.

Principles of method if other than guideline:

Determination of the biological oxygen demand and the chemical oxygen demand were performed according to published methods, which were adapted and standardized for the specific needs of the company, well before Test Guidelines for these methods were established by the OECD beginning 1981.

GLP compliance:

no

Remarks:

pre GLP

Inoculum or test system:

other: sewage treatment plant

Duration of test (contact time):

5 d

Initial conc.:

100 mg/L

Based on:

test mat.

Initial conc.:

200 mg/L

Based on:

test mat.

Initial conc.:

400 mg/L

Based on:

test mat.

Initial conc.:

500 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

FILTRATION
The sample is adjusted to pH 7 and filtered through a Whatman GF/A filter. The O2 determination of the filtrate represents the BOD of the real dissolved oxygen amount.

SEDIMENTATION
A sample of the test water is adjusted to pH 7 and sedimented with the help of an Imhoff-Cone. The BOD Determination in the supernatant is the BOD of the real dissolved organic substances including the suspended matter.

HOMOGENIZATION
In case BOD of crassly dispersed needs to be included the pH 7-adjusted sample needs to be homogenized for 3 minutes in a lab homogenizer. During the 5-day incubation period the vessels must be shaken frequently to avoid sedimentation of non-dissolved particles. BOD5-determination is done including an filtration step as indicated above.

INOCULUM
To dilute test samples demineralised water with following nutrients are used:
Solution 1: 8.5 g KH2PO4, 21.75 g K2HPO4 33.4 g Na2HPO4x2H2O and 1.7 g NH4Cl are dissolved in 500 ml deionised water and filled up to a total volume of 1 litre. The pH-value should be 7.2
Solution 2: 22.5 g MgSO4x7H2O is dissolved in deionised water and adjusted to a total volume of 1 litre.
Solution 3: 27.5 g CaCl2 is dissolved in deionised water and adjusted to a total volume of 1 litre.
Solution 4: 0.25 g FeCl3 x6H2O is dissolved in deionised water and adjusted to a total volume of 1 litre.

1 ml of solutions 1-4 are added to 1 litre of deionised water and inoculated with bacteria from the underrun of a sewage treatment plant. The underrun is filtrated through a Whatman GF/A filter before incubation and 2 ml of the filtrate should be used for inoculation of 1 litre of dilution solution (10^5 bacteria/ml). The resulting dilution water must be aerated for 2 to 3 days until it is totally ablated and saturated with oxygen (about 8 mg/l oxygen).
To avoid algal growth the dilution water should be kept in the dark.

PREPARATION of a DILUTION SERIES
Optimum Range: Joyce of an optimum dilution of a substance to investigate is important because for the calculation at the end of the test a vessel is selected having about 2 to 2.5 mg/l of oxygen remaining in the sample while the oxygen consumption should be 4 mg/l at a minimum (that means at about 50 % of the initial oxygen content). In addition it has to be considered that after 5 days of incubation the oxygen consumption of the blank control should be smaller than 0.5 mg/g.
Cases showing higher oxygen consumption within the first 5 days do not show pure aerobe biodegradation, therefore these samples can’t be used. This is the case in all samples having less than 2 mg/l oxygen after 5 days.
Three stock solutions are prepared from each test material at 0.1, 1.0 and 10.0 g/litre. These will be further diluted and bottled in special BOD vessels.

PREPARATION of the TEST SAMPLES
Of each stock solution 2 different samples are prepared (5 and 25 ml) and filled up with dilution water to a total volume of 0.5 litre.
e.g. 0.1 g/l of stock solution 5 ml add. dilution water to a final volume of 0.5 litre and 25 ml add. dilution water to a final volume of 0.5 litre.

Remarks on result:

not measured/tested

Parameter:

BOD5

Value:

27 mg O2/g test mat.

Parameter:

COD

Value:

1 021 mg O2/g test mat.

COD

Titre: 14.36 ml

Norm.: 0.2176 ml

Blank: 14.12 ml

Back-titre: 11.13 ml

Consumption: 2.99 ml

Sample weight: 5 ml

1040.99 mg COD/g

19.98 mg COD/Cl

BOD

Blank value: 8.2 at start; after 5 days: 7.8.

Diff: 0.4

Standard solution (g/l)	Beginning ml/500 ml	Concentration (mg/l)	Value	Blank value	Diff.	5-day value		Factor	O2 mg/g
10	5 ml	100	8.2	0.4	7.8	5 5	5	10	28
	10 ml	200	8.3	0.4	7.9	2.5 2.5	2.5	5	27
	20 ml	400	8.2	0.4	7.8	-	-	2.5	-
	25 ml	500	8.2	0.4	7.8	-	-	2	-

Result: 200 mg/l

O₂: 27

Interpretation of results:

not readily biodegradable

Conclusions:

Not readily biodegradable.

Executive summary:

Method

The BOD5:COD ratio was calculated using the values resulted from the specific studies for both BOD5 and COD determination. Both were performed according to published methods, which were adapted and standardized for the specific needs of the company, well before Test Guidelines for these methods were established by the OECD beginning 1981.

Results

BOD5: 27 mg/g O₂

COD: 1021 mg/g O₂

BOD5/COD: 0.03

Conclusion

The ration BOD5:COD resulted lower than 0.5; according to the ECHA "Guidance on information requirements and chemical safety assessment - Chapter R.7b: Endpoint specific guidance" (May 2008 version 1.1), if the BOD5:COD ratio is lower than 0.5, it can be expected that the substance is not readily biodegradable; therefore it can be concluded that the substance is expected as not readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: screening test, other

Remarks:

Determination of the biological oxygen demand and the chemical oxygen demand

Type of information:

other: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Test procedures are scientifically acceptable, nevertheless many detail are missing. The results of the study were reported until the early 1980s in summary reports which do not present details of the methods used, but focus on a summary presentation of results. Justification for Read Across is detailed in the endpoint summary.

Principles of method if other than guideline:

Determination of the biological oxygen demand and the chemical oxygen demand were performed according to published methods, which were adapted and standardized for the specific needs of the company, well before Test Guidelines for these methods were established by the OECD beginning 1981.

GLP compliance:

no

Remarks:

pre GLP

Inoculum or test system:

other: sewage treatment plant

Duration of test (contact time):

5 d

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

FILTRATION
The sample is adjusted to pH 7 and filtered through a Whatman GF/A filter. The O2 determination of the filtrate represents the BOD of the real dissolved oxygen amount.

SEDIMENTATION
A sample of the test water is adjusted to pH 7 and sedimented with the help of an Imhoff-Cone. The BOD Determination in the supernatant is the BOD of the real dissolved organic substances including the suspended matter.

HOMOGENIZATION
In case BOD of crassly dispersed needs to be included the pH 7-adjusted sample needs to be homogenized for 3 minutes in a lab homogenizer. During the 5-day incubation period the vessels must be shaken frequently to avoid sedimentation of non-dissolved particles. BOD5-determination is done including an filtration step as indicated above.

INOCULUM
To dilute test samples demineralised water with following nutrients are used:
Solution 1: 8.5 g KH2PO4, 21.75 g K2HPO4 33.4 g Na2HPO4x2H2O and 1.7 g NH4Cl are dissolved in 500 ml deionised water and filled up to a total volume of 1 litre. The pH-value should be 7.2
Solution 2: 22.5 g MgSO4x7H2O is dissolved in deionised water and adjusted to a total volume of 1 litre.
Solution 3: 27.5 g CaCl2 is dissolved in deionised water and adjusted to a total volume of 1 litre.
Solution 4: 0.25 g FeCl3 x6H2O is dissolved in deionised water and adjusted to a total volume of 1 litre.

1 ml of solutions 1-4 are added to 1 litre of deionised water and inoculated with bacteria from the underrun of a sewage treatment plant. The underrun is filtrated through a Whatman GF/A filter before incubation and 2 ml of the filtrate should be used for inoculation of 1 litre of dilution solution (10^5 bacteria/ml). The resulting dilution water must be aerated for 2 to 3 days until it is totally ablated and saturated with oxygen (about 8 mg/l oxygen).
To avoid algal growth the dilution water should be kept in the dark.

PREPARATION of a DILUTION SERIES
Optimum Range: Joyce of an optimum dilution of a substance to investigate is important because for the calculation at the end of the test a vessel is selected having about 2 to 2.5 mg/l of oxygen remaining in the sample while the oxygen consumption should be 4 mg/l at a minimum ( that means at about 50 % of the initial oxygen content). In addition it has to be considered that after 5 days of incubation the oxygen consumption of the blanc control should be smaller than 0.5 mg/g.
Cases showing higher oxygen consumption within the first 5 days do not show pure aerobe biodegradation, therefore these samples can’t be used. This is the case in all samples having less than 2 mg/l oxygen after 5 days.
Three stock solutions are prepared from each test material at 0.1, 1.0 and 10.0 g/litre. These will be further diluted and bottled in special BOD vessels.

PREPARATION of the TEST SAMPLES
Of each stock solution 2 different samples are prepared (5 and 25 ml) and filled up with dilution water to a total volume of 0.5 litre.
e.g. 0.1 g/l of stock solution 5 ml add. dilution water to a final volume of 0.5 litre and 25 ml add. dilution water to a final volume of 0.5 litre.

Remarks on result:

not measured/tested

Parameter:

BOD5

Value:

54 mg O2/g test mat.

Parameter:

COD

Value:

1 055 mg O2/g test mat.

COD

Titre: 13.80 ml

Norm.: 0.2265 ml

Blank: 13.65 ml

Back-titre: 10.70 ml

Consumption: 2.95 ml

Sample weight: 5 ml

1069.08 mg COD/g

1054.69 mg COD/Cl

BOD

Blank value: 8.1 at start; after 5 days: 7.5.

Diff: 0.6

Standard solution (g/l)	Beginning ml/500 ml	Concentration (mg/l)	Value	Blank value	Diff.	5-day value		Diff.	Factor	O2mg/g
0.1	5 ml	1	8.2	0.6	7.6	7.6	7.6	0	1000	-
						7.6
	25 ml	5	8.2	0.6	7.6	7.3	73	0.3	200	60
						7.3
1	5 ml	10	8.3	0.6	7.7	7.1	7.1	0.6	100	60
						7.1
	10 ml	20	8.2	0.6	7.6	6.6	6.6	1	50	50
						6.6
	25 ml	50	8.3	0.6	7.7	5.1	5.1	2.6	20	52
						5.1
10	5 ml	100	8.5	0.6	7.9	2.5	2.5	5.4	10	54
						2.5
	10 ml	200	8.5	0.6	7.9	-	-	-	5	-
						-
	25 ml	500	8.3	0.6	7.7	-	-	-	2	-
						-

Result: 100 mg/l

O₂: 54

Interpretation of results:

not readily biodegradable

Conclusions:

Not readily biodegradable.

Executive summary:

Method

The BOD5:COD ratio was calculated using the values resulted from the specific studies for both BOD5 and COD determination. Both were performed according to published methods, which were adapted and standardized for the specific needs of the company, well before Test Guidelines for these methods were established by the OECD beginning 1981.

Results

BOD5: 54 mg/g O₂

COD: 1055 mg/g O₂

BOD5/COD: 0.05

Conclusion

The ration BOD5:COD resulted lower than 0.5; according to the ECHA "Guidance on information requirements and chemical safety assessment - Chapter R.7b: Endpoint specific guidance" (May 2008 version 1.1), if the BOD5:COD ratio is lower than 0.5, it can be expected that the substance is not readily biodegradable; therefore it can be concluded that the substance is expected as not readily biodegradable.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Remarks:

prediction

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

QSAR estimation

Qualifier:

no guideline required

Principles of method if other than guideline:

QSAR dyes R&C report produced by version QSAR dyes RC 2.0 Developed by Milano Chemometrics and QASR research group Dept. Earth and Environmental Science, University Milano
Bicocca, Italy.

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Remarks on result:

not readily biodegradable based on QSAR/QSPR prediction

Validity criteria fulfilled:

not applicable

Remarks:

estimation by prediction tool

Interpretation of results:

not readily biodegradable

Conclusions:

Based on prediction carried out with the prediction tool, the substance resulted as non ready biodegradable.

Executive summary:

Results

The substance was predicted to be not ready biodegradable.

Description of key information

Expected as not readily biodegradable.

Additional information

No experimental, nor literature data are available about the biodegradation potential of Acid Red 357 (AR357), thus the available data on the structural analogue Acid Red 315 (AR315 - Similar Substance 01) were considered.

The biodegradation potential of the AR315 was investigated in two studies performed according to published methods, which were adapted and standardized for the specific needs of the company, well before Test Guidelines for these methods were established by the OECD beginning 1981. The ration BOD5:COD resulted lower than 0.5; according to the ECHA "Guidance on information requirements and chemical safety assessment - Chapter R.7b: Endpoint specific guidance" (May 2008 version 1.1), if the BOD5:COD ratio is lower than 0.5, it can be expected that the substance is not readily biodegradable; therefore it can be concluded that the substance is expected as not readily biodegradable.

In general, acid dyes are chemicals not readily biodegradable: in fact, they are synthetized and designed for specific uses and the resistance to a rapidly degradation is a desired property.

Both AR357 and AR315 are chromate pyrazol sodium salts: AR357 is a trisodium, while AR315 is a disodium salt. They share the same structure, except for the fact that AR357 has two sulphonated groups, instead one as AR315. It is expected that this difference has not impact on the potential of biodegradability.