Reaction mass of sodium(E)-6,7'-carbonylbis(azanediyl)bis(4-hydroxy-3-((E)-phenyldiazenyl) naphthalene-2-sulfonate) and disodium 3-[(4-acetamidophenyl)azo]-4-hydroxy-7-[[[[5-hydroxy-6-(phenylazo)-7-sulphonato-2-naphthyl]amino]carbonyl]amino]naphthalene-2-sulphonate and disodium 7,7'-(carbonyldiimino)bis[4-hydroxy-3-(phenylazo)naphthalene-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:

supporting study

Study period:

From 20 december to 17 january 2002

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

no

Remarks:

The study described in this report was conducted in accordance with SN EN 45001

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Activated sludge from the aeration tank of a municipal biological waste water treatment plant, not adapted, not pre-conditioned. O.2 g/l dry matter in the final mixture
- Feed: none, test substance or procedure control as sole organic carbon sources

TEST MEDIUM
Composition of the mineral salts medium:
- Stock solution I (pH 7.4) of 10 mg/L
Ammonium chloride, NH4Cl: 0.50 g
Di-sodium hydrogenphosphate, Na2H PO4 x 2 H2O: 33.40 g
Potassium dihydrogenphosphate, KH2PO4: 8.50 g
Di-potassium monohydrogenphosphate, K2HPO4: 21.75 g
- Stock solution II of 1 ml/L: Calcium chloride, anhydrous, CaCl2: 27.50 g
- Stock solution III of 1 ml/L: HzOMagnesium sulfate, MgSO4 x7 H2O: 22.50 g
- Stock solution IV of 1 ml/L: lron (lll) chloride, FeCl3 x 6 H2O: 0.25 g

Duration of test (contact time):

ca. 28 d

Details on study design:

TEST CONDITIONS
- Concentration of test substance in the test: 321 mg/L
- Concentration as DOC: 84.5 mg/L

TEST UNIT
1200 ml closed glass bottle containing a total volume of test solution of 600 ml; aerated with CO2-free air and fitted to gas'absorption bottles containing 120 ml of 0,5 M NaOH

TEST SYSTEM
- The activated sludge was used immediately after sampling from the treatment plant without adaptation. Prior to the test the sludge was washed twice with tap water. The test material was diluted with mineral salts medium to give a final DOC concentration of about 50 mg/L.
- For each test series the following number of test flasks was set up:
Test suspension (T) 2 replicates: containing activated sludge + test medium + lest substance
lnoculum blank (B), 2 replicas: containing activated sludge + test medium
Procedure control (R), 1 replicate: containing activated sludge + test medium + diethyleneglycol as ready biodegradable reference compound

The test vessels were stirred (100 r.p.m.) and aerated with synthetic CO2-free air . The air leaving the individual vessels was passed through gas-absorption bottles filled with NaOH.
- Oxygen concentration: > 6 mg/L.
- pH value. checked periodically and adjusted to pH 6.5-8.0 with NaOH or HCl, if necessary.
- Elimination of the test material: was followed by DOC determinations at regular intervals.

Reference substance:

diethylene glycol

Remarks:

Positive control

Parameter:

% degradation (CO2 evolution)

Value:

ca. 18

Sampling time:

28 d

Parameter:

other: Biodegradation

Value:

ca. 20

Sampling time:

28 d

Details on results:

Based on the data of the individual DOC determinations no significant elimination of DR23 was obserued after 28 days.
No significant elimination of the test substance due to adsorption to the activated sludge, on the glass surface or other physico-chemical processes was found as determined by means of DOC measurements 3 h after the start of the test.
The positive control, diethyleneglycol, showed 99 % biodegradation aller 14 days of incubation thus confirming suitability of inoculum and test conditions. The test was considered valid, since the degradation of the reference compound reached more than 70 % within 14 days of incubation.
Some biodegradation (18 %)of DR23 on CO, evolution and calculated as % was observed. The higher degradation value as compared to the DOC elimination cannot be explained. The extent of mineralization of the procedure control with diethyleneglycol was 94 % based on ThCO, (Table 2).
Based on these results DR23 is not inherently biodegradable under the conditions of the OECD guideline no, 302, since less than 20 % degradation was attained after 28 days of contact time.

Validity criteria fulfilled:

yes

Interpretation of results:

not inherently biodegradable

Conclusions:

Based on these results DR23 is not inherently biodegradable under the conditions of the OECD guideline no, 302, since less than 20 % degradation was attained after 28 days of contact time.

Executive summary:

The biodegradability of Direct Red 23 (DR23) exposed to activated sludge of a municipal sewage trealment plant was investigated under aerobic static conditions. Based on the data of the individual DOC determinations no significant elimination of DR23 was observed after 28 days. No significant elimination of the test substance due to adsorption to the activated sludge, on the glass sufface or other physico-chemical processes was found as determined by means of DOC measurements 3 h after the start of the test. The positive control, diethyleneglycol, showed 99 % biodegradation after 14 days of incubation thus confirming suitability of inoculum and test conditions. The test was considered valid, since the degradation of the reference compound reached more lhan 70 % within 14 days of incubation. Some biodegradation (18 %) of DR23, based on CO, evolution and calculated as % was observed. The higher degradation value as compared to the DOC elimination cannot be explained. The extent of mineralization of the procedure control with diethyleneglycol was 94 % based on ThCO2. Based on these results DR23 is not inherently biodegradable under the conditions of the OECD guideline no. 302, since less than 20 % degradation was attained after 28 days of contact time.

Reference 2

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

From 1 to 29 march 2007

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: No GLP.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Activated sfudge from the aeration tank of a municipal biological waste water treatment plant, not adapted, not pre-conditioned. 0.2 g/L dry matter in the final mixture.

Composition of the mineral salts medium:
- Stock solution I (pH 7.4) of 10 mg/L
Ammonium chloride, NH4Cl: 0.50 g
Di-sodium hydrogenphosphate, Na2H PO4 x 2 H2O: 33.40 g
Potassium dihydrogenphosphate, KH2PO4: 8.50 g
Di-potassium monohydrogenphosphate, K2HPO4: 21.75 g
- Stock solution II of 1 ml/L: Calcium chloride, anhydrous, CaCl2: 27.50 g
- Stock solution III of 1 ml/L: HzOMagnesium sulfate, MgSO4 x7 H2O: 22.50 g
- Stock solution IV of 1 ml/L: lron (lll) chloride, FeCl3 x 6 H2O: 0.25 g

Duration of test (contact time):

ca. 28 d

Initial conc.:

ca. 49.3 mg/L

Based on:

DOC

Initial conc.:

ca. 48.6 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Test unit: 1200 ml closed glass bottle containing a total volume of test solution of 800 ml; aerated with CO2-free air and fitted to gas-absorption bottles containing 125 mlof 0.13 M KOH
- Test Medium: Aerobic mineral salts medium prepared with double distilled water (conductivity: <1.5 pS/cm; DOC: <0.3 mg/l)
- Feed: None, test substance or procedure control as sole organic carbon sources

TEST SYSTEM
- The activated sludge was used immediately after sampling from the treatment plant without adaptation. Prior to the test the sludge was washed twice with tap water. The test material was diluted with mineral salts medium to give a final DOC concentration of about 50 mg/L.
- For each test series the following number of test flasks was set up:
Test suspension (T) 2 replicates: containing activated sludge + test medium + lest substance
lnoculum blank (B), 2 replicas: containing activated sludge + test medium
Procedure control (R), 1 replicate: containing activated sludge + test medium + diethyleneglycol as ready biodegradable reference compound

The test vessels were stirred (100 r.p.m.) and aerated with synthetic CO2-free air . The air leaving the individual vessels was passed through gas-absorption bottles filled with NaOH.
- Oxygen concentration: > 6 mg/L.
- pH value. checked periodically and adjusted to pH 6.5-8.0 with NaOH or HCl, if necessary.
- Elimination of the test material: was followed by DOC determinations at regular intervals.

SAMPLING
- Sampling frequency: first samples were analyzed at the beginning of and 3 h after starting the test

Reference substance:

diethylene glycol

Parameter:

% degradation (DOC removal)

Value:

ca. 7

Sampling time:

28 d

Details on results:

No significant elimination of the test substance due to adsorption to the activated sludge, on the glass surface or other physico-chemical processes was found as determined by means of DOC measurements 3 h after the start of the test.

Results with reference substance:

The positive control, diethyleneglycol, showed 99 % biodegradation alTer 14 days of incubation thus confirming suitability of inoculum and test conditions. The test was considered valid, since the degradation of the reference compound reached more than 70 % within 14 days of incubation.

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

No biodegradation of Direct Red 23based on CO2 evolution and calculated as % ThCOz was observed. The negative mineralization values even suggest some toxicity of the test material.

Executive summary:

The biodegradability of Direct REd 23 (DR23) exposed to activated sludge of a municipal sewage treatment plant was investigated under aerobic static conditions. Based on the data of the individual DOC determinations DR23 reached a biodegradation/bioelimination of 7 o/o afler 28 days. No significant elimination of the test substance due to adsorption to the activated sludge, on the glass sudace or other physico-chemical processes was found as determined by means of DOC measurements 3 h after the start of the test. The positive control, diethyleneglycol, showed 99 % biodegradation aller 14 days of incubation thus confirming suitability of inoculum and test conditions. The test was considered valid, since the degradation of the reference compound reached more than 70 % within 14 days of incubation. No biodegradation of DR23 based on CO2 evolution and calculated as % ThCO2 was observed. The negative mineralization values even suggest some loxicity of the test material. The extent of mineralization of the procedure controlwith diethyleneglycolwas 95 % based on ThCO2. Based on these data DR23 is not inherently biodegradable under the conditions of the OECD guideline no. 302, since less than 20 % degradation was attained after 28 days of contact time.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Principles of method if other than guideline:

Biodegradability estimates are based upon fragment constants that were developed using multiple linear or non-linear regression analyses, depending on the model.  A discussion of the methodology used to derived the linear and non-linear fragment constants in the first two models is presented in a journal article by Howard et al. (1992).

Details on inoculum:

Not applicable: estimation

Details on study design:

Not applicable: estimation

No readly biodegradable

Interpretation of results:

not readily biodegradable

Conclusions:

No readly biodegradable

Executive summary:

Estimated data using calculation software EpiSuite 4.1. Based suite of physical/chemical property and environmental fate estimation programs developed by the EPA’s Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC).

Substance: Direct Red 23 neutral form

Prediction: no readly biodegradable

Reference 4

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

other: expert judgement

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 A (Ready Biodegradability: DOC Die Away Test)

GLP compliance:

no

Inoculum or test system:

not specified

Remarks on result:

not readily biodegradable based on QSAR/QSPR prediction

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Based on estimation with EPIWIN and expert judgement evaluation, no ready biodegradability is expected.

Description of key information

Based on the evaluation of existing data end estimation by EPIWIN, the substance is considered not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

According to OECD guideline 302B, no biodegradation of Direct Red 23 (DR23) based on CO2 evolution and calculated as % ThCO2 was observed in the Clariant key study (Clariant, 2007), where less than 20% degradation was attained after 28 days of contact time. This outcome was confirmed by the result of the second Clariant key study of 2002 (Clariant, 2002).