Reaction products of 7-amino-4-hydroxynaphthalene-2-sulfonic acid reacted with 2-((1,3,5-triazin-2-yl)amino)ethan-1-ol, coupled with diazotised 3-amino-4-hydroxybenzenesulfonic acid, subsequently coupled with diazotised 2-amino-5-methoxybenzenesulfonic acid, chelated with copper, sodium salt

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 1991-04-17 to 1991-05-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1984

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Type of inoculum: Activated sludge bacteria.
- Source of inoculum: The aeration stage of the Severn Trent PLc Sewage treatment plant at Belper, Derbyshire (U.K), treating predominantly domestic sewage.
- Data of collection: 1991-04-17
- Preparation: The sample was allowed to settle and the supernatant filtered through Whatman GFA filter paper (first 200 mL discarded)

Duration of test (contact time):

> 0 - <= 28 d

Initial conc.:

ca. 2 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

DOC removal

Remarks:

(DOC for each medium were determined, in duplicate at 0.5, 15 and 28 days by means of a yellow Springs 800 probe).

Details on study design:

TEST CONDITIONS
- Composition of medium: Standard nutrient medium according to OECD guideline
- Additional substrate: No
- Solubilising agent: No
- Test temperature: 21 °C
- pH adjusted: no
- Aeration of dilution water: yes
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 250-300 mL BOD bottles (darkened glass) with ground glass stoppers
- Number of culture flasks/concentration: 2 flasks/concentration
Test concentrations:
(a) Non-inoculated dilution water: 2 flasks
(b) Inoculated dilution water: 2 flasks
(c) 2 mg/L test material: 2 flasks
(d) 3 mg/L sodium benzoate: 2 flasks
Test media b, c and d were inoculated with activated sludge filtrate at the rate of 1 drop of Inoculum per litre.
Procedure: BOD bottles were filled, by siphon and firmly stoppered to exclude all air bubbles. Sufficient bottles were prepared to allow single oxygen determination per bottle to be made at 0, 5, 15 and 28 days for each test medium (duplicate bottles at each sampling time).
Bottles were incubated in a water bath at 21°C for 0, 5, 15 or 28 days as appropriate.
- Measuring equipment: Dissolved oxygen concentration for each test medium were determined, in duplicate, at 0, 5, 15 and 28 days by mean of a yellow Springs 800 Probe (Model 800)
- Test performed in open system: no

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: no
- Toxicity control: no
- Positive control: Performed with the reference substance sodium benzoate

Reference substance:

benzoic acid, sodium salt

Remarks:

3 mg/L sodium benzoate

Preliminary study:

Not performed.

Test performance:

The validity criteria were fulfilled.

Key result

Parameter:

% degradation (DOC removal)

Remarks:

only 6% degradation with 28 days

Value:

ca. 6

Sampling time:

28 d

Remarks on result:

other: Observations: Dissolved oxygen concentrations for each test medium were determined, in duplicate, at 0, 5, 15 and 28 days by means of a Yellow Springs BOD Probe.

Details on results:

Kayarus Supra Rubine BLN attained only 6% degradation with 28 days therefore is considered to be not readily biodegradable.

Results with reference substance:

Sodium benzoate attained 103% degradation within 28 days.

Table 1: Mean Oxygen Depletion and percentage Biodegradation Values.

Test Series	Day
	5	15	28
(a) Dilution water without inoculum O2 depletion in (mg O2/L) % degradation	0.025	0.075	0.175
(b) Dilution water with inoculum O2 depletion in (mg O2/L) % degradation	0.075	0.175	0.200
(c) Kayarus Supra Rubine BLN (2mg/L) with inoculum O2 depletion in (mg O2/L) % degradation	0.125 4	0.100 4	0.175 6
(d) Standard material, Sodium benzoate (3mg/L) with inoculum O2 depletion in (mg O2/L) % degradation	4.575	4.750	5.150
	91	95	103

 

Closed bottle test according to OECD Guideline No. 301 referenced as Method C.6 of Commission Directive 84/449/EEC

 

Duration: 28 days

 

Temperature: 21°C

 

Test concentration: 2 mg/L

 

Oxygen depletion (28 days): 0.175 mg O₂/L

 

Theoretical oxygen demand (ThOD): 1.40 mg O₂/L

 

Percentage Biodegradation (28 days): 6 %

 

Method of Preparation: direct dispersion in culture medium

Results:

Kayarus Supra Rubine BLN attained only 6% degradation with 28 days and so cannot, therefore, be considered as ready biodegradable.

Sodium benzoate attained 103% degradation within 28 days.

Oxygen depletions in the inoculated and non-Inoculated control series were within the prescribed limits*.

 

* Non-inoculated control:

 < 0.3 mg O₂/L after 5 days

 < 0.4 mg O₂/L after 28 days
Inoculated control:

 < 0.5 mg O₂/L after 5 days
< 0.6 mg O₂/L after 28 days

 

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Kayarus Supra Rubine BLN attained only 6% degradation with 28 days therefore is considered to be not readily biodegradable.

Executive summary:

A study on biodegradation was performed according to OECD 301 D under GLP conditions. Dissolved oxygen measurements for the test and standard material solutions, together with the inoculated and non-inoculated blank controls, at 0, 5, 15 and 28 days were assessed. Sodium benzoate attained 103% degradation within 28 days. The validity criteria were met. Kayarus Supra Rubine BLN attained only 6% degradation with 28 days therefore is considered to be not readily biodegradable.

Description of key information

The read across substance Kayarus Supra Rubine BLN attained only 6% degradation with 28 days, therefore the test substance is considered to be as not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater

Additional information

A study on biodegradation was performed according to OECD 301 D under GLP conditions. Dissolved oxygen measurements for the test and standard material solutions, together with the inoculated and non-inoculated blank controls, at 0, 5, 15 and 28 days were assessed. Sodium benzoate attained 103% degradation within 28 days. The validity criteria were met. The read across substance Kayarus Supra Rubine BLN attained only 6% degradation with 28 days therefore is considered to be not readily biodegradable.