Reactive Orange 16

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:

weight of evidence

Study period:

From February 8,1990 to February 21,1990

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant with international guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Provenienza:Hoechst wastewater biological treatment plant
- Concentration of sludge:10 g/L, 1020 mg/L of dry weight

Duration of test (contact time):

ca. 28 d

Initial conc.:

ca. 44 other: mg C/L

Based on:

DOC

Parameter followed for biodegradation estimation:

other: COD

Details on study design:

TEST CONDITIONS
- Composition of medium:
- Additional substrate:
- Solubilising agent (type and concentration if used):
- Test temperature:22°C
- pH:7.3
- pH adjusted: yes with NaOH
- CEC (meq/100 g):
- Aeration of dilution water:
- Suspended solids concentration:
- Continuous darkness: yes/no
- Other:

TEST SYSTEM
- Culturing apparatus:
- Number of culture flasks/concentration:
- Method used to create aerobic conditions:
- Method used to create anaerobic conditions:
- Measuring equipment:
- Test performed in closed vessels due to significant volatility of test substance:
- Test performed in open system:
- Details of trap for CO2 and volatile organics if used:
- Other:

SAMPLING
- Sampling frequency:
- Sampling method:
- Sterility check if applicable:
- Sample storage before analysis:
- Other:

CONTROL AND BLANK SYSTEM
- Inoculum blank:
- Abiotic sterile control:
- Toxicity control:
- Other:

STATISTICAL METHODS:

Parameter:

other: COD

Value:

ca. 4

Sampling time:

28 d

Details on results:

no data

Results with reference substance:

no reference substance

Biodegradation within 28 days

time	elimination	biodegradation	mean
3h	0%	0%	< 10%
7 days	2%	2%
14 days	-8%	-8%
21 days	-2%	-2%
28 days	4%	4%

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

After 29 days of treatment the substance was degraded less than 10%. (~4%)

Executive summary:

Reactive orange 16 was tested by OECD 302B (Zhan-Wellens test). After 29 days of treatment the substance was degraded less than 10%. (~4%)

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

other: read across from supporting substance

Adequacy of study:

weight of evidence

Study period:

Since November 18,1985 to December 17,1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP compliant with international guideline

Qualifier:

according to guideline

Guideline:

other: EEC-Directive 79/831, Part C: Methods for the Determination of Ecotoxicity,

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge:municipal wastewater treatment plant, F-Sindlingen

Duration of test (contact time):

ca. 29 d

Initial conc.:

ca. 58 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Test vessel: Erlenmeyer flasks 20 ml
- Test temperature :21°C
- pH:7.1
- pH adjusted: no
-Other:
mother solution: 5 g/L in distilled water

Reference substance:

other: hydroquinone

Parameter:

% degradation (DOC removal)

Value:

< 10

Sampling time:

29 d

Results with reference substance:

hydroquinone


2.0 in deionized water


4.9, was used with NaOH to pH 7.1. DOC: 1275 mg C / l

Inoculum and reaction medium of instruction (No. 1.6.1.2 and 1.6.4)

sempling time	control DOC mg/L	test item DOC, mg/L	test item degradation %	positive control DOC mg/L	positive control DOC degradation %
3h	2.9	18.9	5.5	16.6	17
ld	2.1	18.2	9	17.7	11.6
3 d	2	19	5	17	15
7d	2	19	5	5.4	73
10 d	2.1	21.7	0	6.9	65.5
17 d	3.7	21.2	0	5.7	71,5
21 d	0.9	30**	-	5.5	72.5
24 d	1.6	22.4	0	5.8	72,5
28 d	2.6	21.4	0	5.4	71
29 d	1.9	19.1	4.5	5.4	73

** outlier

Validity criteria fulfilled:

yes

Interpretation of results:

other: not ready biodegradable

Conclusions:

After 29 days of treatment the substance was degraded less than 10%.

Executive summary:

The similar substance 1 was tested by OECD 301E screening test. The substance it not ready biodegradable.

Description of key information

OECD 301E, similar substance 1, Less than 10%  in 28 days

OECD302B, COD ca 4% in 28 days

OECD203B enhanced, similar substance 2, not inherently

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The target substance was tested following OECD 301E screening test for ready biodegradation with a final results < 10% indicating that the substance is  not readily biodegradable

Similar substance 1 was tested following OECD 302B for inherently biodegradation. At the end of the test period no biodegradation was observed.  therefore Reactive Orange 16 is not classified as inherently biodegradable.Also similar substance 2 showed no biodegradation following enhanced inherently biodegradation test. Simulation test on water and sediment as per OECD309 is  therefore submitted as to completely assess the biodegradation behaviour of the substance.