2-[[4-[ethyl(2-hydroxyethyl)amino]phenyl]azo]-6-methoxy-3-methylbenzothiazolium chloride

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: screening test, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August 22 - September 04, 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1984;
according to DEV H 41- 1 Deutsche Einheitsverfahren,1980

Deviations:

yes

Remarks:

Mean of 2 determinations instead of 3

GLP compliance:

yes

Oxygen conditions:

other: not applicable; chemical oxidation

Remarks:

not applicable; chemical oxidation

Inoculum or test system:

other: not applicable; chemical oxidation

Remarks:

not applicable; chemical oxidation

Details on inoculum:

not applicable; chemical oxidation

Duration of test (contact time):

2 h

Initial conc.:

2.5 other: mg

Based on:

test mat.

Parameter followed for biodegradation estimation:

other: COD

Details on study design:

Not reported

Reference substance:

other: potassium hydrogen phthalate

Remarks:

Merck No. 4876

Remarks on result:

other: for results refer to the section BOD5/COD results

Key result

Parameter:

COD

Value:

1 384 mg O2/g test mat.

Remarks on result:

other: Result of COD measurement

Results with reference substance:

The COD of the reference substance poatssium hydrogen phthalat is: 199 mg O2/L (Criteria: 200 ± 8 mg O2/L)

Table 1: COD Analytical Data

Product	Sample weight [mg] E	Titration [ml]			N =	mg O2/g
		a	b	c
Blank		9.930 9.928 Ø = 9.929
Normality				10.123 10.119	0.1185 0.1185 Ø = 0.1185
Test item	2.5 2.5		6.287 6.271			1381 1387 Ø = 1384
Product	Stock solution [ml] E	Titration [ml]				mg O2/L
		a	b	c
Potassium hydrogen phthalate	20 20		5.723 5.724			199 199 Ø = 199

Validity criteria fulfilled:

not applicable

Remarks:

No validity criteria specified in method EU C.9 (1984)

Interpretation of results:

other: biodegradation can only be evaluated in connection with BOD measurements

Conclusions:

The chemical oxygen demand (COD) of the test substance in the test according to method EU C.9 is 1384 mg O2/g.

Executive summary:

The chemical oxygen demand (COD) of the test substance was investigated in a test according to method EU C.9.

2.5 mg of the test substance were chemically oxidised with potassium dichromate at 148 +/- 3 °C for 2h. The amount of unreacted potassium dichromate is determined by titration and the COD is calculated from this value. The COD of the test substance was determined to be 1384 mg O2/g under the conditions of this test.

Reference 2

Endpoint:

biodegradation in water: screening test, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

November 26 - December 02, 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

according to guideline

Guideline:

ISO 5815 (Water quality - Determination of Biochemical Oxygen Demand after 5 Days (BOD5) - Dilution and Seeding Method)

Version / remarks:

second edition 1989-08-01 (E)

Deviations:

yes

Remarks:

aerate over night after addition of the inoculum

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

other: seeding water of an urban waste water

Details on inoculum:

not reported

Duration of test (contact time):

5 d

Initial conc.:

806.9 mg/L

Based on:

test mat.

Initial conc.:

403.5 mg/L

Based on:

test mat.

Initial conc.:

201.7 mg/L

Based on:

test mat.

Initial conc.:

100.9 mg/L

Based on:

test mat.

Initial conc.:

50.4 mg/L

Based on:

test mat.

Initial conc.:

25.2 mg/L

Based on:

test mat.

Initial conc.:

12.6 mg/L

Based on:

test mat.

Initial conc.:

6.3 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Not reported

Reference substance:

other: D(+)-Glucose

Remarks:

Merck No. 8337

Reference substance:

other: L-Glutamic acid

Remarks:

Merck No. 291

Remarks on result:

other: for results refer to the section BOD5/COD results

Key result

Parameter:

BOD5

Value:

4 mg O2/g test mat.

Results with reference substance:

The BOD5 of glucose-glutamic acid is:
Ref. 1 = 190 mg O2/L
Ref. 2 = 185 mg O2/L
Ref. 3 = 200 mg O2/L

Table 1: BOD Analytical Data

Substance	Test concentration E [mg/L]	Start mg O2/L T0	End mg O2/L T5	Blank mg O2/L B1	mg O2/g BOD5
Test substance	806.9	8.6	4.5	0.5	4
		8.5	4.4	0.5	4
	403.5	8.5	6.2	0.5	4
		8.5	6.3	0.5	4
	201.7	8.6	7.9	0.5	1
		8.5	8.0	0.5	0
	100.9	8.6	8.4	0.5	0
		8.5	8.3	0.5	0
	50.4	8.6	8.4	0.5	0
		8.5	8.2	0.5	0
	25.2	8.5	8.4	0.5	0
		8.5	8.1	0.5	0
	12.6	8.5	8.3	0.5	0
		8.5	8.4	0.5	0
	6.3	8.5	8.4	0.5	0
		8.5	7.8	0.5	32
Reference	E [ml/L]
	20	8.6	4.3	0.5	190
	20	8.6	4.4	0.5	185
	20	8.6	4.1	0.5	200

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The biological oxygen demand after 5 days (BOD5) of the test substance is 4 mg O2/g.

Executive summary:

The biological oxygen demand after 5 days (BOD₅) of the test substance was investigated in a test according to ISO 5815 second edition 1989-08-01 (E).

The test substance was incubated with seeding water of an urban waste water at concetrations ranging between 806.9 and 6.3 mg/L for 5 days at 20 +/- 1 °C without supression of nitrification. Oyxgen measurements were conducted with an oxygen sensitive electrode (SYLAND).

The biological oxygen demand after 5 days (BOD₅) of the test substance is 4 mg O₂/g.

Description of key information

The chemical oxygen demand (COD) of the test substance was investigated in a test according to method EU C.9 and was determined to be 1384 mg O₂/g.

Measurements of the biological oxygen demand after 5 days (BOD₅) of the test substance were conducted according to ISO 5815 second edition 1989-08-01 (E) amd resulted in a value of 4 mg O₂/g.

The COD is a measure for the amount of organic compounds which can be chemically oxidised. The BOD₅ provides information on the amount of biodegradable organic matter.

The BOD₅ test is a traditional biodegradation test that is now replaced by the ready biodegradability tests and which should be therefore not be performed today for assessment of the ready biodegradability of substances. In case no other degradability data are available these older test data may however be used.

If substantial degradation occurs within a short time period, the situation may be compared with the criterion BOD₅/COD ≥ 0.5. In this case, a compound can be considered readily degradable (and hence rapidly degradable), if:

• the ultimate biodegradability exceeds 50% within 5 days and

• the ultimate degradation rate constant in the test system in this period is greater than 0.1 day-1 corresponding to a half -life of 7 days in the test system.

As the BOD₅/COD-ratio of the test substance is 0.003, the test substance can be considered not readily/rapidly biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed