2,6-Diamino-4,5,6,7-tetrahydrobenzothiazole

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20 december 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted in GLP compliance and in accordance with several internationally established guidelines (OECD, EEC, EPA, see below).

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

SND 919 Precursor 2 (SND 855 BS)

IUPAC Name:

SND 919 Precursor 2 (SND 855 BS)

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): SND 919 Precursor 2 (SND 855 BS); SND 919 Precursor 2 (SND 855)
- Molecular formula (if other than submission substance): C7H11N3S
- Molecular weight (if other than submission substance): 169.25
- Structural formula attached as image file (if other than submission substance): see Reference substance
- CAS number: 104617-49-4
- Physical state: grey solid powder
- Analytical purity: 98.0%
- Purity test date: 17 october 2004
- Lot/batch No.: 14
- Expiration date of the lot/batch: october 2005
- Storage condition of test material: at room temperature, dark and dry

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

not specified

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): STP for domestic sewage in Veszprem, Hungary

The activated sludge used for this study was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was re-suspended in isotonic saline solution and again centrifuged. This procedure was repeated twice. An aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge to its dry weight was determined. Based on this ratio, calculated aliquots of washed sludge suspension, corresponding to 4 g dry material per litre were mixed with test water (

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

2 mg/L

Based on:

ThOD/L

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: grade salts were added to deionised water to give stock solutions. Stock solutions were diluted in deionised water, aerated for 20 minutes and allowed to stand for 20 hrs at the test temperature. Dissolved oxygen concentration was about 9.0 mg/L prior to starting the test.
- Test temperature: 19.7 - 20.6 °C
- pH: 7.55 (at the start of the test)
- pH adjusted: no
- Aeration of dilution water: yes (see above)


TEST SYSTEM
- Culturing apparatus: BOD 300 mL bottles
- Number of culture flasks/concentration: Each 16 (+2 reserve) bottles containing: a) the test item and inoculum, b) the reference item and inoculum (positive control), c) only inoculum (inoculum control) and d) test item, reference item and inoculum (toxicity control).
- Method used to create aerobic conditions: inoculum and medium solutions were sufficiently aerated prior to the start of the test.
- Measuring equipment: self-stirring O2 electrode
- Test performed in closed vessels: yes
- Details of trap for CO2 and volatile organics if used: not used


SAMPLING
- Sampling frequency: oxygen was measured at days 0, 2, 5, 7, 12, 14, 21 and 28 after the start of the test.
- Sampling method: no sampling was performed for oxygen analysis, the oxygen concentrations were measured with an oxygen meter with a stirring O2 electrode.
- Sterility check if applicable: no
- Sample storage before analysis: no
- Other: Nitrite and nitrate concentrations were measured by colorimetric method

CONTROL AND BLANK SYST EM
- Inoculum blank: yes
- Abiotic sterile control: no
- Toxicity control: yes
- Other: see above for details

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

13

Sampling time:

28 d

Details on results:

The residual oxygen concentration in the test flasks did not drop below 0.5 mg O2/L at any time.

BOD5 / COD results

BOD5 / COD

Parameter:

BOD5

Value:

mg O2/g test mat.

Results with reference substance:

The percentage of degradation of the reference substance item reached the passt level for ready biodegradability (> 60%) within 14 days.
The oxygen consumption in the inoculum control did not exceed 1.5 mg/L after 28 days.

Any other information on results incl. tables

Dissolved oxygen concentrations at different time intervals during the exposure period of 28 days

Treatment	Concentration [mg/L]	Flask No.	mg O2/L after n days of exposure
			0	2	5	7	12	14	21	28
Test item	2.0	1a	9.0	8.6	8.1	7.8	7.5	7.3	7.1	7.0
		1b	9.0	8.5	8.2	7.8	7.5	7.4	7.2	7.1
		mean	9.0	8.55	8.15	7.80	7.50	7.35	7.15	7.05
Reference item	7.6	2a	9.0	5.1	3.6	3.1	2.8	2.6	2.5	2.1
		2b	8.9	5.0	3.6	3.1	2.9	2.6	2.4	2.2
		mean	8.95	5.05	3.60	3.10	2.85	2.60	2.45	2.15
Inoculum control	-	3a	9.0	8.8	8.6	8.3	8.1	8.0	7.8	7.7
		3b	8.9	8.7	8.5	8.2	8.0	8.0	7.9	7.8
		mean	8.95	8.75	8.55	8.25	8.05	8.00	7.85	7.75
Toxicity control	Test item: 2.0Reference item: 7.6	4a	8.9	5.2	3.6	3.1	2.7	2.3	2.1	1.8
		4b	8.9	5.0	3.5	3.2	2.6	2.3	2.0	1.7
		mean	8.90	5.10	3.55	3.15	2.65	2.3	2.05	1.75

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: not ready biodegradable

Conclusions:

Under the test conditions the percentage biodegradation of SND 919 Precursor 2 (SND 855 BS) reached a mean of 13 % after 28 days based on ThODNO3. The test item can therefore be considered to be not ready biodegradable.