1,3,4-Thiadiazole-2(3H)-thione, 5-(tert-dodecyldithio)-

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:

July to September 1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Source of activated sludge not reported, pH and oxygen uptake values not reported. Also no mention of GLP in report.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Report date:

1984

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Deviations:

yes

Remarks:

Source of activated sludge not reported, pH and oxygen uptake values not reported. Also no mention of GLP in report.

Principles of method if other than guideline:

Source of activated sludge not reported, pH and oxygen uptake values not reported

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

1,3,4-Thiadiazole-2(3H)-thione, 5-(tert-dodecyldithio)-

EC Number:

813-543-0

Cas Number:

73984-93-7

Molecular formula:

C14H26N2S4

IUPAC Name:

1,3,4-Thiadiazole-2(3H)-thione, 5-(tert-dodecyldithio)-

Test material form:

liquid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): not reported
- Concentration of sludge: 30 mg/L

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Test temperature: 25±1°C
- Suspended solids concentration: 30 mg/L

TEST SYSTEM
- Measuring equipment: BOD meter

SAMPLING
- Sampling frequency: 7, 14 and 28 days

CONTROL AND BLANK SYSTEM
- Inoculum blank: included

Reference substance

Reference substance:

not specified

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Any other information on results incl. tables

Table 1 Percent Biodegradation

	7 days		14 days		28 days
	BOD (mg)	Biodeg. (%)	BOD (mg)	Biodeg. (%)	BOD (mg)	Biodeg. (%)
Inoculum control	1.6	-	3.3	-	8.0	-
Test chemical*	1.0	0	2.0	0	3.0	0
Test chemical*	0	0	3.0	0	4.2	0

* = The reported values are the mean value for duplicate samples

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test material is not readily biodegradable.

Executive summary:

The ready biodegradability of the test substance (CAS No. 50530 -43 -3) was evaluated using a similar procedure to that described in the current OECD Guideline 301C.  Standard activated sludge was used as inoculum and the initial concentration of test substance was 100 mg/L. After an incubation period of 28 days at 25±1°C there was no ready biodegradability observed during the test.