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

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Report date:

1984

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

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

Method

Target gene:

Not reported.

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Additional strain / cell type characteristics:

not applicable

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1538

Additional strain / cell type characteristics:

not applicable

Species / strain 3

Species / strain / cell type:

E. coli WP2 uvr A

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

S9 Mix

Test concentrations with justification for top dose:

10, 50, 100, 500, 1000 and 5000 µg/plate

Vehicle / solvent:

DMSO was used as vehicle.

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

sodium azide

Controls 2

Positive control substance:

9-aminoacridine

Controls 3

Positive control substance:

2-nitrofluorene

Controls 4

Positive control substance:

2-acetylaminofluorene

Details on test system and experimental conditions:

The test was carried out using the poured plate method. The test was performed with and without metabolic activiation using S9 Mix. Bacterial suspension (0.1 mL), test solution (0.1 mL) and sodium phosphonate buffer or S9 Mix (0.5 mL) was added to each plate with top agar (2.0 mL). The plates were then incubated for 48 h at 37 °C.

Evaluation criteria:

The number of revertant colonies were then counted.

Statistics:

No statistical methods were reported.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 3

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

The test substance showed no evidence of mutagenic activity when tested in bacterial systems.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Mean Revertant Colonies

Material	Test concentration (µg/plate)	With or without S9 mix	Reverse mutation (number of colonies)
			Base pair exchange type			Frame shift type
			TA100	TA1535	WP2	TA98	TA1537	TA1538
Solvent control		-	110	16	24	24	14	16
Test compound	10	-	100	12	30	19	9	16
	50	-	93	16	29	14	19	10
	100	-	86	12	26	20	13	12
	500	-	94	6	28	19	11	17
	1000	-	89	11	30	18	9	12
	5000	-	108	10	22	20	7	8
Solvent control		+	84	10	28	20	18	13
Test compound	10	+	89	4	30	17	22	14
	50	+	92	8	20	23	14	20
	100	+	92	4	26	20	10	12
	500	+	100	6	28	24	14	14
	1000	+	100	6	28	21	16	15
	5000	+	98	6	23	18	4	10

Reported value is the mean of duplicate plates
- = absence, + = presence

Positive controls	Not requiring S9 Mix	Name	AF-2	NaN3	AF-2	AF-2	9AA	2NF
		Concentration (µg/plate)	0.01	0.5	0.04	0.1	80	2
		Number of colonies/plate	499	362	550	525	>1000	806
	Requiring S9 Mix	Name	AF-2	NaN3	AF-2	AF-2	9AA	2NF
		Concentration (µg/plate)	0.5	2	80	0.5	2	0.5
		Number of colonies/plate	486	241	>1000	330	213	558

AF-2 = 2 -aminofluorene; NaN3 = sodium azide; 9AA = 9 -aminoacridine; 2NF = 2 -nitrofluorene

(Author note: the results reported for the positive controls 9AA (without S9 mix) and AF-2 (with S9 mix) at 80 µg/plate appear in the study report as '1000<', the author has assumed that this was intended to state >1000 as shown in the table above)

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

The study report describes a valid guideline study. No information about GLP compliance is available. It was concluded that the test material showed no evidence of mutagenic activity when tested in bacterial test systems.

Executive summary:

An Ames metabolic activation test to assess the potential mutagenic effect of the test material was conducted using a similar procedure to that described in the current OECD Guideline 471. The test material (CAS No. 73984 -93 -7) was tested in 5 strains of Salmonella typhimurium and one strain of Escherichia coli. The test material was dissolved in dimethyl sulphoxide and was tested at 10, 50, 100, 500, 1000 and 5000 µg/plate using the poured plate method, with and without metabolic activation. Solvent controls and positive controls were included in the test. It was concluded that the test material showed no evidence of mutagenic activity when tested in bacterial test systems.