Dodecane-1-thiol

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

Study period:

1983-05-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study is classified as reliable without restriction because it is GLP compliant and comparable to OECD guideline 471 and OPPTS 870.5100.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Report date:

1983

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Principles of method if other than guideline:

Method: other: Simialr to OPPTS 870.5100

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Dodecane-1-thiol (CAS # 112-55-0)

IUPAC Name:

Dodecane-1-thiol (CAS # 112-55-0)

Details on test material:

dodecane-1-thiol
purity: Assumed 100%

Method

Species / strain

Species / strain / cell type:

other: Strains 1535, 1537, 1538, TA98, TA100

Metabolic activation:

with and without

Test concentrations with justification for top dose:

10,000, 3333, 1111, 370.4, 123.5 ug/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO

Controls

Untreated negative controls:

yes

Remarks:

Bacteria only, S-9 Fraction

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Remarks:

MNNG, 9-AA, 2-NF

Details on test system and experimental conditions:

IUCLID4 Type: Salmonella typhimurium reverse mutation assay

Evaluation criteria:

Positive response requires a minimum two-fold increase in revertants compared with solvent control over three dose levels with appropriate response in positive and negative controls.

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA98, 100, 1535, 1537, and 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Additional information on results:

No increase in reversion rates occurred over the dose range tested.

Remarks on result:

other: other: TA98, 100, 1535, 1537, and 1538

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Without activation:

Treatment	Dose level (µg/mL	No. of cells analyzed	Total no. of SCE’s	No. of SCE’s/cell	P value	Fold inc. in SCE’s/cell	No. chromosomes analyzed	No./ SEC’s/chromosome	P Value	Fold inc. in SCE’s/chromosome
Media control	-	50	456	9.10	-	-	997	.46	-	-
DMSO	-	50	437	8.74	-	-	1002	.44	-	-
EMS	400	50	998	19.96	.0000	2.2	997	1.00	.0000	2.2
n-Dodecyl mercaptan	10	50	408	8.16	.13	.9	986	.41	.19	.9
	3.3	50	387	7.74	.03	.9	968	.39	.05	.9
	1.0	50	412	8.24	.16	.9	1006	.41	.15	.9
	.3	50	458	9.36	.13	1.1	998	.47	.10	1.1
	.2	50	484	9.68	.05	1.1	983	.50	.02	1.1

With activation:

Treatment	Dose level (µg/mL	No. of cells analyzed	Total no. of SCE’s	No. of SCE’s/cell	P value	Fold inc. in SCE’s/cell	No. chromosomes analyzed	No./ SEC’s/chromosome	P Value	Fold inc. in SCE’s/chromosome
Media control	-	50	476	9.52	-	-	998	.48	-	-
DMSO	-	50	449	8.98	-	-	995	.45	-	-
CP	1.4	50	1122	22.44	.0000	2.4	997	1.13	.0000	2.4
n-Dodecyl mercaptan	10	50	423	8.46	.21	.9	984	.43	.23	1.0
	3.3	50	501	10.02	.03	1.1	985	.51	.02	1.1
	1.0	50	455	9.30	.28	1.0	1000	.46	.32	1.0
	.3	50	443	8.86	.42	1.0	997	.45	.45	1.0
	.1	50	461	9.22	.34	1.0	993	.47	.31	1.1

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

Under these conditions, n-dodecyl mercaptan did not exhibit a positive response and is considered not to be mutagenic in this test system.

Executive summary:

In a bacterial reverse mutation assay, strains 1535, 1537, 1538, TA98, and TA100 cultured in vitro were exposed to dodecane-1-thiol in DMSO at concentrations of 123.5, 374.4, 1111, 3333, 10,000 μg/mL in the presence and absence of S-9 mammalian metabolic activation.

 

Dodecane-1-thiol was tested up to 10,000 μg/mL, as this represented the limit of solubility. Exposure to five graded doses of dodecane-1-thiol in the presence and in the absence of metabolic activation did not increase the reversion to histidine prototrophy of S. typhimurium strains 1535, 1537, 1538, TA98 or TA100. Under these conditions the experimental dodecane-1-thiol did not exhibit a positive response and is not considered to be mutagenic in this test system. The positive controls did induce the appropriate response. 

 

This study received a Klimisch score of 1 and is classified as reliable without restriction because it is GLP compliant and comparable to the guideline study.