Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Toxicological information

Genetic toxicity: in vitro

Currently viewing:

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
15 May 2012 - 09 July 2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Compliant to GLP and testing guidelines; adequate consistence between data, comments and conclusions.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Reference substance name:
tetramethylthiuram monosulfide
IUPAC Name:
tetramethylthiuram monosulfide
Constituent 2
Chemical structure
Reference substance name:
Tetramethylthiuram monosulphide
EC Number:
202-605-7
EC Name:
Tetramethylthiuram monosulphide
Cas Number:
97-74-5
Molecular formula:
C6H12N2S3
IUPAC Name:
N,N-dimethyl[(dimethylcarbamothioyl)sulfanyl]carbothioamide
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
- Name of test material: Tetramethylthiuram monosulfide
- Physical state: yellow powder
- CAS number: 97-74-5
- Lot/batch No.: 12012103161
- Analytical purity: 99.8%
- Expiry date: 31 January 2013
- Storage conditions: at room temperature protected from humidity and heat.

Method

Target gene:
Histidine operon
Species / strain
Species / strain / cell type:
S. typhimurium, other: TA 1535, TA 1537, TA 98, TA100 and TA 102
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
rat liver S9 mix
Test concentrations with justification for top dose:
Without S9: 156.3, 312.5, 625, 1250, 2500 and 5000 µg/plate or both mutagenicity experiments.
With S9 : 156.3, 312.5, 625, 1250, 2500 and 5000 µg/plate for both mutagenicity experiments.
Vehicle / solvent:
- Vehicle used: dimethylsulfoxide
- Justification for choice: test item was soluble in the vehicle at 100 mg/mL.
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: sodium azide, 9-aminoacridine, 2-nitrofluorene, mitomycin C (-S9 mix); 2-anthramine, benzo(a)pyrene (+S9 mix)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar

DURATION
Both experiments were performed according to the direct plate incorporation method except for the second test with S9 mix, which was performed according to the pre-incubation method (60 minutes, 37°C).
Five strains of bacteria Salmonella typhimurium: TA 1535, TA 1537, TA 98, TA 100 and TA 102 were used. Each strain was exposed to at least five dose-levels of the test item (three plates/dose level). After 48 to 72 hours of incubation at 37°C, the revertant colonies were scored.

DETERMINATION OF CYTOTOXICITY
- Method: decrease in number of revertant colonies and/or thinning of the bacterial lawn
Evaluation criteria:
A reproducible 2-fold increase (for the TA 98, TA 100 and TA 102 strains) or 3-fold increase (for the TA 1535 and TA 1537 strains) in the number of revertants compared with the vehicle controls, in any strain at any dose-level and/or evidence of a dose-relationship was considered as a positive result. Reference to historical data, or other considerations of biological relevance may also be taken into account.
Statistics:
no

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
True negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
True negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
at 5000 µg/ml (with S9) only
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
True negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
True negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
True negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
Experiments without S9 mix : The selected treatment-levels for both mutagenicity experiments were: 156.3, 312.5, 625, 1250, 2500 and 5000 µg/plate. No precipitate was observed in the Petri plates when scoring the revertants at any dose-levels, in any experiments. No noteworthy toxicity (decrease in the number of revertants or thinning of the bacterial lawn) was noted at any dose-levels towards the five strains used, in any experiments. Noteworthy increases in the number of revertants were noted in the TA 100 strain in the first and second experiments. These increases exceeded the threshold of 2-fold the vehicle control (up to 2.3-fold), were dose-related and reproducible. They were therefore considered as biologically significant. The test item did not induce any other noteworthy or biologically significant increases in the number of revertants in the other tested strains

Experiments with S9 mix : The selected treatment-levels were: 156.3, 312.5, 625, 1250, 2500 and 5000 µg/plate for both mutagenicity experiments.
No precipitate was observed in the Petri plates when scoring the revertants at any dose-levels, in any experiments. A strong toxicity (thinning of the bacterial lawn) was noted at 5000 µg/plate towards the TA 1537 strain, in the first experiment only. No noteworthy toxicity (decrease in the number of revertants or thinning of the bacterial lawn) was noted towards the other strains used, in any experiments. Increases in the number of revertants were noted in the TA 1535 strain in the first and second experiments. These increases exceeded the threshold of 3-fold the vehicle control (up to 3.2-fold and 6.7-fold the vehicle control in the first and second experiments, respectively). Even if they were not dose-related, the increases observed in the first assay were reproduced in the second experiment performed under the pre-incubation method. Moreover, the corresponding means and individual revertant colony counts were above the historical data range of the vehicle control. Consequently, these increases were considered to be biologically significant. Using the direct plate incorporation method (first experiment), increases in the number of revertants were noted in the TA 100 strain at dose-levels = 1250 µg/plate. These increases did not reach the threshold of 2 -fold the vehicle control but the corresponding means and individual revertant colony counts were above the historical data range of the vehicle control.
Increases in the number of revertants were also noted in the second experiment performed using the pre-incubation method. These increases exceeded the threshold of 2-fold the vehicle control at all tested dose-levels (up to 3.7 -fold). Moreover, the corresponding means and individual revertant colony counts were above the historical data range of the vehicle control. Consequently, these increases were considered to be biologically significant. The test item did not induce any other noteworthy or biologically significant increases in the number of revertants in the other tested strains.

Applicant's summary and conclusion

Conclusions:
The test item, Tetramethylthiuram monosulfide, showed mutagenic activity in the bacterial reverse mutation test with Salmonella typhimurium in the absence and in the presence of a metabolic activation system.
Executive summary:

The objective of this study was to evaluate the potential of the test item to induce reverse mutation in Salmonella typhimurium.

The study was performed according to the international guidelines (OECD No. 471 and Council Regulation No. 440/2008 of 30 May 2008, Part B13/14) and in compliance with the principles of Good Laboratory Practice.

 

A preliminary toxicity test was performed to define the dose-levels of Tetramethylthiuram monosulfide to be used for the mutagenicity study. The test item was then tested in two independent experiments, with and without a metabolic activation system, the S9 mix, prepared from a liver post-mitochondrial fraction (S9 fraction) of rats induced with Aroclor 1254.

 

Both experiments were performed according to the direct plate incorporation method except for the second test with S9 mix, which was performed according to the pre-incubation method (60 minutes, 37°C). Five strains of bacteria Salmonella typhimurium: TA 1535, TA 1537, TA 98, TA 100 and TA 102 were used. Each strain was exposed to at least five dose-levels of the test item (three plates/dose-level). After 48 to 72 hours of incubation at 37°C, the revertant colonies were scored. The evaluation of the toxicity was performed on the basis of the observation of the decrease in the number of revertant colonies and/or a thinning of the bacterial lawn.

The test item Tetramethylthiuram monosulfide was dissolved in dimethylsulfoxide (DMSO).

 

Experiments without S9 mix : The selected treatment-levels for both mutagenicity experiments were: 156.3, 312.5, 625, 1250, 2500 and 5000 µg/plate. No precipitate was observed in the Petri plates when scoring the revertants at any dose-levels, in any experiments. No noteworthy toxicity (decrease in the number of revertants or thinning of the bacterial lawn) was noted at any dose-levels towards the five strains used, in any experiments. Noteworthy increases in the number of revertants were noted in the TA 100 strain in the first and second experiments. These increases exceeded the threshold of 2-fold the vehicle control (up to 2.3-fold), were dose-related and reproducible. They were therefore considered as biologically significant. The test item did not induce any other noteworthy or biologically significant increases in the number of revertants in the other tested strains


Experiments with S9 mix : The selected treatment-levels were: 156.3, 312.5, 625, 1250, 2500 and 5000 µg/plate for both mutagenicity experiments.

No precipitate was observed in the Petri plates when scoring the revertants at any dose-levels, in any experiments. A strong toxicity (thinning of the bacterial lawn) was noted at 5000 µg/plate towards the TA 1537 strain, in the first experiment only. No noteworthy toxicity (decrease in the number of revertants or thinning of the bacterial lawn) was noted towards the other strains used, in any experiments. Increases in the number of revertants were noted in the TA 1535 strain in the first and second experiments. These increases exceeded the threshold of 3-fold the vehicle control (up to 3.2-fold and 6.7-fold the vehicle control in the first and second experiments, respectively). Even if they were not dose-related, the increases observed in the first assay were reproduced in the second experiment performed under the pre-incubation method. Moreover, the corresponding means and individual revertant colony counts were above the historical data range of the vehicle control. Consequently, these increases were considered to be biologically significant. Using the direct plate incorporation method (first experiment), increases in the number of revertants were noted in the TA 100 strain at dose-levels = 1250 µg/plate. These increases did not reach the threshold of 2 -fold the vehicle control but the corresponding means and individual revertant colony counts were above the historical data range of the vehicle control.

Increases in the number of revertants were also noted in the second experiment performed using the pre-incubation method. These increases exceeded the threshold of 2-fold the vehicle control at all tested dose-levels (up to 3.7 -fold). Moreover, the corresponding means and individual revertant colony counts were above the historical data range of the vehicle control. Consequently, these increases were considered to be biologically significant. The test item did not induce any other noteworthy or biologically significant increases in the number of revertants in the other tested strains.

 

The test item showed mutagenic activity in the bacterial reverse mutation test with Salmonella typhimurium in the absence and in the presence of a metabolic activation system.