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Diss Factsheets
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EC number: - | CAS number: 75045-07-7
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Genetic toxicity: in vitro
Administrative data
- Endpoint:
- in vitro gene mutation study in bacteria
- Remarks:
- Type of genotoxicity: gene mutation
- Type of information:
- migrated information: read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- key study
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: GLP guideline study
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 2 012
- Report date:
- 2012
Materials and methods
Test guideline
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 471 (Bacterial Reverse Mutation Assay)
- Principles of method if other than guideline:
- The study was performed to investigate the potential of 1,3-Dihydro-4(or5)-methyl-2Hbenzimidazole-2-thione to induce gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using the Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100, and TA 102.
- GLP compliance:
- yes
- Type of assay:
- bacterial reverse mutation assay
Test material
- Reference substance name:
- 1,3-dihydro-4(or 5)-methyl-2H-benzimidazole-2-thione
- EC Number:
- 258-904-8
- EC Name:
- 1,3-dihydro-4(or 5)-methyl-2H-benzimidazole-2-thione
- Cas Number:
- 53988-10-6
- Molecular formula:
- C8H8N2S
- IUPAC Name:
- 1,3-dihydro-4(or 5)-methyl-2H-benzimidazole-2-thione
- Details on test material:
- Identity: 1,3-Dihydro-4(or 5)-methyl-2H-benzimidazole-2-thione
Purity: > 97 % (dose calculation not adjusted to purity)
Constituent 1
Method
Species / strain
- Species / strain / cell type:
- S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102
- Additional strain / cell type characteristics:
- other: due to the "deep rough" (rfa-) mutation they possess a faulty lipopolysaccharide envelope which enables substances to penetrate the cell wall more easily. A further mutation (deletion of the uvrB gene) causes an inactivation of the excision repair system.
- Metabolic activation:
- with and without
- Metabolic activation system:
- S9 mix
- Test concentrations with justification for top dose:
- In the pre-experiment the concentration range of the test item was 3 – 5000 µg/plate. The pre-experiment is reported as experiment I. Since toxic effects were observed eight concentrations were tested in experiment II and 5000 µg/plate were chosen as maximal concentration.
The concentration range included two logarithmic decades. The following concentrations were tested in experiment II:
3; 10; 33; 100; 333; 1000; 2500; and 5000 µg/plate
Controls
- Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- yes
- True negative controls:
- no
- Positive controls:
- yes
- Positive control substance:
- other: Without metabolic activation: sodium azide, NaN3; 4-nitro-o-phenylene-diamine, 4-NOPD; methyl methane sulfonate, MMS; With metabolic activation: 2-aminoanthracene, 2-AA
Results and discussion
Test results
- Species / strain:
- S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Vehicle controls validity:
- other: 2500 - 5000 µg/plate
- Untreated negative controls validity:
- valid
- Positive controls validity:
- valid
- Remarks on result:
- other: other:
- Remarks:
- Migrated from field 'Test system'.
Any other information on results incl. tables
In experiment I the plates incubated with the test item showed reduced background growth in all strains at higher concentrations. In experiment II normal background growth was observed in all strains with and without metabolic activation.
Toxic effects evident as a reduction in the number of revertants (below the indication factor of 0.5), occurred in the test groups with and without metabolic activation at higher concentrations.
No substantial increase in revertant colony numbers of any of the five tester strains was observed following treatment with 1,3-Dihydro-4(or5)-methyl-2H-benzimidazole-2-thione at any dose level, neither in the presence nor absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance.
Appropriate reference mutagens were used as positive controls and showed a distinct increase of induced revertant colonies.
Applicant's summary and conclusion
- Conclusions:
- Interpretation of results (migrated information):
negative - Executive summary:
The study was performed to investigate the potential of 1,3-Dihydro-4(or5)-methyl-2Hbenzimidazole-2-thione to induce gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using the Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100, and TA 102.
In experiment I the plates incubated with the test item showed reduced background growth in all strains at higher concentrations. In experiment II normal background growth was observed in all strains with and without metabolic activation.
Toxic effects evident as a reduction in the number of revertants (below the indication factor of 0.5), occurred in the test groups with and without metabolic activation at higher concentrations.
No substantial increase in revertant colony numbers of any of the five tester strains was observed following treatment with 1,3-Dihydro-4(or5)-methyl-2H-benzimidazole-2-thione at any dose level, neither in the presence nor absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance.
Appropriate reference mutagens were used as positive controls and showed a distinct increase of induced revertant colonies.
In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, the test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used.
Therefore, 1,3-Dihydro-4(or5)-methyl-2H-benzimidazole-2-thione was negative in this Salmonella typhimurium reverse mutation assay.
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