Registration Dossier
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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 218-915-0 | CAS number: 2280-49-1
- 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
Endpoint summary
Administrative data
Key value for chemical safety assessment
Genetic toxicity in vitro
Description of key information
In vitro mutagenicity:
In vitro mutagenic activity was reported in bacterial reverse mutation assays conducted according to OECD TG 471. In mammalian cells, no mutagenic activity was reported in a recent guideline compliant study conducted according to OECD TG 476. The assay was performed in two independent experiments, using two parallel cultures each. The first main experiment was performed with and without liver microsomal activation and a treatment period of 4 hours. The second experiment was performed with a treatment time of 4 hours with and 24 hours without metabolic activation. The highest concentration of 80 μg/mL used in the range finding pre-experiment was limited by cytotoxicity of the test item. The concentration range of the main experiments was also limited by cytotoxicity.
No substantial and reproducible dose dependent increase of the mutation frequency was observed in any part of the main experiments with and without metabolic activation. Appropriate reference mutagens, used as positive controls, induced a distinct increase in mutant colonies and thus, showed the sensitivity of the test system and the activity of the metabolic activation system.
Conclusion on in vitro mutagenicity:
In conclusion it can be stated that the test item did not induce gene mutations at the HPRT locus in V79 cells.
Therefore, N-Phenyl-N-[(trichloromethyl)thio]benzene sulphonamide is considered to be non-mutagenic.
In vitro clastogenicity:
The micronucleus test showed a biologically relevant increase in the frequencies of micronucleus containing V79 cells treated with the test item in the absence or in the presence of S9 mix (4 hours treatment). Thus, an independent repeat experiment with extended treatment time in the absence of S9 mix was not performed in accordance with OECD 487. Evaluation of the data indicates that Vulkalent E is a mutagen in the micronucleus test in vitro, when tested up to cytotoxic concentrations in the absence or presence of metabolic activation.
Link to relevant study records
- Endpoint:
- in vitro cytogenicity / micronucleus study
- Remarks:
- Type of genotoxicity: chromosome aberration
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- 2013
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: Guideline study according to GLP
- Qualifier:
- according to guideline
- Guideline:
- other: OECD Guideline for the testing of chemicals 487. In vitro mammalian cell micronucleus test OECD (2010)
- Deviations:
- no
- Principles of method if other than guideline:
- The purpose of this study was to investigate whether Vulkalent E (N-phenyl-N-[(trichloromethyl)thio]benzenesulphonamide, CAS no.: 2280-49-1) can induce chromosome breakage (structural chromosomal aberrations) or misdistribution of chromosomes leading to aneuploidy, both of which are measured by an increase of the frequency of micronuclei containing mammalian cells in the absence and presence of an extrinsic metabolizing system.
Vulkalent E, dissolved in tetrahydrofuran, was examined for mutagenic activity in the micronucleus test in vitro. The 4 hours treatment was conducted with concentrations of 0.01, 0.05, 0.1, 0.25, 0.5, 0.75, 1, 2.5 and 5 μg/mL without S9 mix and of 0.5, 1, 2.5, 5, 10, 15, 20, 25 and 100 μg/mL with S9 mix.
The in vitro mammalian cell micronucleus test was conducted according to the OECD Guideline for the testing of chemicals 487 (2010). - GLP compliance:
- yes
- Type of assay:
- in vitro mammalian cell micronucleus test
- Target gene:
- When cytogenetic damages leading to chromosomal breakage (clastogenic effects) or
misdistribution of chromosomes (aneugenic effects) are induced during mitosis, chromosomal
fragments or a whole chromosome may be separated from the main nucleus. In interphase the
separated fragment or chromosome can form a tiny nucleus (micronucleus) that exists
independently of the main nucleus in the cytoplasm.
Micronuclei can be seen in a wide variety of cell types. In the micronucleus test employed in
the present study in vitro cultivated V79 cells were used. V79 cells were derived from fetal
lung tissue of Chinese hamsters and are one of the cell lines most widely used for
mutagenicity studies (3). In common with all cell lines they do not possess the full ability of
mammals to activate promutagenic and procarcinogenic compounds. To overcome this
deficiency the compounds are tested in the presence of an exogenous metabolizing system.
Postmitochondrial supernatant fraction from liver of Aroclor 1254-treated male rats and a
NADPH-generating system have been successfully used in prokaryotic and eukaryotic in vitro
systems for the activation of various compounds. - Species / strain / cell type:
- Chinese hamster lung fibroblasts (V79)
- Additional strain / cell type characteristics:
- not specified
- Metabolic activation:
- with and without
- Metabolic activation system:
- Postmitochondrial supernatant fraction from liver of Aroclor 1254-treated male rats (S9).
- Test concentrations with justification for top dose:
- Vulkalent E, dissolved in tetrahydrofuran, was examined for mutagenic activity in the
micronucleus test in vitro. The 4 hours treatment was conducted with concentrations of 0.01,
0.05, 0.1, 0.25, 0.5, 0.75, 1, 2.5 and 5 μg/mL without S9 mix and of 0.5, 1, 2.5, 5, 10, 15, 20,
25 and 100 μg/mL with S9 mix. - Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- yes
- True negative controls:
- yes
- Positive controls:
- yes
- Positive control substance:
- cyclophosphamide
- mitomycin C
- Species / strain:
- Chinese hamster lung fibroblasts (V79)
- Metabolic activation:
- with and without
- Genotoxicity:
- positive
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- valid
- Positive controls validity:
- valid
- Executive summary:
The micronucleus test showed a biologically relevant increase in the frequencies of
micronucleus containing V79 cells treated with the test item in the absence or in the presence
of S9 mix (4 hours treatment). Thus, an independent repeat experiment with extended
treatment time in the absence of S9 mix was not performed in accordance with OECD 487.
Evaluation of the data indicates that Vulkalent E is a mutagen in the micronucleus test in
vitro, when tested up to cytotoxic concentrations in the absence or presence of metabolic
activation.
- Endpoint:
- in vitro gene mutation study in mammalian cells
- Remarks:
- Type of genotoxicity: gene mutation
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- 2013
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: Guideline study according to GLP
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
- Deviations:
- no
- GLP compliance:
- yes
- Type of assay:
- mammalian cell gene mutation assay
- Target gene:
- HPRT (hypoxanthine-guanine phosphoribosyl transferase) catalyzes the conversion of the nontoxic 6-TG (6-thioguanine) to its toxic ribophosphorylated derivative. Therefore, cells deficient in HPRT due to a forward mutation are resistant to 6-TG. These cells are able to proliferate in the presence of 6-TG whereas the non-mutated cells die.
- Species / strain / cell type:
- Chinese hamster lung fibroblasts (V79)
- Additional strain / cell type characteristics:
- not applicable
- Metabolic activation:
- with and without
- Metabolic activation system:
- mammalian liver microsome preparations (S9 mix)
- Test concentrations with justification for top dose:
- The highest concentration of 80 μg/mL used in the range finding pre-experiment was limited by cytotoxicity of the test item. The concentration range of the main experiments was also limited by cytotoxicity.
0, 1.3, 2.5, 5, 10, 20, 40, 80 µg/ml - Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- yes
- True negative controls:
- yes
- Positive controls:
- yes
- Positive control substance:
- 7,12-dimethylbenzanthracene
- methylmethanesulfonate
- Key result
- Species / strain:
- Chinese hamster lung fibroblasts (V79)
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Remarks:
- First experiment: 0.15 μg/mL and above without metabolic activation and at 24.0 μg/mL with metabolic activation. Second experiment: above were noted at 0.45 μg/mL and above without metabolic activation and at 24.0 μg/mL and above with metabolic activation
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not specified
- Positive controls validity:
- valid
- Remarks on result:
- other: N-Phenyl-N-[(trichloromethyl)thio]benzene sulphonamide is considered to be non-mutagenic in this HPRT assay.
- Executive summary:
In conclusion it can be stated that under the experimental conditions reported the test item did not induce gene mutations at the HPRT locus in V79 cells.
Therefore, N-Phenyl-N-[(trichloromethyl)thio]benzene sulphonamide is considered to be non-mutagenic in this HPRT assay.
- Endpoint:
- in vitro gene mutation study in bacteria
- Remarks:
- Type of genotoxicity: gene mutation
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- 1981
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Scientifically reliable; non GLP
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 471 (Bacterial Reverse Mutation Assay)
- Deviations:
- yes
- Remarks:
- 4 bacterial straines tested
- GLP compliance:
- no
- Type of assay:
- bacterial reverse mutation assay
- Target gene:
- histidine synthesis
- Species / strain / cell type:
- S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
- Metabolic activation:
- with and without
- Metabolic activation system:
- S9 derived from male rat liver
- Test concentrations with justification for top dose:
- 12500, 2500, 500, 100, 20 µg/plate
- Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- yes
- True negative controls:
- yes
- Positive controls:
- yes
- Remarks:
- Endoxan, Trypaflavin, 2-Amino-anthrazen
- Positive control substance:
- other: Endoxan, Trypaflavin, 2-Amino-anthrazen
- Species / strain:
- S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
- Metabolic activation:
- with and without
- Genotoxicity:
- positive
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- valid
- Positive controls validity:
- valid
- Executive summary:
Biologically and statistically increase in mutation rate was observed.
- Endpoint:
- in vitro gene mutation study in bacteria
- Remarks:
- Type of genotoxicity: gene mutation
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- 1980
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Scientifically reliable; non GLP
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 471 (Bacterial Reverse Mutation Assay)
- Deviations:
- yes
- Remarks:
- 4 bacterial straines tested
- GLP compliance:
- no
- Type of assay:
- bacterial reverse mutation assay
- Target gene:
- histidine synthesis
- Species / strain / cell type:
- S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
- Metabolic activation:
- with and without
- Metabolic activation system:
- S9 derived from male rat liver
- Test concentrations with justification for top dose:
- 12500, 2500, 500, 100, 20 µg/plate
- Untreated negative controls:
- yes
- Negative solvent / vehicle controls:
- yes
- True negative controls:
- yes
- Positive controls:
- yes
- Remarks:
- Endoxan, Trypaflavin, 2-Amino-anthrazen
- Positive control substance:
- other: Endoxan, Trypaflavin, 2-Amino-anthrazen
- Species / strain:
- S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
- Metabolic activation:
- with and without
- Genotoxicity:
- positive
- Cytotoxicity / choice of top concentrations:
- cytotoxicity
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- valid
- Positive controls validity:
- valid
- Executive summary:
Biologically and statistically increase in mutation rate was observed.
Referenceopen allclose all
Vulkalent E, dissolved in tetrahydrofuran, was examined for mutagenic activity in the
micronucleus test in vitro. The 4 hours treatment was conducted with concentrations of 0.01,
0.05, 0.1, 0.25, 0.5, 0.75, 1, 2.5 and 5 μg/mL without S9 mix and of 0.5, 1, 2.5, 5, 10, 15, 20,
25 and 100 μg/mL with S9 mix.
Without S9 mix cytotoxic effects were observed at 0.25 μg/mL and above after 4 hours
treatment. With S9 mix cytotoxic effects were observed at 15 μg/mL and above. Precipitation
in the medium could be observed starting at 100 μg/mL.
Therefore, concentrations of 0.1, 0.25 and 0.5 μg/mL (without S9 mix, 4 hours treatment) 2.5,
10 and 15 μg/mL (with S9 mix, 4 hours treatment) were chosen for reading. Higher
concentrations were excluded from evaluation for micronuclei due to excessive cytotoxicity.
Solvent control (tetrahydrofuran) and appropriate positive controls with known mutagens
(mitomycin C, cyclophosphamide) demonstrated the suitability and sensitivity of the test
system.
The micronucleus test showed a biologically relevant increase in the frequencies of
micronucleus containing V79 cells treated with the test item in the absence or in the presence
of S9 mix (4 hours treatment). Thus, an independent repeat experiment with extended
treatment time in the absence of S9 mix was not performed in accordance with OECD 487.
Evaluation of the data indicates that Vulkalent E is a mutagen in the micronucleus test in
vitro, when tested up to cytotoxic concentrations in the absence or presence of metabolic
activation.
The assay was performed in two independent experiments, using two parallel cultures each. The first main experiment was performed with and without liver microsomal activation and a treatment period of 4 hours. The second experiment was performed with a treatment time of 4 hours with and 24 hours without metabolic activation.
The highest concentration of 80 μg/mL used in the range finding pre-experiment was limited by cytotoxicity of the test item. The concentration range of the main experiments was also limited by cytotoxicity.
No substantial and reproducible dose dependent increase of the mutation frequency was observed in any part of the main experiments with and without metabolic activation.
Appropriate reference mutagens, used as positive controls, induced a distinct increase in mutant colonies and thus, showed the sensitivity of the test system and the activity of the metabolic activation system.
Conclusion:
In conclusion it can be stated that under the experimental conditions reported the test item did not induce gene mutations at the HPRT locus in V79 cells.
Therefore, N-Phenyl-N-[(trichloromethyl)thio]benzene sulphonamide is considered to be non-mutagenic in this HPRT assay.
Cytotoxicity was observed at concentrations above 500 µg/plate
precipitation was observed at or above 2500µg/plate
Biological significant increase in mutationrats were observed at or above 20 µg/plate for TA 1535, TA 100 and TA 98 and at or above 100 µg/plate for TA 1537
Cytotoxicity was observed at concentrations above 500 µg/plate
precipitation was observed at or above 2500µg/plate
Biological significant increase in mutationrats were observed at or above 20 µg/plate for all strains tested
Endpoint conclusion
- Endpoint conclusion:
- adverse effect observed (positive)
Genetic toxicity in vivo
Description of key information
The test item N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide was assessed in the micronucleus assay for its potential to induce micronuclei in polychromatic erythrocytes (PCE) in the bone marrow of the rat according to OECD TG 474.
Under the experimental conditions reported, N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide did not induce micronuclei as determined by the micronucleus test with bone marrow cells of the rat. Therefore, N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide is considered to be nonmutagenic in this in vivo micronucleus assay.
Link to relevant study records
- Endpoint:
- in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: GLP guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
- Principles of method if other than guideline:
- The study was performed to investigate the potential of N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide to induce micronuclei in polychromatic erythrocytes (PCE) in the bone marrow of the rat according to OECD TG 474.
- GLP compliance:
- yes
- Type of assay:
- micronucleus assay
- Species:
- rat
- Strain:
- Wistar
- Sex:
- male
- Route of administration:
- oral: gavage
- Duration of treatment / exposure:
- 24 or 48 hours
- Frequency of treatment:
- orally once by gastric gavage
- Remarks:
- Doses / Concentrations:
24 h preparation interval: 125, 250, and 500 mg/kg b.w.. 48 h preparation interval: 500 mg/kg b.w..
Basis:
nominal conc. - No. of animals per sex per dose:
- Number of animals for the main study: 42 males
- Control animals:
- yes, concurrent vehicle
- Tissues and cell types examined:
- 24 h and 48 h after a single administration of the test item in the bone marrow cells were collected for micronuclei analysis.
Seven males per test group were evaluated for the occurrence of micronuclei. Per animal 4000 polychromatic erythrocytes were scored for micronuclei.
To investigate a cytotoxic effect due to the treatment with the test item the ratio between polychromatic and normochromatic erythrocytes was determined in the same sample and reported as the number of PCEs per total erythrocytes. - Key result
- Sex:
- male
- Genotoxicity:
- negative
- Toxicity:
- yes
- Remarks:
- Systemic toxicity; ruffled fur, reduced spontaneous activity and eyelid closure in animals treated with the high dose of test item
- Vehicle controls validity:
- valid
- Remarks:
- The vehicle of the test item was used as negative control.
- Negative controls validity:
- valid
- Positive controls validity:
- valid
- Conclusions:
- Interpretation of results (migrated information): negative
In conclusion, it can be stated that under the experimental conditions reported, the test item N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide did not induce micronuclei as determined by the micronucleus test with bone marrow cells of the rat.
Therefore, N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide is considered to be nonmutagenic in this in vivo micronucleus assay. - Executive summary:
This study was performed to investigate the potential of N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide to induce micronuclei in polychromatic erythrocytes (PCE) in the bone marrow of the rat according to OECD TG 474.
The test item was suspended in corn oil, which was also used as vehicle control. The dose volume administered orally was 10 mL/kg b.w..
24 h and 48 h after a single administration of the test item in the bone marrow cells were collected for micronuclei analysis.
Seven males per test group were evaluated for the occurrence of micronuclei. Per animal 4000 polychromatic erythrocytes were scored for micronuclei.
To investigate a cytotoxic effect due to the treatment with the test item the ratio between polychromatic and normochromatic erythrocytes was determined in the same sample and reported as the number of PCEs per total erythrocytes.
The following dose levels of the test item were investigated:
24 h preparation interval: 125, 250, and 500 mg/kg b.w..
48 h preparation interval: 500 mg/kg b.w..
The highest dose (500 mg/kg b.w.) was estimated by a pre-experiment. This maximal tolerated dose (MTD) is based on substantial clinical symptoms in the main experiment which included ruffled fur, reduced spontaneous activity and eyelid closure in animals treated with the high dose of test item. Animals treated with the mid dose level exhibited ruffled fur only. Furthermore, body weight loss was observed in many of the animals treated with the high dose of the test item, and also in some animals treated with the mid dose of the test item. The animals treated with the low dose and the vehicle control did not exhibit any clinical symptoms or loss in body weight.
The observed systemic toxicity at the tested doses is indicative for a systemic distribution of the test item. Thus, bioavailability of the test item under the tested conditions is assumed.
After treatment with the test item the number of polychromatic erythrocytes (PCE) was not substantially decreased as compared to the mean value of PCEs of the vehicle control thus indicating that N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide did not exert any cytotoxic effects in the bone marrow.
In comparison to the corresponding vehicle controls there was no biologically relevant or statistically significant enhancement in the frequency of the detected micronulclei at any preparation interval after administration of the test item and with any dose level used. 20
mg/kg b.w. cyclosphosphamide administered orally was used as positive control which induced a substantial and statistically significant increase in cells with micronuclei (p<0.01).
In conclusion, it can be stated that under the experimental conditions reported, the test item N-Phenyl-N-[(trichloromethyl)thio] benzenesulphonamide did not induce micronuclei as determined by the micronucleus test with bone marrow cells of the rat.
Therefore, N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide is considered to be nonmutagenic in this in vivo micronucleus assay.
Reference
Results
Calculation and Results of Individual Data
Pre-Experiment for Toxicity
The animals treated in the pre-experiments received the test item N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide suspended in corn oil once orally. The volume administered was 10 mL/kg b.w.. The following dose level was tested and expressed
clinical symptoms are shown in the table:
hours post-treatment | ||||||
Clinical Symptoms | 0 - 1 | 2-4 | 5-6 | 24 | 30 | 48 |
1st Pre-experiment: 500 mg/kg b.w.; 2 males / 2 females | ||||||
Reduction of spontaneous activity | 0/0 | 1/2 | 1/2 | 2/1 | 1/0 | 0/0 |
Isolation (Retreat) | 0/0 | 1/0 | 1/0 | 0/0 | 0/0 | 0/0 |
Ruffled fur | 0/0 | 2/2 | 2/2 | 2/1 | 2/1 | 2/1 |
Hunchback | 0/0 | 1/1 | 1/0 | 0/0 | 0/0 | 0/0 |
Eyelid closure (partially) | 0/0 | 1/1 | 1/1 | 1/0 | 0/0 | 0/0 |
On the basis of these data 500 mg/kg b.w. were estimated to be suitable.
No substantial differences between sexes in toxicity were observed, so that only male animals were used in the main experiment.
Clinical examinations in the Main Experiment
In the main experiment for each test item dose group 7 males received the test item NPhenyl-N-[(trichloromethyl)thiobenzene-sulphonamide suspended in corn oil once orally.
The volume administered was 10 mL/kg b.w.. The clinical symptoms observed following treatment are shown in the following table for each dose group, which indicates the number of animals with findings.
hours post-treatment (males) | |||||
Clinical symptoms | 1 | 2-4 | approx 5 | 24 | 48 |
High dose: 500 mg/kg b.w. (14 males at 1 to 24 h; 7 males at 48 h) | |||||
reduction of spontaneous activity | 0 | 7 | 8 | 1 | 0 |
eyelid closure (partially) | 0 | 4 | 4 | 0 | 0 |
ruffled fur | 0 | 11 | 14 | 14 | 2 |
Medium dose: 250 mg/kg b.w. (7 males) | |||||
ruffled fur | 0 | 3 | 4 | 0 | 0 |
The animals treated with the vehicle control (corn oil) and the low dose of the test item did
not express any clinical symptoms.
Summary of Micronucleus Test Results
TestGroup | Dosemg/kgb.w. | samplingtime | meanMN/4000PCE | SDMN/4000PCE | mean %MN/4000 | Range MN | RatioPCE/totalEry | PCE% ratioVehicle | |
min | max | ||||||||
Corn Oil | 0 | 24 | 12.0 | 7.4 | 0.3 | 1 | 22 | 0.547 | 100.00 |
Dose 1 | 125 | 24 | 8.3 | 4.9 | 0.2 | 4 | 18 | 0.510 | 93.24 |
Dose 2 | 250 | 24 | 10.6 | 5.3 | 0.3 | 5 | 18 | 0.474 | 86.65 |
Dose 3 | 500 | 24 | 10.3 | 4.0 | 0.3 | 4 | 17 | 0.511 | 93.42 |
Positive | 20 | 24 | 68.6 | 30.7 | 1.7 | 47 | 118 | 0.432 | 78.98 |
Dose 3 | 500 | 48 | 4.7 | 1.8 | 0.1 | 3 | 8 | 0.481 | 87.93 |
MN = micronuclei
Biometry
Statistical significance at the five per cent level (p < 0.05) was evaluated by means of the non-parametric Mann-Whitney test using the validated statistical program RScript Wilcoxon_2.Rnw.
Negative control versus test group | Significance | p |
Dose 1 - 125 mg N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide/kg b.w.;24 h | - | 0.672 |
Dose 2 - 250 mg N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide/kg b.w.;24 h | - | 1.000 |
Dose 3 - 500 mg N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide/kg b.w.;24 h | - | 1.000 |
Positive Control - 40 mg CPA/kg b.w.; 24 h | + | 0.010 |
Dose 3 - 500 mg N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide/kg b.w.;48 h | - | 0.136 |
- = not significant
+ = significant
Discussuion
The test item N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide was assessed in the micronucleus assay for its potential to induce micronuclei in polychromatic erythrocytes (PCE) in the bone marrow of the rat according to OECD TG 474.
The test item was suspended in corn oil, which was also used as vehicle control. The volume administered orally was 10 mL/kg b.w..
24 h and 48 h after a single administration of the test item the bone marrow cells were collected for micronuclei analysis.
Seven males per test group were evaluated for the occurrence of micronuclei. Per animal 4000 polychromatic erythrocytes (PCEs) were scored for micronuclei.
To investigate a cytotoxic effect due to the treatment with the test item the ratio between polychromatic and normochromatic erythrocytes was determined in the same sample and reported as the number of PCEs per total erythrocytes.
The following dose levels of the test item were investigated:
24 h preparation interval: 125, 250, and 500 mg/kg b.w..
48 h preparation interval: 500 mg/kg b.w..
As estimated by a pre-experiment 500 mg N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide per kg b.w. was suitable as highest treatment dose.The maximal tolerated dose (MTD) is based on substantial clinical symptoms in the main experiment which included ruffled fur, reduced spontaneous activity and eyelid closure in the animals treated with the high dose of test item. Animals treated with the mid dose level exhibited ruffled fur only. Furthermore, body weight loss was observed in many of the animals treated with the high dose of the test item, and also in some animals treated with the mid dose of the test item. The animals treated with the low dose and the vehicle control did not exhibit
any clinical symptoms or loss in body weight.
The mean number of polychromatic erythrocytes (PCE) was not substantially decreased after treatment with the test item as compared to the mean value of PCEs of the vehicle control indicating that N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide did not have any cytotoxic properties in the bone marrow.
In comparison to the corresponding vehicle controls there was no statistically significant or biologically relevant enhancement in the frequency of the detected micronuclei at any preparation interval and dose level after administration of the test item.
The mean values of micronuclei observed after treatment with N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide were below to the value of the vehicle control group.
20 mg/kg b.w. cyclophosphamide administered orally was used as positive control which showed a substantial and statistically significant increase of induced micronucleus
frequency (p>0.01).
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (negative)
Mode of Action Analysis / Human Relevance Framework
N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide is positive in the bacterial reverse mutation assay and an in-vitro MNT.
The compound was negative in a cell mutation assay in V79 cells (OECD TG 476).
N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide was assessed in the micronucleus assay for its potential to induce micronuclei in polychromatic erythrocytes (PCE) in the bone marrow of the rat according to OECD TG 474.
Under the experimental conditions reported, N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide did not induce micronuclei as determined by the micronucleus test with bone marrow cells of the rat. Therefore, N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide is considered to be nonmutagenic in this in vivo micronucleus assay.
Overall, the compound is not considered to be mutagenic.
Additional information
In vitro mutagenicity:
In vitro mutagenic activity was reported in bacterial reverse mutation assays conducted according to OECD TG 471. In mammalian cells, no mutagenic activity was reported in a recent guideline compliant study conducted according to OECD TG 476. The assay was performed in two independent experiments, using two parallel cultures each. The first main experiment was performed with and without liver microsomal activation and a treatment period of 4 hours. The second experiment was performed with a treatment time of 4 hours with and 24 hours without metabolic activation. The highest concentration of 80 μg/mL used in the range finding pre-experiment was limited by cytotoxicity of the test item. The concentration range of the main experiments was also limited by cytotoxicity.
No substantial and reproducible dose dependent increase of the mutation frequency was observed in any part of the main experiments with and without metabolic activation. Appropriate reference mutagens, used as positive controls, induced a distinct increase in mutant colonies and thus, showed the sensitivity of the test system and the activity of the metabolic activation system.
Conclusion on in vitro mutagenicity:
In conclusion it can be stated that the test item did not induce gene mutations at the HPRT locus in V79 cells.
Therefore, N-Phenyl-N-[(trichloromethyl)thio]benzene sulphonamide is considered to be non-mutagenic.
In vitro clastogenicity:
The micronucleus test showed a biologically relevant increase in the frequencies of micronucleus containing V79 cells treated with the test item in the absence or in the presence of S9 mix (4 hours treatment). Thus, an independent repeat experiment with extended treatment time in the absence of S9 mix was not performed in accordance with OECD 487. Evaluation of the data indicates that Vulkalent E is a mutagen in the micronucleus test in vitro, when tested up to cytotoxic concentrations in the absence or presence of metabolic activation.
In-vivo mutagenicity:
The test item N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide was assessed in the micronucleus assay for its potential to induce micronuclei in polychromatic erythrocytes (PCE) in the bone marrow of the rat according to OECD TG 474.
Under the experimental conditions reported, N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide did not induce micronuclei as determined by the micronucleus test with bone marrow cells of the rat. Therefore, N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide is considered to be nonmutagenic in this in vivo micronucleus assay.
Overall, the compound is considered to be not mutagenic
Justification for classification or non-classification
N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide is positive in the bacterial reverse mutation assay and an in-vitro MNT.
The compound was negative in a cell mutation assay in V79 cells (OECD TG 476).
N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide was assessed in the micronucleus assay for its potential to induce micronuclei in polychromatic erythrocytes (PCE) in the bone marrow of the rat according to OECD TG 474.
Under the experimental conditions reported, N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide did not induce micronuclei as determined by the micronucleus test with bone marrow cells of the rat. Therefore, N-Phenyl-N-[(trichloromethyl)thio]benzenesulphonamide is considered to be nonmutagenic in this in vivo micronucleus assay.
Overall, the compound is considered to be not mutagenic.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.