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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
Repeated dose toxicity: oral
Administrative data
- Endpoint:
- short-term repeated dose toxicity: oral
- Type of information:
- migrated information: read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: sufficient documented and scientifically acceptable
Cross-reference
- Reason / purpose for cross-reference:
- reference to same study
Data source
Reference
- Reference Type:
- publication
- Title:
- Toxicity study of a rubber antioxidant, mixture of 2-mercaptomethylbenzimidazoles, by repeated oral administration to rats
- Author:
- Saitoh M, Umemura T, Kawasaki Y, Momma Y, Matsushima Y, Sakemi K, Isama K, Kitajima S, Ogawa Y, Hasegawa R, Suzuki T, Hayashi M, Inoue T, Ohno Y, Sofuni T, Kurokawa Y, Tsuda M
- Year:
- 1 999
- Bibliographic source:
- Food Chem Toxicol 37, 777-787
Materials and methods
- Principles of method if other than guideline:
- Male and female rats were treated with MMBIs (2-mercaptomethylbenzimidazoles (a 1:1 mixture of 4-methyl and 5-methyl isomers, MMBIs) by gavage at doses 0 (corn oil), 4, 20 and 100 mg/kg for 28 consecutive days followed by a 2-week recovery period for the control and highest dose groups. Body weight and food consumption, clinical signs, organ weights, clinical biochemistry and hematological parameters including clotting times and micronuclei induction in bone marrow erythropoeitic cells were recorded and a histopathological examination was conducted.
- GLP compliance:
- not specified
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:
- 2-Methylmercaptobenzimidazoles (MMBIs, CAS no 53988-10-6, a 1:1 mixture of 2-mercapto-4-methylbenzimidazole, CAS no 27231-33-0 and 2-mercapto-5-methylbenzimidazole, 27231-36-3, mol.wt 164.23 were obtained from Ouchi Shinko Chemical Ind. Ltd (Osaka, Japan)
Constituent 1
Test animals
- Species:
- rat
- Strain:
- Wistar
- Sex:
- male/female
Administration / exposure
- Route of administration:
- oral: gavage
- Vehicle:
- corn oil
- Analytical verification of doses or concentrations:
- not specified
- Duration of treatment / exposure:
- 28 days
- Frequency of treatment:
- daily
Doses / concentrations
- Remarks:
- Doses / Concentrations:
0, 2, 10, 25, 50, 100, or 150 mg/kg
Basis:
other: nominal
- No. of animals per sex per dose:
- 5 male and 5 female rats/group
- Control animals:
- yes, concurrent vehicle
Results and discussion
Effect levels
open allclose all
- Dose descriptor:
- NOAEL
- Effect level:
- 4 mg/kg bw/day (nominal)
- Based on:
- test mat.
- Sex:
- male
- Basis for effect level:
- other: thyroid toxicity
- Dose descriptor:
- NOAEL
- Effect level:
- 20 mg/kg bw/day (nominal)
- Based on:
- test mat.
- Sex:
- female
- Basis for effect level:
- other: thyroid toxicity
Target system / organ toxicity
- Critical effects observed:
- not specified
Any other information on results incl. tables
Relative organ weights of lung, liver, kidney, and serum cholesterol and phospholipid significantly increased in male rats treated with MMBIs at doses of 20 and 100 mg/kg bw/d. Male rats administered 100 mg/kg bw/d exhibited a 1.8 fold increase in thyroid weight associated with histopathological changes but not altered serum thyroid hormone levels. Haematology and urine analysis were uneffected. Female rats administered 100 mg/kg bw/d MMBIs exhibited significant increases of liver and kidney but not thyroid weights and serum cholesterol levels.
Reproductive organs of the rats were examined histopathologically. No adverse effects were reported from these organs. Based on these results there are no indications for specific adverse effects on the reproductive organs up to 100 mg/kg bw/day
Applicant's summary and conclusion
- Executive summary:
Male and female rats were treated orally by gavage with 2-mercaptomethylbenzimidazole at doses of 0 (corn oil), 4, 20 and 100 mg/kg bw for 28 consecutive days. Clinical signs, body weight, food consumption, organ weights, clinical biochemistry and hematological parameters were recorded and autopsy was conducted.
Relative organ weights of lung, liver, kidney, and serum cholesterol and phospholipid significantly increased in male rats treated with MMBIs at doses of 20 and 100 mg/kg bw/d. Male rats administered 100 mg/kg bw/d exhibited a 1.8 fold increase in thyroid weight associated with histopathological changes but not altered serum thyroid hormone levels. Haematology and urine analysis were uneffected. Female rats administered 100 mg/kg bw/d MMBIs exhibited significant increases of liver and kidney but not thyroid weights and serum cholesterol levels.
Reproductive organs of the rats were examined histopathologically. No adverse effects were reported from these organs. Based on these results there are no indications for specific adverse effects on the reproductive organs up to 100 mg/kg bw/day.
The no-observed-effect levels for male and female rats were found to be 4 and 20 mg/kg bw/d, respectively
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