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EC number: 253-326-2 | CAS number: 37052-78-1
- 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
Skin sensitisation
Administrative data
- Endpoint:
- skin sensitisation: in vivo (non-LLNA)
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1 September - 26 September 1987.
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 1 987
- Report date:
- 1987
Materials and methods
Test guideline
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 406 (Skin Sensitisation)
- GLP compliance:
- yes
- Type of study:
- guinea pig maximisation test
- Justification for non-LLNA method:
- The study was performed in 1990 before the LLNA method had been validated.
Test material
- Reference substance name:
- 1,3-dihydro-5-methoxy-2H-benzimidazole-2-thione
- EC Number:
- 253-326-2
- EC Name:
- 1,3-dihydro-5-methoxy-2H-benzimidazole-2-thione
- Cas Number:
- 37052-78-1
- Molecular formula:
- C8H8N2OS
- IUPAC Name:
- 5-methoxy-1,3-dihydro-2H-benzimidazole-2-thione
Constituent 1
- Specific details on test material used for the study:
- Batch no. : 685 20-01.
Purity: 99.2%.
In vivo test system
Test animals
- Species:
- guinea pig
- Strain:
- Dunkin-Hartley
- Sex:
- female
- Details on test animals and environmental conditions:
- The guinea-pigs selected for the study were all acclimated to the laboratory environment.
Mean weight: 426 grams
The guinea-pigs were housed in suspended cages with wire mesh floors . They had free access to tap water and a Vitamin C-enriched Guinea-Pig Diet. Hay was given once weekly.
Animal room temperature was approximately 21°C and relative humidity 30-70%.
Air exchange was maintained at approximately 15 air changes per hour and lighting was controlled by means of a time switch to give 12 hours of artificial light in each 24 hour period.
Study design: in vivo (non-LLNA)
Inductionopen allclose all
- Route:
- intradermal
- Vehicle:
- other: liquid paraffin
- Concentration / amount:
- Injection 1: 0,1 ml FCA in water,
Injection 2: 0,1 ml Metmercazole 5 w/w% in liquid paraffin
Injection 3: 0,1 ml, Metmercazole 5% wjw in a 50 : 50 mixture of Freund's
complete adjuvant and liquid paraffin.
- Route:
- epicutaneous, occlusive
- Vehicle:
- other: Liquid paraffin
- Concentration / amount:
- 50 w/w%
- Day(s)/duration:
- A week after the injections; application 48 hours
Challenge
- Route:
- epicutaneous, open
- Vehicle:
- other: liquid paraffin
- Concentration / amount:
- 25 och 50 w/w%
- Day(s)/duration:
- 24 hours
- No. of animals per dose:
- 20
20 control animals - Details on study design:
- Induction: 20 animals were given 3 injections:1. Freund's complete adjuvant was diluted with anequal volume of water for irrigation, 2. Metmercazole, 5% wjw in liquid paraffin, 3 . Metmercazole, 5% wjw in a 50 : 50 mixture of Freund's complete adjuvant and liquid paraffin.
Topical appl ication (induction phase): One week after the injections :2 x 4 cm patch of Whatman No. 3 paper was saturated with Metmercazole, 50% w/w in liquid paraffin. The patch was
placed on the skin and covered by a length of impermeable plastic adhesive tape. The dressing was left in place for 48 hours.
Control animals: During the induction period the control animals were treated similarly to the test animals with the exception that the test compound was omitted from the intradermal injections and topical application.
Challange: The test and control animals were challenged topically two weeks after the induction period using Metmercazole, 50% and 25% w;w in liquid paraffin.
The challenge sites were evaluated 24, 48 and 72 hours after removal of the patches.
Results and discussion
In vivo (non-LLNA)
Resultsopen allclose all
- Reading:
- 1st reading
- Hours after challenge:
- 24
- Group:
- test chemical
- Dose level:
- 25 w/w% and 50 w/w%
- No. with + reactions:
- 19
- Total no. in group:
- 20
- Remarks on result:
- positive indication of skin sensitisation
- Reading:
- 2nd reading
- Hours after challenge:
- 48
- Group:
- test chemical
- Dose level:
- 25 w/w% and 50 w/w%
- No. with + reactions:
- 19
- Total no. in group:
- 20
- Remarks on result:
- positive indication of skin sensitisation
- Reading:
- other: 3rd reading
- Hours after challenge:
- 72
- Group:
- test chemical
- Dose level:
- 25 w/w% and 50 w/w%
- No. with + reactions:
- 19
- Total no. in group:
- 20
- Remarks on result:
- positive indication of skin sensitisation
- Reading:
- 1st reading
- Hours after challenge:
- 24
- Group:
- negative control
- Dose level:
- 25 w/w% and 50 w/w%
- No. with + reactions:
- 0
- Total no. in group:
- 20
- Reading:
- 2nd reading
- Hours after challenge:
- 48
- Group:
- negative control
- Dose level:
- 25 w/w% and 50 w/w%
- No. with + reactions:
- 0
- Total no. in group:
- 20
- Reading:
- other: 3rd reading
- Hours after challenge:
- 72
- Group:
- negative control
- Dose level:
- 25 w/w% and 50 w/w%
- No. with + reactions:
- 0
- Total no. in group:
- 20
Applicant's summary and conclusion
- Interpretation of results:
- Category 1 (skin sensitising) based on GHS criteria
- Conclusions:
- In this screening test, performed in twenty albino guinea-pigs, Metmercazole produced evidence of delayed contact hypersensitivity in nineteen animals. The material is a skin sensitiser according to this test.
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