Registration Dossier
Registration Dossier
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EC number: 209-502-6 | CAS number: 583-39-1
Endpoint summary
Administrative data
Key value for chemical safety assessment
Effects on developmental toxicity
Description of key information
Available studies suggest any possible effects on developmental toxicity and teratogenicity.
Link to relevant study records
- Endpoint:
- developmental toxicity
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: A reliable secondary source, summaring 2-mercaptobenzimidazole properties, was used. The used secondary source has been updated on 2012; therefore it covers the most updated literature on the substance.
- Qualifier:
- no guideline available
- Principles of method if other than guideline:
- It is not specified.
- GLP compliance:
- not specified
- Species:
- rat
- Strain:
- Wistar
- Route of administration:
- oral: unspecified
- Type of inhalation exposure (if applicable):
- not specified
- Vehicle:
- not specified
- Duration of treatment / exposure:
- Gestation Days 7-17: 0, 3.3, 10, and 30 mg/kg during the period of organogenesis.
Days 7-10, 11-14, or 15-17 of gestation: pregnant rats of three groups were also treated with 60 mg/kg of 2-MBI for 3 or 4 days during specific periods of organogenesis - Details on maternal toxic effects:
- Maternal toxic effects:no data
- Details on embryotoxic / teratogenic effects:
- Embryotoxic / teratogenic effects:yes. Remark: delayed ossification, skeletal variations, rudimentary lumbar ribs, kinked ureter and dilated renal pelvis
- Dose descriptor:
- dose level:
- Effect level:
- >= 10 mg/kg bw/day
- Based on:
- test mat.
- Basis for effect level:
- other: teratogenicity
- Dose descriptor:
- dose level:
- Effect level:
- >= 30 mg/kg bw/day
- Based on:
- test mat.
- Basis for effect level:
- other: teratogenicity
- Dose descriptor:
- dose level:
- Effect level:
- >= 60 mg/kg bw/day
- Based on:
- test mat.
- Basis for effect level:
- other: teratogenicity
- Abnormalities:
- not specified
- Developmental effects observed:
- not specified
- Conclusions:
- According to Directive 67/548/EEC and to Regulation (EC) n. 1272/2008, the substance should be classified for teratogenicity.
Reference
The effects of oral 2-mercaptobenzimidazole (2-MBI) on pregnant Wistar rats were examined. In a preliminary dosefinding study, pregnant rats treated with 2-MBI over Days 7-17 of gestation showed reduction in maternal thymus weights with compound-related mortality at doses > or = 40 mg/kg. No adverse effects on fetuses were found at doses < or = 40 mg/kg. However, anasarca, cleft palate, and dilated lateral ventricles were present in all fetuses from the only
survivor among the dams treated with 60 mg/kg of 2-MBI. In the teratology study, pregnant rats were treated with 2-MBI at doses of 0, 3.3, 10, and 30 mg/kg during the period of organogenesis (Gestation Days 7-17). In addition, pregnant rats of three groups were also treated with 60 mg/kg of 2-MBI for 3 or 4 days during specific periods of organogenesis (Days 7-10, 11-14, or 15-17 of gestation). Treatment on Gestation Days 7-17 resulted in reduced maternal thymus weights at doses of > or = 3.3 mg/kg. In addition to reduced fetal weights, visceral variations (kinked ureter and dilated renal pelvis) and delayed ossification were seen in the fetuses at doses > or = 10 mg/kg, and skeletal variations (rudimentary lumbar ribs) were seen at 30 mg/kg. In the fetuses from the dams treated with 60 mg/kg of 2-MBI,rudimentary lumbar ribs were seen mainly in the group treated on Days 7-10 of gestation, whereas kinked ureter and dilated renal pelvis were evident mainly in the group treated on Gestation Days 15-17
Effect on developmental toxicity: via oral route
- Endpoint conclusion:
- adverse effect observed
- Species:
- rat
Additional information
The substance should be classified as toxic for developmental toxicity.
Justification for selection of Effect on developmental toxicity: via oral route:
This study shows the data with described adverse effects; whereas the other one shows scarced information.
Justification for classification or non-classification
According to Directive 67/548/EEC and to Regulation (EC) n. 1272/2008, the substance should be classified as toxic for developmental toxicity.
Additional information
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.
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