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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 200-822-1 | CAS number: 74-93-1
- 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
Neurotoxicity
Administrative data
- Endpoint:
- neurotoxicity: acute inhalation
- Type of information:
- experimental study
- Adequacy of study:
- other information
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Study well documented, meets generally accepted scientific principles, acceptable for assessment
Data source
Reference
- Reference Type:
- publication
- Title:
- Synergism between mercaptans and ammonia or fatty acids in the production of coma-A possible role for mercaptans in the pathogenesis of hepatic coma
- Author:
- Zieve L, Doizaki WM, Zieve FJ
- Year:
- 1 974
- Bibliographic source:
- J. Lab. Clin. Med., 83, 16-28
Materials and methods
Test guideline
- Qualifier:
- no guideline followed
- Principles of method if other than guideline:
- The coma-producing properties of methanethiol were studies in rats.
- GLP compliance:
- not specified
- Limit test:
- no
Test material
- Reference substance name:
- Methanethiol
- EC Number:
- 200-822-1
- EC Name:
- Methanethiol
- Cas Number:
- 74-93-1
- Molecular formula:
- CH4S
- IUPAC Name:
- methanethiol
- Details on test material:
- Source: Eastman Organic Chemicals, Rochester, N. Y.
Purity was confirmed by injecting the material received into the gas chromatograph and observing a single peak.
Constituent 1
Administration / exposure
- Route of administration:
- inhalation: vapour
- Vehicle:
- unchanged (no vehicle)
- Details on exposure:
- Methyl mercaptan was administered in the gas phase. Rats were placed singly in a 27 liter desiccator, with the opening in the lid covered by a rubber septum through which the compound could be injected into the chamber. In each instance the test animal was placed inside the appropriate chamber prior to the injection of the dose of the compound.
- Analytical verification of doses or concentrations:
- no
- Details on analytical verification of doses or concentrations:
- The mercaptan content of the gas phase in the chamber was not routinely analyzed; the concentrations recorded in individual experiments were calculated from the dose injected. At gas-chamber concentrations of 1 per cent by volume, the differences between calculated and measured values were less than 5 per cent; at 0.5 per cent by volume, less than 10 per cent; at 0.2 per cent by volume, less than 15 per cent; and at 0.1 per cent by volume, less than 25 per cent. The error of measurement of these mercaptans by gas chromatography was less than 5 per cent.
- No. of animals per sex per dose:
- 3-8
Examinations
- Observations and clinical examinations performed and frequency:
- For the construction of the dose-response curves, the animais were observed until they became comatose or until 15 minutes after the administration of the compound. Coma was defined as complete loss of the righting reflex. Each point on the curves was based upon at least 3 and as many as 8 rats. All animals recovered consciousness within 30 minutes.
- Statistics:
- For each curve a CD50. was defined as the dose causing coma in 50 per cent of the animals. It was obtained by dropping a vertical line to the x-axis from the point on the dose-response curve corresponding to a 50 per cent coma incidence.
Results and discussion
Results of examinations
- Clinical signs:
- effects observed, treatment-related
- Mortality:
- mortality observed, treatment-related
- Details on results:
- The CD50 for methanethiol was approximately 0.16% by volume (1% = 0.44 mmoles/l). Coma occurred in 100 per cent of rats when the dose of methanethiol given was 0.2 per cent, and the largest dose of methanethiol which produced no coma was 0.12 per cent.
The rats went through a brief excitement phase before they became groggy. With doses producing coma in 50 per cent of animals, the excitement phase lasted approximately 2 minutes, then passed quickly into a phase lasting 1 minute in which the rat became groggy and lethargic. This was followed in the next minute or two by frank coma, the rat falling to its side and rolling over on its back as the chamber was tipped up slightly. With smaller doses the excitement phase and the pre-coma phase were prolonged; with larger doses the entire sequence occurred more quickly. If the rat was removed from the chamber as soon as he became comatose, the coma did not last more than 30 minutes as a rule, and upon recovery the rat appeared and remained alert and active.
The blood level of methanethiol that best separated the group of rats that became comatose from those that did not, was approximately 0.5 nanomole per milliliter.
Applicant's summary and conclusion
- Executive summary:
In 1974, Zieve et al. reported on the "coma-producing" properties of methanethiol. Male rats, weighing 285-325 g, were exposed singly for up to 15 minutes to methanethiol at concentrations of approximately 600-2,200 ppm (1,182-4,334 mg/cu m). Three to eight rats were exposed at each concentration. For static exposures, the desired thiol concentrations were achieved by injecting the required amount of thiol through a rubber septum in the lid of the chamber into which the rat had been placed. Occasional analysis of chamber air showed that actual concentrations varied by 5% at a 1%-by-volume (10,000 ppm) concentration and by less than 25% at the 0.1%-by-volume (1,000 ppm) concentration. For the determination of dose-response relationships, the animals were observed until they had completely lost the righting reflex or until they had been exposed to the thiol for 15 minutes. The concentration of thiol in the blood was determined after a 4-minute exposure.
The thiol concentration at which 50% of the rats lost their righting reflex was 1,600 ppm (3,152 mg/cu m) for methanethiol. The rats went through a brief excitement period before they became "groggy and lethargic," and then their righting reflex was lost within the next few minutes. The duration of the phase of excitement and beginning depression varied inversely with the concentration of the thiol inhaled. Methanethiol at 2,000 ppm (3,940 mg/cu m) caused all rats to lose their righting reflex, whereas 1,200 ppm (2,364 mg/cu m) was the highest concentration at which no animal lost the righting reflex. If the animals were removed from the chamber immediately after losing the righting reflex, "consciousness" was regained within 30 minutes. How consciousness was determined was not stated in the publication. The ratio of the concentration of thiol in the blood to that inhaled was determined. Rats exposed to methanethiol at an air concentration of 0.066 millimole/liter had blood levels of the substance that ranged from 0 to 0.5 millimole methanethiol/ml blood. From the data presented, no dose-response relationship could be determined.
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.