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EC number: 201-222-2 | CAS number: 79-74-3
- 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
Description of key information
Acute oral toxicity of 2,5-Di-t-pentylhydroquinone was tested in one study with male and female rats. In addition, acute dermal toxicity of 2,5-Di-t-pentylhydroquinone was tested in one study with male and female rabbits.
Key value for chemical safety assessment
Acute toxicity: via oral route
Link to relevant study records
- Endpoint:
- acute toxicity: oral
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1974
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: The study is not performed under GLP conditions, used methods and results are preliminary documented.
- Reason / purpose for cross-reference:
- reference to same study
- Qualifier:
- no guideline followed
- Principles of method if other than guideline:
- Rats were administered 1260, 1580, 2000, 2510, 3160 mg/kg bw Santovar A in corn oil as single oral dose and were observed for 14 days.
- GLP compliance:
- not specified
- Test type:
- standard acute method
- Limit test:
- no
- Species:
- rat
- Strain:
- Sprague-Dawley
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- no information provided
- Route of administration:
- oral: unspecified
- Vehicle:
- corn oil
- Doses:
- 1260, 1580, 2000, 2510, 3160 mg/kg bw Santovar A
- No. of animals per sex per dose:
- 3 or 2
- Control animals:
- no
- Details on study design:
- - Duration of observation period following administration: 14 days
- Other examinations performed: clinical signs, body weight - Key result
- Sex:
- male/female
- Dose descriptor:
- LD50
- Effect level:
- 1 900 mg/kg bw
- 95% CL:
- > 1 800 - < 2 000
- Mortality:
- Yes
- Clinical signs:
- other: Reduced appetite and activity, increasing weakness, collapse, and death.
- Gross pathology:
- Hemorrahagic areas of the lungs, slight liver hyperemia, and acute gastrointestinal inflammation.
- Other findings:
- none
- Interpretation of results:
- sligthly toxic
- Remarks:
- Migrated information Criteria used for interpretation of results: not specified
- Conclusions:
- A study in rats suggested that Santovar was slightly toxic, an oral LD50 of 1900 mg/kg bw was reported. The study was not performed according to the general guidelines for acute oral toxicity under GLP conditions and was very poorly documented. Therefore, the information may be considered reliable with major restrictions.
Reference
Endpoint conclusion
- Endpoint conclusion:
- adverse effect observed
- Dose descriptor:
- LD50
- Value:
- 1 900 mg/kg bw
Acute toxicity: via inhalation route
Endpoint conclusion
- Endpoint conclusion:
- no study available
Acute toxicity: via dermal route
Link to relevant study records
- Endpoint:
- acute toxicity: dermal
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1974
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: The study is not performed under GLP conditions, used methods and results are preliminary documented.
- Reason / purpose for cross-reference:
- reference to same study
- Qualifier:
- no guideline followed
- Principles of method if other than guideline:
- Rats were exposed to 2000, 3160, 5010, 7940 mg/kg bw Santovar A in corn oil during 24 hours and were observed for 14 days.
- GLP compliance:
- not specified
- Test type:
- standard acute method
- Species:
- rabbit
- Strain:
- New Zealand White
- Sex:
- male/female
- Type of coverage:
- not specified
- Vehicle:
- corn oil
- Duration of exposure:
- 24 hours
- Doses:
- 2000, 3160, 5010, 7940 mg/kg bw Santovar A
- No. of animals per sex per dose:
- 1 or 2 at highest dose
- Control animals:
- no
- Key result
- Sex:
- male/female
- Dose descriptor:
- LD50
- Effect level:
- > 3 160 mg/kg bw
- Mortality:
- Yes, at 5010 and 7940 mg/kg bw after 4 and 5 days, resp.
- Clinical signs:
- other: Reduced appetite and activity, increasing weakness, collapse, and death.
- Gross pathology:
- Lung and liver hyperemia, enlarged gall bladder, and gastrointestinal inflammation.
- Other findings:
- none
- Interpretation of results:
- sligthly toxic
- Remarks:
- Migrated information Criteria used for interpretation of results: not specified
- Executive summary:
- A study in rabbits suggested that Santovar was slightly toxic, a dermal LD50 of > 3160 mg/kg bw was reported. The study was not performed according to the general guidelines for dermal toxicity under GLP conditions and was very poorly documented. Therefore, the information may be considered reliable with major restrictions.
Reference
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- LD50
- Value:
- 3 160 mg/kg bw
Additional information
The studies were not performed according to the general guidelines for acute oral/dermal toxicity testing neither performed under GLP-conditions and were documented poorly. Therefore, the data should be considered as indicative only. Upon oral administration of 2,5-Di-t-pentylhydroquinone to rats an LD50 of 1900 mg/kg bw is reported and upon dermal administration of 2,5-Di-t-pentylhydroquinone to rabbits an LD50 of > 3160 mg/kg bw is reported.
Justification for classification or non-classification
Based on the above mentioned results, the substance shall be classified for acute toxicity with R22 according to Dangerous Substance Directive 67/548/EC and Acute tox 4 according to CLP Regulation (EC) 1272/2008.
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