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Diss Factsheets
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EC number: 201-193-6 | CAS number: 79-29-8
- 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
![](https://echa.europa.eu./o/diss-blank-theme/images/factsheets/A-REACH/factsheet/print_toxicological-information.png)
Repeated dose toxicity: oral
Administrative data
- Endpoint:
- short-term repeated dose toxicity: oral
- Type of information:
- experimental study
- Adequacy of study:
- supporting study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: see 'Remark'
- Remarks:
- This study is classified as reliable with restrictions even though it is not noted whether the study followed GLPs and was not conducted in accordance with guidelines. This is because the study’s goal was to examine nephrotoxicity, not systemic toxicity as outlined in OECD guideline 407. Study methods are well-documented and scientifically sound.
- Justification for type of information:
- A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.
Cross-referenceopen allclose all
- Reason / purpose for cross-reference:
- read-across: supporting information
Reference
- Endpoint:
- short-term repeated dose toxicity: oral
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- supporting study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: see 'Remark'
- Remarks:
- This study is classified as reliable with restrictions even though it is not noted whether the study followed GLPs and was not conducted in accordance with guidelines. This is because the study’s goal was to examine nephrotoxicity, not systemic toxicity as outlined in OECD guideline 407. Study methods are well-documented and scientifically sound.
- Justification for type of information:
- A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.
- Reason / purpose for cross-reference:
- read-across source
- Reason / purpose for cross-reference:
- reference to same study
- Clinical signs:
- effects observed, treatment-related
- Mortality:
- mortality observed, treatment-related
- Body weight and weight changes:
- effects observed, treatment-related
- Food consumption and compound intake (if feeding study):
- not examined
- Food efficiency:
- not examined
- Water consumption and compound intake (if drinking water study):
- not examined
- Ophthalmological findings:
- not examined
- Haematological findings:
- not examined
- Clinical biochemistry findings:
- not examined
- Urinalysis findings:
- not examined
- Behaviour (functional findings):
- not examined
- Organ weight findings including organ / body weight ratios:
- no effects observed
- Gross pathological findings:
- no effects observed
- Histopathological findings: non-neoplastic:
- no effects observed
- Histopathological findings: neoplastic:
- not examined
- Details on results:
- MORTALITY
10% of low dose rats, 90% of high dose rats
TERMINAL BODY WEIGHT
significantly lower than saline control at the low dose (p < 0.05), not calculated at high dose due to high mortality
KIDNEY WEIGHTS
not significantly different than controls at low dose, not calculated at high dose due to high mortality
GROSS PATHOLOGY
no effects
HISTOPATHOLOGY: KIDNEY
not significantly different than controls at low dose, not calculated at high dose due to high mortality - Dose descriptor:
- NOAEL
- Remarks on result:
- not determinable
- Remarks:
- no NOAEL identified
- Critical effects observed:
- not specified
- Conclusions:
- The results for 2-methylbutane and saline (i.e., the control) were not significantly different. 2-methylbutane was found to cause high mortality at 2.0 g/kg/day.
- Executive summary:
This data is being read across from the source study that tested 2-methylbutane based on analogue read across.
The nephrotoxicity of 2-methylbutane was evaluated in male F344 rats over 4 weeks after oral gavage doses of 0.5 g/kg/day and 2.0 g/kg/day. Clinical examinations were conducted twice daily throughout the study, and nephrotoxicity and histopathology of the kidney were evaluated at termination. The results were compared to positive and negative controls. Statistical methods used were appropriate.
Mortality occurred in 90% of high-dose rats and 10% of low-dose rats. Kidney weights for surviving animals were comparable to controls. 2 -methylbutane's ability to cause hydrocarbon nephropathy was comparable to the saline control (not significantly different).
This study is classified as reliable with restrictions, Klimisch score 2, even though it is not noted whether the study followed GLPs and was not conducted in accordance with guidelines. This is because the study’s goal was to examine nephrotoxicity, not systemic toxicity as outlined in OECD guideline 407. Study methods are well-documented and scientifically sound. However, several study limitations are noted when comparing this study’s methods to OECD 407. First, no female rats were used in the study. Second, the selected dose levels did not cover an appropriate range (i.e., only two dose groups were used, and both were at fairly high doses for a substance that can be aspirated). Third, the substance was administered 5 days/week instead of 7. Fourth, body weight measurements were only taken twice during the experiment (i.e, prior to dosing and at the scheduled sacrifice). Fifth, the only post-necropsy examinations were of the kidney. Finally, functional observations, hematology analysis, urinalysis and other post-necropsy examinations were were conducted.
- Reason / purpose for cross-reference:
- reference to same study
Data source
Reference
- Reference Type:
- publication
- Title:
- Unnamed
- Year:
- 1 985
Materials and methods
Test guideline
- Qualifier:
- no guideline followed
- Principles of method if other than guideline:
- The study’s goal was to examine nephrotoxicity, not systemic toxicity as outlined in OECD guideline 407. When comparing the study's methods to OECD 407, the following limitations were noted: no female rats were tested; only two dose groups were tested at fairly high doses for a substance that can be aspirated; the only post-necropsy examinations were of the kidney.
- GLP compliance:
- not specified
- Limit test:
- no
Test material
- Reference substance name:
- 2-methylbutane
- EC Number:
- 201-142-8
- EC Name:
- 2-methylbutane
- Cas Number:
- 78-78-4
- Molecular formula:
- C5H12
- IUPAC Name:
- 2-methylbutane
- Details on test material:
- - Name of test material (as cited in study report): 2-methylbutane
- Substance type: C5 aliphatics
- Analytical purity: not reported
Constituent 1
Test animals
- Species:
- rat
- Strain:
- Fischer 344
- Sex:
- male
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River Breeding Laboratories, Kingston, New York
- Age at study initiation: 9 weeks
- Weight at study initiation: 171 to 194 grams
- Fasting period before study: not reported
- Housing: individual, suspended polycarbonate cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 2 weeks
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 to 26 degrees celsius
- Humidity (%): 40 to 80 %
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 12 hours dark and 12 hours light
Administration / exposure
- Route of administration:
- oral: gavage
- Vehicle:
- unchanged (no vehicle)
- Details on oral exposure:
- PREPARATION OF DOSING SOLUTIONS: calculated based on body weights taken prior to dosing on day 1, appropriate dosing volume was determined using specific gravity
- Analytical verification of doses or concentrations:
- not specified
- Duration of treatment / exposure:
- 4 weeks
- Frequency of treatment:
- once daily, 5 days per week
Doses / concentrationsopen allclose all
- Remarks:
- Doses / Concentrations:
0.5 g/kg/day
Basis:
no data
- Remarks:
- Doses / Concentrations:
2.0 g/kg/day
Basis:
no data
- No. of animals per sex per dose:
- 10
- Control animals:
- yes
- Details on study design:
- - Dose selection rationale: pilot study
- Negative control: isotonic saline at a dose of 2.0 g/kg/day - Positive control:
- Unleaded gasoline
Examinations
- Observations and examinations performed and frequency:
- CAGE SIDE OBSERVATIONS: yes
- Time schedule: twice daily
DETAILED CLINICAL OBSERVATIONS: yes
- Time schedule: twice daily
BODY WEIGHT: yes
- Time schedule for examinations: prior to dosing and at scheduled sacrifice
FOOD EFFICIENCY: not reported
WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): no
OPHTHALMOSCOPIC EXAMINATION: no
HAEMATOLOGY: no
CLINICAL CHEMISTRY: no
URINALYSIS: no
NEUROBEHAVIOURAL EXAMINATION: no - Sacrifice and pathology:
- GROSS PATHOLOGY: yes (stated, no data provided)
HISTOPATHOLOGY: yes (kidney only) - Statistics:
- mean and standard deviations calculated for body weight, kidney weight, and kidney pathology data; statistical significance calculated using Studen t-test and Mann-Whitney U test
Results and discussion
Results of examinations
- Clinical signs:
- effects observed, treatment-related
- Mortality:
- mortality observed, treatment-related
- Body weight and weight changes:
- effects observed, treatment-related
- Food consumption and compound intake (if feeding study):
- not examined
- Food efficiency:
- not examined
- Water consumption and compound intake (if drinking water study):
- not examined
- Ophthalmological findings:
- not examined
- Haematological findings:
- not examined
- Clinical biochemistry findings:
- not examined
- Urinalysis findings:
- not examined
- Behaviour (functional findings):
- not examined
- Organ weight findings including organ / body weight ratios:
- no effects observed
- Gross pathological findings:
- no effects observed
- Histopathological findings: non-neoplastic:
- no effects observed
- Histopathological findings: neoplastic:
- not examined
- Details on results:
- MORTALITY
10% of low dose rats, 90% of high dose rats
TERMINAL BODY WEIGHT
significantly lower than saline control at the low dose (p < 0.05), not calculated at high dose due to high mortality
KIDNEY WEIGHTS
not significantly different than controls at low dose, not calculated at high dose due to high mortality
GROSS PATHOLOGY
no effects
HISTOPATHOLOGY: KIDNEY
not significantly different than controls at low dose, not calculated at high dose due to high mortality
Effect levels
- Dose descriptor:
- NOAEL
- Remarks on result:
- not determinable
- Remarks:
- no NOAEL identified
Target system / organ toxicity
- Critical effects observed:
- not specified
Applicant's summary and conclusion
- Conclusions:
- The results for 2-methylbutane and saline (i.e., the control) were not significantly different. 2-methylbutane was found to cause high mortality at 2.0 g/kg/day.
- Executive summary:
The nephrotoxicity of 2-methylbutane was evaluated in male F344 rats over 4 weeks after oral gavage doses of 0.5 g/kg/day and 2.0 g/kg/day. Clinical examinations were conducted twice daily throughout the study, and nephrotoxicity and histopathology of the kidney were evaluated at termination. The results were compared to positive and negative controls. Statistical methods used were appropriate.
Mortality occurred in 90% of high-dose rats and 10% of low-dose rats. Kidney weights for surviving animals were comparable to controls. 2 -methylbutane's ability to cause hydrocarbon nephropathy was comparable to the saline control (not significantly different).
This study is classified as reliable with restrictions, Klimisch score 2, even though it is not noted whether the study followed GLPs and was not conducted in accordance with guidelines. This is because the study’s goal was to examine nephrotoxicity, not systemic toxicity as outlined in OECD guideline 407. Study methods are well-documented and scientifically sound. However, several study limitations are noted when comparing this study’s methods to OECD 407. First, no female rats were used in the study. Second, the selected dose levels did not cover an appropriate range (i.e., only two dose groups were used, and both were at fairly high doses for a substance that can be aspirated). Third, the substance was administered 5 days/week instead of 7. Fourth, body weight measurements were only taken twice during the experiment (i.e, prior to dosing and at the scheduled sacrifice). Fifth, the only post-necropsy examinations were of the kidney. Finally, functional observations, hematology analysis, urinalysis and other post-necropsy examinations were were conducted.
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.
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