Registration Dossier
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EC number: 204-145-2 | CAS number: 116-53-0
- 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

Acute Toxicity: dermal
Administrative data
- Endpoint:
- acute toxicity: dermal
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study with acceptable restrictions
Cross-referenceopen allclose all
- Reason / purpose for cross-reference:
- reference to same study
Reference
- Endpoint:
- acute toxicity: oral
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study with acceptable restrictions
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 401 (Acute Oral Toxicity)
- GLP compliance:
- not specified
- Limit test:
- no
- Species:
- rat
- Strain:
- Sprague-Dawley
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Weight at study initiation: 200 - 300 g
- Fasting period before study: overnight
- Diet: standard lab diet ad libitum
- Water: ad libitum - Route of administration:
- oral: gavage
- Vehicle:
- unchanged (no vehicle)
- Details on oral exposure:
- MAXIMUM DOSE VOLUME APPLIED: 4 mL/kg bw
- Doses:
- males: 1.0, 2.0, 4.0 mL/kg bw
females: 0.25, 0.5, 1.0, 2.0, 4.0 mL/kg bw - No. of animals per sex per dose:
- 5
- Control animals:
- no
- Details on study design:
- - Duration of observation period following administration: 14 days
- Frequency of observations and weighing: on days 0 (prior to treatment), 7, and 14
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight - Statistics:
- LD50 value was calculated using the moving average method (Thompson, 1947; Weil, 1983)
- Key result
- Sex:
- male/female
- Dose descriptor:
- LD50
- Effect level:
- 1 750 mg/kg bw
- Based on:
- test mat.
- Remarks on result:
- other: Using a density of 0.936 kg/L, the calculated LD50 of 1.87 mL/kg bw is equivalent to 1750 mg/kg bw
- Mortality:
- Most deaths occurred at 1.5 to 2 days. However, three females died at 10 to 14 days. Survivors recovered at one to three days.
Males: 0/5, 3/5 and 5/5 of the low, middle and high dose group died
Females: 0/5, 0/5, 1/5, 2/5, 5/5 of the 0.25, 0.5, 1, 2, 4 mL/kg bw dose group died, respectively - Clinical signs:
- Signs of toxicity included sluggishness, lacrimation, unkempt fur, kyphosis (in 2), prostration, a moribund appearance, diarrhea, red to brown discharge on perioral, perinasal and periurogenital fur.
- Body weight:
- Males: body weight gain at 1.0 mL/kg bw; bodyw eight reduced at 2.0 mL/kg bw
Females: no body weight gain at all dose levels - Gross pathology:
- Dead animals: stomach abnormalities (discoloration, brown liquid or gas, gastric collapse); discoloure dlungs; brown to dark red livers, intstines, and kidneys.
Survivors: small stomachs and spleens; rough stomach surfaces, adhesion of the stomach to liver or spleen, enlarged and mottled red kidneys. - Interpretation of results:
- Category 4 based on GHS criteria
- Conclusions:
- The LD50 was 1750 mg/kg bw in male and female rats. Necropsy findings in survivors revealed irritation/corrosion of the stomach and intestines.
- Executive summary:
Oral toxicity was investigated in a study similar to OECD TG 401. Male and female rats (n=5 per sex per dose) were exposed against different doses of test substance up to 4 mL/kg bw (3744 mg/kg bw by calculation on basis of substance density of 0.936 kg/L). Exposed animals showed signs of toxicity including sluggishness, lacrimation, unkempt fur, kyphosis, prostration, a moribund appearance, diarrhea, red to brown discharge on perioral, perinasal and periurogenital fur. Female rats of all dose groups and male rats at doses >= 2 mL/kg bw did not gain body weight. The following findings were observed at necropsy of dead animals: stomach abnormalities (discoloration, brown liquid or gas, gastric collapse), discoloured lungs, brown to dark red livers, intstines, and kidneys. Necropsy of the surving animals revealed the following effects: small stomachs and spleens; rough stomach surfaces, adhesion of the stomach to liver or spleen, enlarged and mottled red kidneys.Using the moving average method an LD50 value of 1.87 mL/kg bw (corresponding to 1750 mg/kg bw) was calculated for male and female rats.
- Reason / purpose for cross-reference:
- reference to same study
Reference
- Endpoint:
- acute toxicity: inhalation
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study with acceptable restrictions
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 403 (Acute Inhalation Toxicity)
- Principles of method if other than guideline:
- Inhalation Risk Test
- GLP compliance:
- not specified
- Test type:
- fixed concentration procedure
- Limit test:
- yes
- Species:
- rat
- Strain:
- Sprague-Dawley
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Weight at study initiation: 200 - 300 g - Route of administration:
- inhalation: vapour
- Type of inhalation exposure:
- whole body
- Vehicle:
- air
- Details on inhalation exposure:
- GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: animal chmaber
- Exposure chamber volume: 100 to 152 L
- Method of holding animals in test chamber: in cage
- Source and rate of air: air in the exposure chamber
- System of generating atmosphere: 100 g of the test material was placed in the sealed exposure chamber for approx. 18 hours. A mixing fan periodically agitated the chamber atmosphere to aid in distribution of the vapour. Oxgen was added, as needed, to maintain approx. 20% of oxygen. - Analytical verification of test atmosphere concentrations:
- not specified
- Duration of exposure:
- 6 h
- Concentrations:
- saturation
- No. of animals per sex per dose:
- 5
- Control animals:
- no
- Details on study design:
- - Duration of observation period following administration: 14 days
- Frequency of observations and weighing: on days 0 (prior to treatment), 7, and 14
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight - Statistics:
- none
- Key result
- Sex:
- male/female
- Dose descriptor:
- LC0
- Effect level:
- 8 375 mg/m³ air (nominal)
- Based on:
- test mat.
- Exp. duration:
- 6 h
- Remarks on result:
- other: There were no signs of toxicity and no gross lesions at necropsy.
- Mortality:
- No death during exposure or thereafter
- Clinical signs:
- other: None noted
- Body weight:
- Increase in males from 280 g on day 0 to 339 g on day 14. No significant body weight gain in females (237 g before treatment, 244 g at day 14 (all values means).
- Gross pathology:
- No gross lesions noted
- Interpretation of results:
- GHS criteria not met
- Conclusions:
- Male and female rats (5 per sex) survived a 6-hour whole body exposure to a saturated vapour atmosphere. There were no deaths within the 14-day observation period. There were no clinical signs of toxicity at any time, or gross lesions at terminal sacrifice. According to EC/1272/2008 table 3.1.1 the substance is not acutely toxic after inhalation.
- Executive summary:
Male and female rats (5 per sex) survived a 6-hour whole body exposure to a saturated vapour atmosphere. There were no deaths within the 14-day observation period. There were no clinical signs of toxicity at any time, or gross lesions at terminal sacrifice.
- Reason / purpose for cross-reference:
- reference to same study
Reference
- Endpoint:
- skin irritation: in vivo
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Similar to guideline study
- Reason / purpose for cross-reference:
- reference to same study
- Reason / purpose for cross-reference:
- reference to same study
- Reason / purpose for cross-reference:
- reference to same study
- Reason / purpose for cross-reference:
- reference to same study
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
- GLP compliance:
- not specified
- Species:
- rabbit
- Strain:
- New Zealand White
- Type of coverage:
- occlusive
- Preparation of test site:
- clipped
- Vehicle:
- unchanged (no vehicle)
- Controls:
- not required
- Amount / concentration applied:
- TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL - Duration of treatment / exposure:
- 1) 4 hours and
2) 3 minutes - Observation period:
- 14 days
- Number of animals:
- 6
- Details on study design:
- TEST SITE
- Area of exposure: no data
- % coverage: no data
- Type of wrap if used: gauze patch with impervious sheeting
REMOVAL OF TEST SUBSTANCE
- Washing (if done): excess material is removed after the 4-hr or 3-min contact period
SCORING SYSTEM: Table of Draize (as in OECD 404) - Irritation parameter:
- erythema score
- Basis:
- mean
- Time point:
- other: 5 hr after skin contact
- Score:
- 1.3
- Max. score:
- 4
- Reversibility:
- not reversible
- Remarks:
- Skin necroses were seen at the 5-hr reading in 3 rabbits. Irreversible skin alterations were seen in all animals at 14 after 14 days post treatment.
- Remarks on result:
- other: 3-minute skin contact
- Irritation parameter:
- edema score
- Basis:
- mean
- Remarks:
- of 6 animals
- Time point:
- other: 5 hr after skin contact
- Score:
- 2.5
- Max. score:
- 4
- Reversibility:
- not reversible
- Remarks on result:
- other: 3-minute skin contact
- Irritant / corrosive response data:
- At the 5-hr skin examination and thereafter, skin necrosis was seen in most rabbits exposed for 3 minutes and all animals exposed for 4 hours. Full thickness necrosis was confirmed at termination. No reading was made within 1 hour after skin contact.
- Interpretation of results:
- Category 1B (corrosive) based on GHS criteria
- Conclusions:
- 2-methylbuytric acid caused full thickness skin necrosis in 5 animals after a 3-minute contact to the intact rabbit skin. Necrosis was already seen in 3 animals at the first reading at 5 hours after skin contact. The substance is at least a CAT1B skin corrosive; classification as a CAT 1A corrosive is also possible but cannot be judged because this would require a reading within one hour after the skin contact (Regulation (EC) No. 1272/2008).
- Executive summary:
Skin irritating/corrosive properties of the test item were investigated in New Zealand rabbits in a study similar to OECD TG 404. Rabbits were exposed for 3 minutes or 4 hours toward 0.5 mL of the undiluted test item and observed for up to 14 days. Full thickness skin corrosion was observed in animal after 3 minutes or 4 hour exposure and was evident already at the first reading at 5 hours after the start of the exposure.
Skin reactions after 4-hr contact period (means of 6 animals); 0.5 mL dosed
Time post | Erythema | Edema | Specific effects(selected effects)) |
5 hours | 2.0 | 4.0 | N (all animals) |
1 day | 2.5 | 4.0 | N (all animals) |
2 days | 3.0 | 4.0 | N (all animals) |
3 days | 2.8 | 4.0 | N (all animals) |
7 days | 1.0 | - | N (all animals) |
10 days | 0.3 | - | N (all animals) |
14 days | 0.0 | - | N (all animals) |
Skin reactions after a 3-minute contact period (means of 6 animals); 0.5 mL dosed
Time post | Erythema | Edema | Specific effects(selected effects) |
5 hours | 1.3 | 2.5 | N (3 animals) |
1 day | 2.3 | 3.8 | N (3 animals) |
2 days | 2.2 | 3.0 | N (4 animals) |
3 days | 0.0 | 2.3 | N (4 animals) |
7 days | 0.0 | 0.0 | N (5 animals) |
10 days | 0.0 | 0.0 | N (5 animals) |
14 days | 0.0 | 0.0 |
|
- Reason / purpose for cross-reference:
- reference to same study
Reference
- Endpoint:
- eye irritation: in vivo
- Type of information:
- experimental study
- Adequacy of study:
- other information
- Reliability:
- 3 (not reliable)
- Rationale for reliability incl. deficiencies:
- significant methodological deficiencies
- Remarks:
- Significant methological deficencies: instilled volume insufficient (0.005 mL)
- Reason / purpose for cross-reference:
- reference to same study
- Reason / purpose for cross-reference:
- reference to same study
- Reason / purpose for cross-reference:
- reference to same study
- Reason / purpose for cross-reference:
- reference to same study
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 405 (Acute Eye Irritation / Corrosion)
- Deviations:
- yes
- Remarks:
- insufficient test materila (0.005 mL)
- GLP compliance:
- not specified
- Strain:
- New Zealand White
- Vehicle:
- unchanged (no vehicle)
- Controls:
- not required
- Amount / concentration applied:
- 0.005 mL
- Duration of treatment / exposure:
- single dose
- Observation period (in vivo):
- 21 days
- Number of animals or in vitro replicates:
- 6
- Details on study design:
- SCORING SYSTEM: Darize (OECD 405)
- Irritant / corrosive response data:
- Instillation of 0.005 mL per eye resulted in moderate to severe corneal opacity in 6/6 animals. Iris was not affected and minor to severe conjunctival irritation developed in 6/6 rabbits. A purulent discharge developed after 48 hours in all animals, followed by necrosis of the nictating membrane in all animals. By day 21, 4/5 eyes appeared normal.
- Interpretation of results:
- study cannot be used for classification
- Remarks:
- Migrated information
- Conclusions:
- Under the conditions of the test the substance caused severe eye damage including necrosis.
Data source
Reference
- Reference Type:
- other: TSCAT submission
- Title:
- Unnamed
- Year:
- 1 992
- Report date:
- 1992
Materials and methods
Test guideline
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 402 (Acute Dermal Toxicity)
- GLP compliance:
- not specified
- Test type:
- standard acute method
- Limit test:
- no
Test material
- Reference substance name:
- 2-methylbutyric acid
- EC Number:
- 204-145-2
- EC Name:
- 2-methylbutyric acid
- Cas Number:
- 116-53-0
- Molecular formula:
- C5H10O2
- IUPAC Name:
- 2-methylbutanoic acid
- Test material form:
- liquid
- Details on test material:
- - Name of test material (as cited in study report): 2-methylbutyric acid
- Analytical purity: 97.9%
- Impurities (identity and concentrations): valeric acid 1.8%; unidentified 0.3%
- Stability under test conditions: shell life > 6 months
- Storage condition of test material: room temperature
Constituent 1
Test animals
- Species:
- rabbit
- Strain:
- New Zealand White
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Weight at study initiation: between 2.0 and 3.0 kg
Administration / exposure
- Type of coverage:
- occlusive
- Vehicle:
- unchanged (no vehicle)
- Details on dermal exposure:
- TEST SITE
- Type of wrap if used: occlusive
REMOVAL OF TEST SUBSTANCE
- Washing: excess fluid removed
- Time after start of exposure: 24 hr
TEST MATERIAL
- Amount(s) applied (volume or weight with unit):
males: 0.5. 1.0, 2.0, 2.83, and 4.0 mL/kg bw
females: 0.5. 1.0, 1.41, 2.0, and 4.0 mL/kg bw
- Constant volume or concentration used: no - Duration of exposure:
- 24 hr
- Doses:
- males: 0.5. 1.0, 2.0, 2.83, and 4.0 mL/kg bw (i.e. 468, 936, 1872, 2649, 3744 mg/kg bw)
females: 0.5. 1.0, 1.41, 2.0, and 4.0 mL/kg bw (i.e. 468, 936, 1320, 1872, 3744 mg/kg bw) - No. of animals per sex per dose:
- 5
- Control animals:
- not specified
- Details on study design:
- - Duration of observation period following administration: 14 days
- Frequency of observations and weighing: on days 0 (prior to treatment), 7, and 14
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, skin reactions at one hour, 7 days and 14 days after contact period. - Statistics:
- LD50 value was calculated using teh moving average method (Thompson, 1947; Weil, 1983)
Results and discussion
Effect levelsopen allclose all
- Key result
- Sex:
- male
- Dose descriptor:
- LD50
- Effect level:
- 2 228 mg/kg bw
- Based on:
- test mat.
- Remarks on result:
- other: The applied volume was converted to mg/kg bw using a density of 0.936 kg/L
- Key result
- Sex:
- female
- Dose descriptor:
- LD50
- Effect level:
- 1 367 mg/kg bw
- Based on:
- test mat.
- Remarks on result:
- other: The applied volume was converted to mg/kg bw using a density of 0.936 kg/L
- Mortality:
- Moast deaths occurred at 1.5 hours to one day; one female died at 3 days. A few affected survivors recovered after one to three days.
Males: all animals (5/5) of the two highest dose groups (4 and 2.83 mL/kg bw) died, no mortalities occurred at lower dose levels
Females: all animals (5/5) of the two highes dose groups (4 and 2 mL/kg bw) died, two animals (2/5) of the mid dose group (1.41 mL/kg bw) died, no animals died at the lower dose groups - Clinical signs:
- Local efefcts: erythema, edema, necrosis, desquamation, alopecia, ulceratins, scabs.
Sluggishness, unsteady gait, prostration, red discharge on the perinasal and perianal fur were among the signs of toxicity noted. - Body weight:
- Males: body weight gain in groups at 0.5 and 1.0 mL/kg bw; no body weight gain at 2.0 mL/kg.
Females: body weight gain in groups at 0.5 and 1.0 mL/kg bw; no body weightgain at 1.41 mL/kg bw. Complete mortality at higher dose levels. - Gross pathology:
- Findings included a few discoloured lungs; red to tan livers; grey stomachs; stomachs and/or intestines with black foci; small instetsines fileld with red liquid (in 2); dark purple or red kidneys; dark red thymuses; and bladders filled with blood.
Applicant's summary and conclusion
- Interpretation of results:
- Category 4 based on GHS criteria
- Conclusions:
- The acute dermal LD50 was 2228 mg/kg bw in male and 1367 mg/kg bw in female rabbits.Changes noted in internal organs suggest dermal absorption of the acid and irritation/corrosion of the organs.
- Executive summary:
Dermal toxicity was investigated in a study similar to OECD TG 405. Male and female white rabbits (n=5 per sex per dose) were exposed for 24 h against different doses of test substance up to 4 mL/kg bw (3744 mg/kg bw by calculation on basis of substance density of 0.936 kg/L). Exposed animals showed local effects like erythema, edema, necrosis, desquamation, alopecia, ulceratins, and scabs. Clinical sign in treated animals were sluggishness, unsteady gait, prostration, red discharge on the perinasal and perianal fur. Body weight did not increase in animals which received more than 1 mL/kg bw. At necropsy discoloured lungs, red to tan livers, grey stomachs, stomachs and/or intestines with black foci, small instetsines fileld with red liquid (in 2), dark purple or red kidneys, dark red thymuses, and bladders filled with blood were observed. The acute dermal LD50 was 2228 mg/kg bw in male and 1367 mg/kg bw in female rabbits.
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