Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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.
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: 201-195-7 | CAS number: 79-31-2
Acute Toxicity: oral
Administrative data
- Endpoint:
- acute toxicity: oral
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 20.08.1985 - 10.09.1985
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: Guideline study
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 1 985
- Report date:
- 1985
Materials and methods
Test guideline
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 401 (Acute Oral Toxicity)
- Version / remarks:
- 1981
- GLP compliance:
- no
- Test type:
- standard acute method
- Limit test:
- no
Test material
- Reference substance name:
- Isobutyric acid
- EC Number:
- 201-195-7
- EC Name:
- Isobutyric acid
- Cas Number:
- 79-31-2
- Molecular formula:
- C4H8O2
- IUPAC Name:
- 2-methylpropanoic acid
- Details on test material:
- - Name of test material (as cited in study report): Meprosan
- Physical state: liquid
- Analytical purity: >99 %
Constituent 1
Test animals
- Species:
- rat
- Strain:
- other: WISW (SPF THO)
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: F. Winkelmann, 4799 Borchen, Germany
- Weight at study initiation: male: 124 g; female: 107 g
- Fasting period before study: 16 hrs
- Housing: 1 -5 animals each cage (Makrolon Typ III)
- Diet (e.g. ad libitum): R10 Alleindiät für Ratten, Ssniff Spezialfutter GmbH, 4770 Soest, ad libidum
- Water (e.g. ad libitum): tap water, ad libidum
- Acclimation period: 4-8 days
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 +/- 1
- Humidity (%): 60 +/- 5
- Air changes (per hr): 15x
- Photoperiod (hrs dark / hrs light): 12/12
Administration / exposure
- Route of administration:
- oral: gavage
- Vehicle:
- unchanged (no vehicle)
- Details on oral exposure:
- MAXIMUM DOSE VOLUME APPLIED: 2.09 - 3.33 cm3/kg
- Doses:
- 1990, 2510, 2835, 3160 mg/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
- Animals were weighed before treatment and on day 1, 7 and 14; observations were recorded up to 6 hrs following treatment and daily thereafter.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, histopathology - Statistics:
- Determination of LD50 according to Litchfield and Wilcoxon (J. Pharmacol. Exp. Ther. 96, 1949, p. 99)
Results and discussion
Effect levels
- Sex:
- male/female
- Dose descriptor:
- LD50
- Effect level:
- 2 230 mg/kg bw
- 95% CL:
- 2 009 - 2 475
- Mortality:
- 1990 mg/kg bw: 2/5 (male), 1/5 (female) within 4 days; 2510 mg/kg bw: 3/5 (male), 5/5 (female) within 11 days
2835 mg/kg bw: 5/5 (male), 4/5 (female) within 11 days; 3160 mg/kg bw: 3/5 (male), 5/5 (female) within 4 hours - Clinical signs:
- other: 5 - 30 min after treatment, the animals showed slight to severe sedation and ataxia, lateral and prone position, labored breathing, staggering. Later on hypothermia, ruffled fur, trembling, bloody noses and snouts, and blood in the urine. Signs persist
- Gross pathology:
- Animals that died: hyperemia and distension was noted in the stomach, small intestine, and the bladder, and bloody contents were noted in these organs. Corrosion of the stomach wall was noted in some of the animals.
Animals sacrificed at termination: hyperemia, discoloring of the instestinal mucosa, swelling of the stomach mucosa was noted in some instances. Adhesions of the stomach, liver and spleen were noted in 3 survivors.
Applicant's summary and conclusion
- Interpretation of results:
- Category 4 based on GHS criteria
- Remarks:
- Migrated information Criteria used for interpretation of results: EU
- Conclusions:
- The acute oral LD50 was 2230 mg/kg bw in male and female rats in an OECD 401 study.
- Executive summary:
The acute oral toxicity was determined in a valid OECD 401 study in groups of 5 male and female rats, receiving a dose of 1990, 2510, 2835, 3160 mg/kg bw by oral gavage.
The clinical signs. i.e. sedation, ataxia, ruffled fur, hypothermia and staggering, persisted in some animals until the end of the 14-day observation period. Dead animals suffered from gastro-intestinal hemorrhage as result of the corrosive activity of the isobutyric acid.
The oral LD50 was 2230 (2009 - 2475) mg/kg bw (Hüls AG, 1985).
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.
