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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 202-603-6 | CAS number: 97-72-3
Toxicity to microorganisms
Administrative data
Link to relevant study record(s)
Description of key information
Isobutyric acid inhibited the cell growth of Tetrahyma pyriformis test cultures by 50 % at a concentration of 2.15 mg/mL.
Key value for chemical safety assessment
- EC50 for microorganisms:
- 2.15 mg/L
Additional information
Hydrolysis studies show that isobutyric anhydride added to water rapidly converts to isobutyric acid. Thererfore, isobutyric acid data is being used by read across for most environmental fate and ecotox endpoints.
From three tests identified, only one test is valid (Schulz, 1997). The documentation of the other two (BASF AG, 1989; Hoechst AG 1979) is insufficient for assessment.
Schulz 1997
In a valid 40 hour growth inhibition study, test cultures of the cilliate Tetrahymena pyriformis were exposed to isobutyric acid at five graduate concentrations under static conditions (individual concentrations not reported). The assay was performed in three independent replicate runs on the basis of a preceding range finding test.
The IC50 value based on cell density was determined to be 2.15 mg/L indicating low to moderate toxicity of isobutyric acid to aqueous microorganisms (cilliates) (Schultz, 2006).
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.
