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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 231-901-9 | CAS number: 7778-39-4
Adsorption / desorption
Administrative data
Link to relevant study record(s)
Description of key information
The information requirement on Koc is waived since arsenic acid is an inorganic compound of arsenic. Partitioning coefficients Kp are determined according to values originating from a RIVM report.
Key value for chemical safety assessment
Additional information
In the case of inorganic substances the use of Kow and Koc to estimate the partitioning between media is not applicable. The sorption of arsenic is considered to be controlled by arsenic oxidation state and depend on prevailing environmental conditions such as metal oxides (iron, aluminium), clay, organic matter. Therefore, the adsorption/desorption between the aqueous phase and the relevant compartments (suspended matter, sediment and soil) need to be described by partitioning coefficients (Kpcomp). Such partitioning coefficients have been identified in a RIVM Report and are proposed to be used for the purpose of the chemical safety assessment of the registered substance.
RIVM Report:
Crommentuijn T, Polder M. and Van de Plassche, E 1997. Maximum permissible concentrations and negligible concentrations for metals, taking background concentrations into account. RIVM, Report 601501001.
Other adsorption coefficient indicated as dimensionless:
- log Kp (solids-water in soil) ,2.28
- log Kp (solids-water in sediment) ,3.82
- log Kp (solids-water in suspended matter) ,4.0
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.
