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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 244-344-1 | CAS number: 21351-79-1
Endpoint summary
Administrative data
Description of key information
Additional information
Abiotic degradation / hydrolysis
In accordance with REACH Regulation (EC) No.1907/2006 Annex XI, section 1.1.1, the performance of a test for hydrolysis as function of pH is scientifically unjustified. The study does not need to be conducted as cesium hydroxide and its anhydrous form completely dissociates in water forming a cesium cation and the corresponding hydroxide anion. The dissociation constant of cesium hydroxide monohydrate was determined to be 11.6 at 24°C.
Biotic degradation
Biodegradation in water: screening test, Biodegradation in water and sediment, Biodegradation in soil
- Biodegradation in water: screening test
In accordance with column 2 of REACH Regulation (EC) No.1907/2006, Annex VII, section 9.2.1.1 tests on biodegradation in water: screening test
do not need to be conducted as cesium hydroxide monohydrate and its anhydrous form are inorganic compounds.
- Biodegradation in water and sediment
In accordance with column 2 of REACH Regulation (EC) No.1907/2006, Annex IX , section 9.2.1.2, 9.2.1.4 and Annex XI, section 1, tests on biodegradation in water and sediment are scientifically not justified and do not need to be conducted as cesium hydroxide monohydrate and his anhydrous form are inorganic compounds which dissociate completely in water and have a low log Pow. Neither direct nor indirect exposure is expected.
- Biodegradation in soil
In accordance with column 2 of REACH Regulation (EC) No. 1907/2006, Annex IX, section 9.2.1.3, the study "biodegradation in soil" does not need to be conducted as cesium hydroxide monohydrate and the anhydrous form are inorganic compounds with a low log Pow. Also, there is neither direct nor indirect exposure of the soil compartment expected.
Bioaccumulation in aquatic/sediment
In accordance with column 2 of REACH Regulation (EC) No.1907/2006, Annex IX, section 9.3.2, the Bioconcentration Factor, BCF does not need to be determined as cesium hydroxide (anhydrous & monohydrate) is expected to have a low potential for bioaccumulation. The estimated log Pow value for cesium hydroxide anhydrous and monohydrate is expected to be ≤0 due to its salt character and high water solubility.
Transport and distribution (Adsorption/desorption)
In accordance with column 2 of REACH Regulation (EC) No. 1907/2006, Annex VIII, section 9.3.1, the test on adsorption/desorption screening does not need to be conducted, because with the physico-chemical properties of cesium hydroxide (anhydrous & monohydrate) a low adsorption potential is to be expected.
The estimated log Pow value for cesium hydroxide anhydrous and monohydrate is expected to be≤0 due to its salt character and high water solubility.
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.
