Registration Dossier

Environmental fate & pathways

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 be0 due to its salt character and high water solubility.