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Description of key information

In accordance with the Guidance on Information Requirements and Chemical Saftey Assessment, chapter R.7c (ECHA, 2008) the profile on basic toxicokinetics of cesium iodide was derived from physico-chemical data as well as from toxicological data of CsI and structurally related cesium salts.
Due to its physico-chemical properties and the observed systemic toxicity at least at high concentrations of cesium compounds CsI more precisely the two respective ions will be well absorbed within the GI tract and become bioavailable following oral administration. This estimation is confirmed by literature data.
Based on its physico-chemical properties and absence of toxicity in an acute dermal toxicity study very limited absorption into the systemic circulation is expected after dermal application. Literature data support this estimation.
Considering the very low vapour pressure, the resulting low volatility and the fact that the chemical exist as a crystalline solid at room temperature with particle sizes well above 100 μm it is unlike that the substance will be inhaled either in vapour form or as dust particles under use conditions.
Based on the physico-chemical properties of cesium ions are readily distributed throughout the body. This is confirmed by the presence of target organs in subacute and subchronic studies and literature data. In addition, iodide is mainly actively transported into the thyroid gland.
Due to the physico-chemical properties and according to available literature it is not likely that cesium ions will undergo further enzymatic biotransformation processes or will reveal an accumulation potential.
Iodide is actively transported into the thyroid follicle by the sodium iodine symporter and then oxidised to molecular iodine. Thus, 70 – 90 % of the iodine in the body accumulates in the thyroid gland, which produces iodine containing thyroid hormones.
Considering the physico-chemical properties and the available literature CsI is mainly urinary excreted.

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential

Additional information