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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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.

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Environmental fate & pathways

Henry's Law constant

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Description of key information

Henry's Law Constant [4,4,7,7-tetraethoxy-3,8-dioxa-4,7-disiladecane]: Calculated HLC at environmental temperature (12°C): 3.6 Pa m3mol-1

Henry's Law Constant [ 1,1,1,4,4,4-hexahydroxy-1,4-silabutane]: Calculated HLC at 25°C: 1.3E-17 Pa m3mol-1

Key value for chemical safety assessment

Henry's law constant (H) (in Pa m³/mol):
at the temperature of:
12 °C

Additional information

The transfer of a substance from the water phase to the gas phase can be estimated by means of the Henry’s Law Constant (HLC). No measured value for this parameter is available. The HLC can be estimated from the ratio of the vapour pressure (VP) to the water solubility (WS).

HLC = (VP x MW)/WS

Where MW is molecular weight.

The calculated HLC value for the registered substance at environmental temperature (12°C) is 3.6 Pa m3mol-1 (taken from EUSES 2.1.2, though please note the environmental exposure assessment is conducted in CHESAR 3.0).

In contact with water, the substance hydrolyses moderately to form 1,1,1,4,4,4-hexahydroxy-1,4-silabutane and ethanol.

For the silanol hydrolysis product, the predicted water solubility limit cannot be validated accurately due to condensation phenomena. The HLC can be estimated using the established Bond method from HENRYWIN v3.20 within the EPI Suite v4.11. This method derives the Henry's Law Constant directly from the structure and has been validated for this structural type. The calculated HLC value for the silanol hydrolysis product at 25°C is very low, 1.3E-17 Pa m3mol-1.