The term ‘superheated water’ usefully refers to liquid water under pressure between 100oC and its critical temperature, 374oC.

It is much less polar than water at ambient temperatures and can dissolve organic compounds, particularly if they are polarisable or slightly polar.

It can therefore be used as an alternative to organic solvents for environmentally friendly processes, avoiding residues in the products, such as extraction, liquid fractionation, chromatography and decontamination.