Quartz and Pyrex are attacked by the compound at higher temperatures.

As a dihydrate, it is a colourless, hygroscopic, crystalline solid that is waxy in nature.

[1] It reacts with phosphorus trifluoride to form protactinium(IV) fluoride.

[3] The dihydrate cannot be converted into the anhydrous form in air, hydrogen fluoride or fluorine at low temperatures.

At higher temperatures around 325 °C, a mixture of the diprotactinium(V) oxide octafluoride and protactinium(V) fluoride is formed.