volatile
/ˈvɑːlətəl/ /Brit ˈv{scriptainv}ləˌtajəl/
adjective
[more ~; most ~]
likely to change in a very sudden or extreme way
having or showing extreme or sudden changes of emotion
likely to become dangerous or out of control
technical :easily becoming a gas at a fairly low temperature
noun
plural -tiles
[count] technical :a chemical or compound that changes into a gas easily