I'm reading Introduction to Electrodynamics by Griffiths and in chapter 4 when discussing induced dipoles and the effect of an electric field on an electrical insulator, it says the following:
These two regions of charge within the atom (positively charged nucleus and negatively charge electron cloud) are influenced by the field: the nucleus is pushed in the direction of the field, and the electrons the opposite way. In principle, if the field is large enough, it can pull the atom apart completely, "ionizing" it (the substance then becomes a conductor).
Emphasis mine and italicized comment added for clarity. I know it says in principle, indicating that this does not happen, but is it possible to ionize an insulator, say wood, with an extremely strong electric field? If it is theoretically possible, how strong would the electric field have to be in order for this to happen (orders of magnitude would be fine)? What would happen to a piece of wood in this kind of electric field? If it is not possible, is it due to limitations on the strength of electric field that we can actually create?