He wasn't impervious to harm, much as he might think so.
In their poetry above everything the Japanese have remained impervious to alien influences.
He clasped his arms behind his head and lay down, impervious to the cold.
Jarrah timber is nearly impervious to the attacks of the teredo, and there is good evidence to show that, exposed to wear and weather, or placed under the soil, or used as submarine piles, the wood remained intact after nearly fifty years' trial.
Membranes which allow a solvent to pass freely but are impervious to a solute when dissolved in that solvent.