Aura of Purity (Su): The witch’s aura purifies the air around her. Diseases, inhaled poisons, and noxious gaseous effects (such as stinking cloud) are negated in a 10-foot aura around the witch for a number of minutes equal to her level. This duration does not need to be consecutive, but it must be spent in 1-minute increments. Effects caused by spells whose level is more than half the witch’s class level are unaffected.