You create a spherical area of clean, breathable air centered on a point within range for the duration. The sphere can have any radius you choose to a maximum of 30 feet. If the point you choose is on an object you are holding or one that isn't being worn or carried, the sphere is centered on the object and moves with it. Airborne substances such as poisonous gas, smoke, or fog can't enter the sphere, and any such substances already within the sphere's area are destroyed. If such a substance is created by a spell of a higher level than this one, it is
unaffected. The area’s temperature is comfortable, regardless of the outside environment.

***From Dark Matters***