Zone of sweet air creates an invisible barrier around the area of effect that repels all noxious elements from poisonous vapors, including those created magically (such as a stinking cloud). The spell offers no protection against poisonous vapors created by a dragon's breath weapon (such as the chlorine gas of a green dragon). Noxious gases already within the area of effect when the spell is cast are not affected. Fresh air passes into the area normally.
If a poisonous vapor is expelled within the area of effect (for example, a stinking cloud is cast), the spell takes effect normally but dissipates in half the time normally required.
The spell affects a cube whose sides equal the caster's level times 10 feet (for instance, a 10th-level caster could affect a cube whose sides are 100 feet long).
The material components are the priest's holy symbol, a silk handkerchief, and a strand of spider web.