Iowa Code § 455B.135: Limit on authority.

Nothing contained in this subchapter II or chapter 459, subchapter II, shall be deemed to grant to the department or the director any authority or jurisdiction with respect to air pollution existing solely within residences; or solely within commercial and industrial plants, works, or shops under the jurisdiction of chapter 10A, subchapter II, and chapter 88; or to affect the relations between employers and employees with respect to, or arising out of, any condition of air pollution.