Inhalation of irritant gases, vapors, fumes, and particulates occurs in industry, agriculture, homes, and in structural fires. Acute responses to irritants can include rhinoconjunctivitis, pharyngitis, laryngospasm, bronchospasm, chemical bronchitis, and chemical pneumonitis. Subacute/chronic sequelae may include irritant rhinitis/sinusitis, irritant-induced asthma, irritant-associated vocal cord dysfunction, odor-triggered panic attacks, and bronchiolitis obliterans. Overlapping presentations, particularly for disorders producing episodic dyspnea in the workplace, can pose difficulties in the differential diagnosis. Similarities and differences in clinical presentation are reviewed in this article, as well as the importance of integrating psychosocial dynamics into the medical workup.