Respiratory irritants are substances which can cause inflammation or other adverse reactions in the respiratory system (lungs, nose, mouth, larynx and trachea) after being inhaled. Depending on the type and amount of irritant gas inhaled, victims can experience symptoms ranging from minor respiratory discomfort to acute airway and lung injury and even death. The lungs are susceptible to many airborne irritants. A common response cascade to a variety of irritant gases includes inflammation, edema and epithelial sloughing which, left untreated, can result in scar formation and pulmonary and airway remodeling. There are hundreds of substances that can pollute air and harm lungs. Harmful gases and chemicals are just one type of airborne pollutants that can adversely affect the lungs. Examples of respiratory irritants include, for example, chlorine, amonium, ozone, sulphur dioxide or nitrogen oxides. These substances, their sources of exposure, physical and other properties, and effects on the victim are summarized in this article.

Keywords: respiratory irritants; irritant gases; inflammation; chlorine; hydrogen chloride; hydrogen fluoride; hydrogen sulfide; sulphur dioxide; nitrogen dioxide; ammonia; ozone