A vast number of compounds produce irritant effects when inhaled in the gaseous form. The most common source of exposure to irritant gases is industry, but significant exposures may occur in a variety of circumstances, such as after mixing cleaning agents at home, with smoke inhalation in structural fires, or after highway tanker spills.
Mechanism of toxicity. Irritant gases often are divided into two major groups on the basis of their water solubility (Table II–29).
Table II-29 Irritant Toxic Gases |Favorite Table|Download (.pdf)
Table II-29 Irritant Toxic Gases
High water solubility
Moderate water solubility
Low water solubility
Highly soluble gases (eg, ammonia and chlorine) are readily adsorbed by the upper respiratory tract and rapidly produce their primary effects on moist mucous membranes in the eyes, nose, and throat.
Less soluble gases (eg, phosgene and nitrogen dioxide) are not rapidly adsorbed by the upper respiratory tract and can be inhaled deeply into the lower respiratory tract to produce delayed-onset pulmonary toxicity.
Toxic dose. The toxic dose varies with the properties of the gas. Table II–29 illustrates the workplace exposure limits (TLV-TWA) and the levels immediately dangerous to life or health (IDLH) for several common irritant gases.
Clinical presentation. All these gases may produce irritant effects to the upper and/or lower respiratory tract, but warning properties and the onset and location of primary symptoms depend largely on the water solubility of the gas and the concentration of exposure.
Highly soluble gases. Because of the good warning properties (upper respiratory tract irritation) of highly soluble gases, voluntary prolonged exposure to even low concentrations is unlikely.
Low-level exposure causes rapid onset of mucous membrane and upper respiratory tract irritation; conjunctivitis, rhinitis, skin erythema and burns, sore throat, cough, wheezing, and hoarseness are common.
With high-level exposure, laryngeal edema, tracheobronchitis, and abrupt airway obstruction may occur. Irritation of the lower respiratory tract and lung parenchyma causes tracheobronchial mucosal sloughing, chemical pneumonitis, ...