Chlorine is a heavier-than-air yellowish-green gas with an irritating odor. It is used widely in chemical manufacturing, in bleaching, and (as hypochlorite) in swimming pool disinfectants and cleaning agents. Hypochlorite is an aqueous solution produced by the reaction of chlorine gas with water; most household bleach solutions contain 3–5% hypochlorite, and swimming pool disinfectants and industrial-strength cleaners may contain up to 20% hypochlorite. The addition of acid to hypochlorite solution may release chlorine gas. The addition of ammonia to hypochlorite solution may release chloramine, a gas with toxic properties similar to those of chlorine.
Mechanism of toxicity. Chlorine gas produces a corrosive effect on contact with moist tissues, such as those of the eyes and upper respiratory tract. Exposure to aqueous solutions causes corrosive injury to the eyes, skin, or GI tract (See Caustic and Corrosive Agents). Chloramine is less water-soluble and may produce more indolent or delayed irritation.
Chlorine gas. The recommended workplace limit (ACGIH TLV-TWA) for chlorine gas is 0.5 ppm (1.5 mg/m3) as an 8-hour time-weighted average. The short-term exposure limit (STEL) is 1 ppm. The level considered immediately dangerous to life or health (IDLH) is 10 ppm.
Aqueous solutions. Dilute aqueous hypochlorite solutions (3–5%) commonly found in homes rarely cause serious burns but are moderately irritating. However, more concentrated industrial cleaners (20% hypochlorite) are much more likely to cause serious corrosive injury.
Inhalation of chlorine gas. Symptoms are rapid in onset owing to the relatively high water solubility of chlorine. Immediate burning of the eyes, nose, and throat occurs, accompanied by coughing. Wheezing also may occur, especially in patients with preexisting bronchospastic disease. With serious exposure, upper airway swelling may rapidly cause airway obstruction, preceded by croupy cough, hoarseness, and stridor. With massive exposure, noncardiogenic pulmonary edema (chemical pneumonitis) may also occur.
Skin or eye contact with gas or concentrated solution. Serious corrosive burns may occur. Manifestations are similar to those of other acidic corrosive exposures (See Caustic and Corrosive Agents).
Ingestion of aqueous solutions. Immediate burning in the mouth and throat is common, but no further injury is expected after ingestion of 3–5% hypochlorite. With more concentrated solutions, serious esophageal and gastric burns may occur, and victims often have dysphagia, drooling, and severe throat, chest, and abdominal pain. Hematemesis and perforation of the esophagus or stomach may occur.
Diagnosis is based on a history of exposure and description of the typical irritating odor, accompanied by irritative or corrosive effects on the eyes, skin, or upper respiratory or GI tract.
Specific levels are not available.
Other useful laboratory studies include, with ingestion, CBC, electrolytes, and chest and abdominal radiographs; with inhalation, arterial blood gases or oximetry and chest radiography.
Emergency and supportive measures
Inhalation of chlorine gas
Immediately give humidified supplemental oxygen. Observe carefully for signs of progressive upper airway obstruction and intubate the trachea if necessary (See Airway and Breathing).
Use bronchodilators for wheezing and treat noncardiogenic pulmonary edema ...