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DESCRIPTION
- Chlorine gas is a greenish-yellow, heavier-than-air gas with a pungent irritating odor.
- Under pressure or in combination with other chemicals, chlorine can exist as a liquid, a solid, or a gas.
FORMS AND USES
- Chlorine liquid is used to produce chlorine gas for use as an industrial disinfectant.
- Occupational exposures may occur during manufacturing of rubber and plastics, the bleaching of fabrics, the production of hydrochloric acid, and in the course of water and sewage purification.
- Other commonly used chemicals containing chlorine include household products such as bleach (e.g., Clorox) and other products containing sodium hypochlorite.
TOXIC DOSE
- Inhalation toxicity depends on concentration of gas and duration of exposure. Just one or two breaths of concentrated chlorine gas can produce serious injury.
- Ingestion of household bleach (5% sodium hypochlorite) is generally nontoxic; ingestion of more concentrated solutions may cause caustic injury.
PATHOPHYSIOLOGY
- Chlorine combines with water and liberates hypochlorous acid, hydrochloric acid, and oxygen free radicals, which are cytotoxic.
- Mixture of household bleach (hypochlorite) with ammonia-containing compounds may produce chloramine, a volatile irritant gas that produces effects similar to chlorine.
- Mixture of bleach with an acid may produce chlorine gas.
EPIDEMIOLOGY
- Poisoning is common and often occurs in the home.
- Toxic effects following inhalation exposure are typically mild to moderate, with death occurring in high-concentration exposures.
CAUSES
- Toxicity usually results from a household or occupational accident.
- Child neglect or abuse should be considered if the patient is less than 1 year of age, suicide attempt if the patient is over 6 years of age.
RISK FACTORS
Children may be more severely affected by chlorine gas because it is heavier than air and concentrates closer to the ground.
DRUG AND DISEASE INTERACTIONS
Patients with preexisting pulmonary disease are more susceptible to injury.
PREGNANCY AND LACTATION
High concentrations of hypochlorite are teratogenic in animal studies.
WORKPLACE STANDARDS
- Chlorine
- OSHA. PEL TWA is 0.5 ppm; PEL STEL is 1 ppm.
- NIOSH. IDLH is 25 ppm.
- Chlorine dioxide. OSHA. PEL TWA is 0.1 ppm (0.3 mg/m3).
- Chlorine trifluoride. ACGIH. TLV (ceiling limit) is 0.1 ppm (0.4 mg/m3).
- Odor detectable at concentrations of 0.5 ppm.
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DIFFERENTIAL DIAGNOSIS
Toxicologic causes of acute pulmonary injury include acrolein, ammonia, bromine, smoke inhalation, and phosgene, among others.
SIGNS AND SYMPTOMS
- Most serious exposures occur by inhalation and rapidly produce upper airway irritation and cough.
- Acute worsening may occur hours after inhalation exposure.
Vital Signs
- Tachycardia, tachypnea, and hypoxia are common following inhalation.
- Fever may develop if chemical pneumonitis and pulmonary edema occur.
HEENT
- Mucous membrane irritation (rhinorrhea and blepharospasm) is common.
- Upper airway obstruction may occur after high-concentration inhalation exposure.
- Conjunctivitis or corneal burns may occur from splash or high concentration exposure.
Dermatologic
Erythema and dermatitis are common following dermal exposure and related to concentration and duration of exposure.
Pulmonary
- Cough, chest pain, dyspnea, and bronchospasm are common following low-level exposures; wheezing, rhonchi, and rales also occur.
- Noncardiogenic pulmonary edema may occur following high-level inhalation exposure, but may be delayed for several hours.
- Reactive airway disease may develop after either severe acute or chronic inhalation exposure.
Gastrointestinal
- Nausea and vomiting are common following either ingestion or inhalation.
- Caustic gastrointestinal injury may follow ingestion of a large amount or a high-concentration solution.
Neurologic
- Headache and lightheadedness are common following low-level inhalation exposure.
- Syncope has occurred following high-level inhalation exposure.
PROCEDURES AND LABORATORY TESTS
Essential Tests
No specific tests are required following many mild exposures, especially ingestion of low-concentration solutions.
Recommended Tests
- Arterial blood gas and pulse oximetry should be monitored in symptomatic patients; hypoxia indicates severe injury or bronchospasm.
- Serum electrolytes, BUN, and creatinine should be assayed after serious inhalation or large-ingestion exposures; hyperchloremia or acidosis may occur.
- ECG, serum acetaminophen, and aspirin levels should be measured in an overdose setting to detect occult overdose.
- Chest radiography may reveal infiltrates in symptomatic patients, but normal chest radiographs obtained shortly after exposure do not preclude the development of delayed pulmonary effects.
- Pulmonary peak flows should be monitored to follow progress of bronchospasm.
- Bronchoscopy may be needed for severe pulmonary effects.
- Endoscopy should be considered for persistent gastrointestinal complaints following ingestion.
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- Supportive care with appropriate airway management is vital, with endotracheal intubation considered in serious exposures.
- Dose and time of exposure should be determined for all substances involved.
- Patients with dermal or ocular exposures should be checked for burns following irrigation procedures.
DIRECTING PATIENT COURSE
The health-care professional should call the poison control center when:
- Bronchospasm, airway obstruction, pulmonary edema, gastrointestinal, dermal injury, or other severe effects are present.
- Signs and symptoms are not consistent with chlorine poisoning.
- Coingestant, drug interaction, or underlying disease presents an unusual problem.
The patient should be referred to a health-care facility when:
- Attempted suicide or homicide is possible.
- Patient or caregiver seems unreliable.
- Symptoms more than a mild cough are present.
- Coingestant, drug interaction, or underlying disease presents an unusual problem.
Admission Considerations
Inpatient management is warranted if:
- Patient has experienced a high-concentration inhalation exposure.
- Patient exhibits upper airway edema, second- or third-degree burns, hypoxia, persistent respiratory symptoms, or caustic gastrointestinal injury.
DECONTAMINATION
Out of Hospital
- Inhalation. Patient should be removed from source of exposure.
- Ingestion. Emesis should not be induced.
- Dermal or ocular exposure. Affected area should be irrigated copiously with water.
In Hospital
- Ingestion
- Ipecac induced emesis is not recommended.
- Gastric contents should be aspirated gently with a nasogastric tube in patients presenting within 1 hour of a large ingestion; a large-bore orogastric tube is not recommended.
- Dermal. Affected area should be irrigated copiously with water or 0.9% saline.
- Ocular. Eyes should be irrigated copiously with 0.9% saline.
ANTIDOTES
There is no specific antidote for chlorine poisoning.
ADJUNCTIVE TREATMENT
Bronchospasm
- Oxygen should be administered, followed by albuterol 0.15 mg/kg (maximum of 10 mg) in saline with humidified oxygen via nebulizer every 20 to 30 minutes.
- If the peak expiratory flow rate (PEFR) is greater than 90% of predicted after initial dose, additional doses may not be needed.
- Patient should be monitored continually for response.
- Methylprednisolone and prednisone are used in the same manner as for asthma.
- Adult dose of methylprednisolone is 60 to 125 mg (1-1.5 mg/kg) given intravenously (pediatric, 1-2 mg/kg) every 6 to 8 hours.
- This may be decreased to a single daily dose and tapered.
- Prednisone, 2 mg/kg orally for several days, should be considered for cough or bronchospasm following inhalation exposure.
- Nebulized sodium bicarbonate has been recommended, but recent evidence indicates it is ineffective, and animal evidence suggests that it may cause a chemical pneumonitis.
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PATIENT MONITORING
- In an acute episode, continuous cardiac and respiratory monitoring should be performed.
- Long-term monitoring of pulmonary complications with pulmonary function tests is often needed.
EXPECTED COURSE AND PROGNOSIS
- Patients with low-level inhalation usually recover without sequelae.
- High-concentration or prolonged exposure may result in severe symptoms and permanent sequelae.
- Interstitial lung disease, pulmonary fibrosis, and reactive airway disease may occur following either severe acute or chronic inhalation exposure.
DISCHARGE CRITERIA/INSTRUCTIONS
- From the emergency department. A patient with hypochlorite solution ingestion or asymptomatic minor inhalation exposure may be discharged after symptoms have resolved.
- From the hospital. Patient may be discharged when respiratory symptoms and other effects are improving.
PATIENT EDUCATION
Patients should be instructed to return if they develop persistent coughing, difficulty in breathing, or chest pain.
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DIAGNOSISChest radiograph may be normal shortly after exposure and does not preclude subsequent pulmonary edema.
ICD-9-CM 983.9Toxic effects of corrosive aromatics, acids, and caustic alkalis.
See Also: SECTION IV, Caustics-Acidic chapter.
RECOMMENDED READING
Courteau JP, Cushman R, Bouchard F, et al. Survey of construction workers repeatedly exposed to chlorine over a three- to six-month period in a pulpmill. 1. Exposure and symptomatology. Occup Environ Med 1994;51:219-224.
Schonhofer B, Voshaar T, Kohler D. Long-term lung sequelae following accidental chlorine gas exposure. Respiration 1996;63:155-159.
Author: Edwin K. Kuffner
Reviewer: Katherine M. Hurlbut