Irritant Gases Fact Sheet
Information for Healthcare Facilities
This quick reference provides information for healthcare professionals on exposure to irritant gases, including ammonia, chlorine, phosgene, and sulfur dioxide.
Last revised: August 2026
View or Download the Irritant Gases Fact Sheet (PDF)
Quick Information
Causative Agent:
Ammonia, chlorine, phosgene, sulfur dioxide
Hospital Precautions:
Standard Precautions. A positive-pressure, self-contained breathing apparatus (SCBA) or air-purifying full-face respirator (APR) is recommended in response situations.
Transmission:
Persons exposed only to gases pose no risk of secondary contamination to others. However, clothing or skin soaked with solutions containing these products may be corrosive to rescuers and may secondarily release harmful gas.
Decontamination
Remove and double-bag contaminated clothing and personal belongings. Flush symptomatic or contaminated exposed skin and hair with plain water for 3 to 5 minutes. Wash thoroughly with soap and water. Rinse eyes thoroughly for 20 minutes with copious amounts of water.
Mechanism
Irritant gases result in local tissue, corrosive effects, mucous membrane irritation, and respiratory tract irritation by reacting with water to form acids and free oxygen radicals.
Routes
Inhalation is the primary route; also dermal, ocular, mucosal membranes, ingestion.
Symptoms / Onset
Onset of symptoms varies based on the water solubility of the gas.
- Highly water soluble: Ammonia, sulfur dioxide, bromine show immediate irritation to upper respiratory tract and mucous membranes.
- Intermediately water soluble: Chlorine gas has immediate irritation with increased risk of pulmonary edema after several hours and requires additional observation time of 6-8 hours in symptomatic patients.
- Slightly water soluble: Phosgene may be asymptomatic or minor upper respiratory tract irritation. Delayed pulmonary edema >48 hours can occur in large exposures.
Symptoms include conjunctivitis, rhinitis, pharyngitis, lacrimation, burning sensation in the throat, mouth, nose, eyes, cough, shortness of breath, chest pain, nausea, vomiting, dizziness, and headache.
Symptoms can progress to upper airway edema, laryngospasm, severe pulmonary edema, pneumonia, persistent hypoxemia, and respiratory failure.
Exposure to liquefied phosgene or chlorine can result in frostbite injury.
Treatment
There is no antidote. Supportive care is mainstay of treatment.
Oxygen (humidified is preferred) therapy should be used in patients with dyspnea, wheezing, or pulse oximetry reading of SaO2 of less than 94%. Chest radiographs should be obtained in symptomatic patients with respiratory symptoms.
If bronchospasm and wheezing occur, consider bronchodilators (inhaled albuterol or other beta-agonists). Nebulized bicarbonate 3.75% can be used in severe cases for symptom relief.
Irrigate eyes with large volume of water or saline until ocular pH returns to normal.
There is no known prophylaxis for exposure to irritant gases.
Adapted with permission from the Kansas Poison Control.
Need help accessing these materials?
Some resources on this page are provided as PDF documents. If you need these materials in an alternative or accessible format, please call Poison Help at 1-800-222-1222 or contact us—we will provide assistance.