Pulmonary chemical agents


  • Ammonia, methyl isocyanate, methyl bromide, hydrochloric acid and chlorine, phosgene
  • Common toxic industrial chemicals, transported widely across country
  • Can affect central or peripheral airways
    • burning and irritation to epithelial lining causing airway edema or pulmonary edema, hypoxia, and hypotension


  • Choking agents combine with water in respiratory tract to form acids
  • Both chlorine and phosgene react with water in respiratory tract to form hydrochloric acid

Clinical Features

Symptoms dependent on the water solubility of the chemical

  • Highly water-soluble
    • Anhydrous, ammonia, Hydrogen chloride, Sulfur dioxide, Formaldehyde
    • Rapidly react with water causing damage to upper airway to vocal cords
    • Direct tissue damage causing edema/airway obstruction and laryngospasm
  • Moderately water-soluble
    • Damage to moderate-sized airways (bronchioles)
    • Bronchospasm and wheezing
  • Poorly water-soluble
    • Phosgene, Nitrogen dioxide
    • Inhaled deeply into alveoli
    • Lack of irritation of mucous membranes can cause them to go undetected

Differential Diagnosis

Chemical weapons



  • Liquid phosgene can cause off-gassing with release of toxin from clothes post-exposure
  • Do not allow patient to be active as it worsens condition
  • Diuretics and corticosteroids not shown to be effective
  • Inhaled beta agonists for bronchoconstriction


See Also

External Links