Riot Control Agent Poisoning


Chloroacetophenone (CN), chlorobenzylidenemalononitrile (CS), chloropicrin (PS), bromobenzylcyanide (CA), dibenzoxazepine (CR), and combinations of these chemicals are irritant agents that belong to a class of agents collectively known as riot control agents or “tear gas”. Of the many tear gas agents used worldwide, CN and CS are the most common. Most exposures are inhalational, ocular, or dermal and typically lead to complaints of eye, nose, and throat irritation; hacking cough; suffocation or choking sensation; and dyspnea. High-dose exposures in an enclosed space which likely occurs only rarely, may lead to the development of airway edema, non-cardiogenic pulmonary edema, and possibly respiratory arrest.

The amount and route of the exposure to tear gas and the premorbid condition of the person exposed will contribute to the time of onset and the severity of illness. For example, given a similar route of exposure, clinical effects may vary from mild to severe, depending on the concentration of tear gas to which a person has been exposed.

The following is a more comprehensive list of signs and symptoms that may be encountered in a person exposed to tear gas. Symptoms are not listed in order of presentation or specificity. Also, partial presentations (an absence of some of the following signs/symptoms) do not necessarily imply less severe disease.

  1. Respiratory signs and symptoms
    • Chest tightness
    • Cough
    • Cyanosis
    • Dyspnea
    • Hoarseness
    • Hypoxemia
    • Non-cardiogenic pulmonary edema
    • Sensation of suffocation
    • Tachypnea
    • Wheezing or rales
  2. Skin and mucous membranes
    • Skin: redness, pain, blistering, and burns
    • Ocular: lacrimation, ocular irritation and redness, blurred vision, corneal burns
    • Nasal: rhinorrhea, burning, irritation, edema
    • Oropharynx: oral burns and irritation, sore throat, hoarseness, dysphagia, salivation

Note: The actual clinical manifestations of tear gas exposure may be more variable than the syndrome described above.

Differential diagnosis

  • Ammonia
  • Chlorine
  • Hydrogen chloride
  • Hydrogen sulfide
  • Nickel carbonyl
  • Phosgene
  • Sodium azide
  • Sulfuric acid
Page last reviewed: April 4, 2018