UMEM Educational Pearls

Category: Toxicology

Title: Riot Control Agents - submitted by Jake Danoff

Keywords: Riot control agent, Mace, pepper spray, tear gas (PubMed Search)

Posted: 6/4/2020 by Hong Kim, MD
Click here to contact Hong Kim, MD


Over the past several days, riot control agents have been used against the protest participants (related to Mr. George Floyd’s death). There are 3 widely used riot control “lacrimating” agents: 

  1. Mace (2-chloroacetophenone)
  2. Pepper spray (capsaicins)
  3. Tear gas (O-chlorobenzylidene malonitrile)

These agents (irritants) primarily affect the eye, skin, and respiratory tract.







·    Lacrimination

·    Blepharospasm

·    Conjunctiva irritation/conjunctivitis 

·    Periorbital edema

·    Corneal abrasions 

·     Copious H20/saline irrigation with Morgan Lensor Nasal Cannula jury-rig

·     Slit lamp exam for corneal abrasions 


·    Burning sensation

·    Blister

·    Contact dermatitis

·    2nd degree burns (mace) 

·     Wash with soap and water

·     Wound care 

Airway/respiratory tract

·    Respiratory tract irritation

·    Rhinorrhea

·    Laryngospasm

·    Bronchospasm

·    Chemical pneumonitis

·     B2-agonists for bronchospasm

·     Steroids if worsening underlying reactive airway disease 

·     CXR to evaluate for possible pneumonitis 

·     Supplementary oxygen as needed



  • Initial management involves copious irritation of the affected area with water. 
  • There is limited evidence that decontamination with milk, milk of magnesia, or baby shampoo is better than water. 
  • Always consider projectile or blunt trauma that may be associated with the riot-control-related ED visits/complaint. 
  • Protect yourself by wearing PPE when evaluating/treating these patients.


  1. Fisher, W. (2020). Retrieved 3 June 2020, from
  2. Schep, L., Slaughter, R., & McBride, D. (2013). Riot control agents: the tear gases CN, CS and OC—a medical review. Journal Of The Royal Army Medical Corps161(2), 94-99.
  3. Stopyra, J., Winslow III, J., Johnson III, J., Hill, K., & Bozeman, W. (2018). Baby Shampoo to Relieve the Discomfort of Tear Gas and Pepper Spray Exposure: A Randomized Controlled Trial. Western Journal Of Emergency Medicine19(2), 294-300.
  4. The Morgan Lens for emergency eye irrigation. Youtube. (2020). Retrieved 3 June 2020, from