Secondary contamination of emergency department personnel from o-chlorobenzylidene malononitrile exposure, 2002

Ann Emerg Med. 2005 Jun;45(6):655-8. doi: 10.1016/j.annemergmed.2005.01.031.


In a hazardous materials event in 2002, the unannounced presentation of 3 symptomatic, contaminated patients to an emergency department (ED) resulted in secondary contamination of 2 ED personnel who experienced skin, eye, and respiratory irritation. The material that caused these injuries was o-chlorobenzylidene malononitrile, a white powder with a peppery odor used largely as a tear gas and riot-control agent. Secondary contamination can cause adverse symptoms and injuries in ED personnel, further contaminate the ED, and potentially lead to costly ED closures and evacuations. To prevent secondary exposure, EDs can educate their staff about the potential for secondary contamination, implement a team approach for handling contaminated patients, establish decontamination protocols, ensure proper selection of and training in the use of personal protective equipment, and simulate drills for receiving contaminated patients.

MeSH terms

  • Allied Health Personnel*
  • Decontamination / methods*
  • Emergency Medical Services / methods*
  • Female
  • Hazardous Substances / toxicity*
  • Humans
  • Male
  • Occupational Diseases / chemically induced*
  • Occupational Exposure / prevention & control*
  • Terrorism*
  • United States
  • Workforce
  • o-Chlorobenzylidenemalonitrile / toxicity*


  • Hazardous Substances
  • o-Chlorobenzylidenemalonitrile