Conducted Electrical Weapon Fire Risk in the Presence of Supplemental Oxygen.

Background: Conducted electrical weapons (CEWs) are nonlethal weapons used in tactical environments. Tactical EMS (TEMS) operators provide patient care in environments where CEWs are present. CEWs may produce a spark that can be a source of ignition. When supplemental oxygen is in use by a TEMS operator, the flammability risk from the CEW is unknown.

Methods: We measured oxygen levels over 20 minutes in an enclosed space with a supplemental oxygen source maximally flowing. Measurements were taken at various distances from the oxygen source to establish baseline concentrations. These concentrations were replicated within a plexiglass box where a CEW was activated to create a sparking arc between probes embedded in a fresh swine shoulder (with skin intact). Various flammable materials, typically found in a patient care setting were used as potential fuel sources.

Results: The highest oxygen levels were achieved directly at the source. At 15cm from the source, the maximum oxygen concentration was 31.5%. Within the box, ignition was only achieved at oxygen concentrations greater than 45% and only when human hair was present as fuel. No ignition was achieved at oxygen levels below this regardless of the tested fuel present.

Conclusion: Ignition from a CEW is possible at supplemental oxygen levels greater than 45% when human hair is present. In an enclosed space, oxygen concentration levels of 45% are only present within 15cm of a flush rate oxygen source. The likelihood of CEW-caused ignition in such settings with supplemental oxygen in use is extremely low.