Page 41 - JSOM Summer 2024

Conducted Electrical Weapon Fire Risk
in the Presence of Supplemental Oxygen

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Jeffrey D. Ho, MD *; Donald M. Dawes, MD ; Brian Driver, MD 3

ABSTRACT
Background: Conducted electrical weapons (CEWs) are non- In 2011, Ho et al. described the introduction and use of CEWs
lethal weapons used in tactical environments. Tactical EMS into a healthcare system security department and reported
(TEMS) operators provide patient care in environments where good ability to control situations that could result in further
CEWs are present. CEWs may produce a spark that can be a injury or violence. Since then, other healthcare systems have
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source of ignition. When supplemental oxygen is in use by a begun to use the CEW as part of their institutional safety and
TEMS operator, the flammability risk from the CEW is un- security plans. Because CEWs are a frequently carried tool by
known. Methods: We measured oxygen levels over 20 minutes law enforcement officers, it stands to reason that CEWs will be
in an enclosed space with a supplemental oxygen source max- present in most if not all environments where TEMS personnel
imally flowing. Measurements were taken at various distances provide care. Their presence elevates the risk of use. But ques-
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from the oxygen source to establish baseline concentrations. tions have arisen about CEWs and fire safety in the specialized
These concentrations were replicated within a plexiglass box environments of patient care because of the common use of
where a CEW was activated to create a sparking arc between supplemental oxygen.
probes embedded in a fresh swine shoulder (with skin intact).
Various flammable materials, typically found in a patient care CEWs operate by generating small pulses of electrical charge.
setting were used as potential fuel sources. Results: The high- These pulses are delivered at subtetanic rates to cause fused
est oxygen levels were achieved directly at the source. At 15cm skeletal muscle contractions and therefore incapacitation by
from the source, the maximum oxygen concentration was preventing voluntary movement. Many CEWs can “push” this
31.5%. Within the box, ignition was only achieved at oxygen charge over clothing or air gaps with sufficient voltage to cre-
concentrations greater than 45% and only when human hair ate electrical arcs. In addition, many CEWs have a “drive stun”
was present as fuel. No ignition was achieved at oxygen levels mode that involves two electrical contact points on the front
below this regardless of the tested fuel present. Conclusion: of the device pressed against skin to elicit pain compliance. A
Ignition from a CEW is possible at supplemental oxygen levels drive stun creates an arc to “push” the charge through the high
greater than 45% when human hair is present. In an enclosed resistance of the skin. These arcs pose some risk of ignition.
space, oxygen concentration levels of 45% are only present There have been cases of unintentional CEW-induced ignition
within 15cm of a flush rate oxygen source. The likelihood of when the devices are used under certain conditions, such as on
CEW-caused ignition in such settings with supplemental oxy- someone who has been in contact with flammable substances.
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gen in use is extremely low. Certain environments within the patient care setting may have
elevated risks for fire. In 2014, Kim et al. reported combustion
Keywords: conducted electrical weapon; TASER; oxygen; during a surgical procedure due to monopolar electrocautery
flammability; tactical EMS use. This type of incident leads to concerns about CEW arc-
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ing as a source of ignition in patient care settings.
While CEWs can purposefully generate an electrical arc to
Introduction
achieve a connection or complete a drive stun application,
Conducted electrical weapons (CEWs), often known as when both probes are deployed and embed well in tissue this
TASER devices (Axon Enterprises, Inc., Scottsdale, AZ), are arc may not be present. However, even if an arc is not present,
®
used in environments where violent encounters occur. Violent the electrical current is still flowing. With or without and elec-
events in traditional patient care settings are of significant trical arc, there is concern that use of a CEW provides a source
concern and have been well-described in the medical litera- of ignition. Since supplemental oxygen may be in use by TEMS
ture. 1–6 Tactical Emergency Medical Services (TEMS) provides providers and serves as a necessary component of ignition and
medical care in non-traditional, austere environments where combustion, there is a theoretical risk of the CEW providing a
violence is even more likely to occur. CEWs may be present source of ignition in an environment with enhanced flamma-
in both TEMS and more traditional patient care settings to bility. However, the true risk of this occurrence has not been
mitigate some of these violent events. established. This study examines the ignition risk presented by
*Correspondence to Jeffrey D. Ho, Department of Emergency Medicine, Hennepin Healthcare, 701 Park Ave. S., Minneapolis, MN 55415 or
jeffrey.ho@hcmed.org
1 Dr. Jeffrey D. Ho and Dr. Brian Driver are affiliated with the Department of Emergency Medicine, Hennepin Health System and the Department
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of Emergency Medicine, University of Minnesota Medical School, Minneapolis, MN. Dr. Donald M. Dawes is the site medical director at Exer
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Urgent Care, Camarillo, CA.
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