ICC (International Code Council)
ICS (Incident Command System)
ICU (Intensive Care Unit)
IDLH (Immediately Dangerous to Life and Health)
IFBA (International Fire Buffs Association)
IFSAC (International Fire Service Accreditation Congress)
IFSTA (International Fire Service Training Association)
IM (Intramuscular or Intermodal)
IMS (Incident Management System)
IMSA (International Municipal Signal Association)
IO (Intraosseous or Information Officer)
IR (InfraRed)
ISFSI (International Society of Fire Service Instructors)
ISO (Insurance Services Office or Incident Safety Officer)
IVP (Intravenous Push medication administration)
JFA (Joint Fire Academy)
JPR (Job Performance Requirements)
JVD (Jugular Vein Distension)
KSA (Knowledge, Skills, Abilities)
lac (Laceration)
LAFD (Los Angeles Fire Department)
LCES (Lookouts, Communications, Escape Routes, Safety Zones)
LACES (Lookouts, Awareness, Communications, Escape Routes, Safety Zones)
LDH (Large Diameter Hose)