Health and Safety Officer and Incident Safety Officer Definitions
NFPA 1521-22.214.171.124 Health and Safety Officer (HSO). The member of the fire department assigned and authorized by the fire chief as the manager of the safety and health program.[1500, 2007]
NFPA 1521-126.96.36.199 Incident Safety Officer (ISO). A member of the command staff responsible for monitoring and assessing safety hazards or unsafe situations and for developing measures for ensuring personnel safety.