Health and Safety Officer and Incident Safety Officer Definitions
NFPA 1521-220.127.116.11 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 1521-18.104.22.168 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.