Health and Safety Officer and Incident Safety Officer Definitions

NFPA 1521- 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- 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.