Contained vs Controlled: What Is the Difference?

Wildfire field guide

Contained vs Controlled: what is the difference in wildfire reporting?

A wildfire can be contained before it is controlled. Containment is primarily about a completed control line expected to stop spread; control goes further by addressing nearby unburned fuels and hot spots that threaten that line.

Official definitions

Contained comes before controlled.

NWCG defines contained as a wildfire suppression status in which control line has been completed around the fire and associated spot fires and can reasonably be expected to stop spread. Controlled goes further: control line is completed, adjacent unburned fuels are dealt with, and hot spots threatening the line are cooled until the line can reasonably be expected to hold.

ContainedSpread is bounded.

The completed control line around the fire and spot fires is expected to stop further spread under foreseeable conditions.

ControlledThe line is further secured.

Threatening hot spots and adjacent fuels have been addressed so the control line can reasonably be expected to hold.

Why it matters

100% contained does not necessarily mean operations are finished.

Crews may still be mopping up, patrolling, detecting heat, repairing suppression damage or reducing resources after full containment is reported.

Containment is not extinction. Interior fuels can continue to smolder or smoke after the perimeter has been fully contained.

Read the report

Do not turn status words into a severity ranking.

  • A contained fire can still have smoke, heat and assigned resources.
  • A controlled fire has had additional work completed to reduce threats to the control line.
  • The terms describe suppression status, not total ecological or community impact.
  • Incident agencies may reduce public updates before every operational task is complete.
  • Always attach the status to its source and timestamp.

Sources

NWCG wildfire terminology.

Educational technical information. Suppression status should be interpreted with the incident’s latest official update and operational context.