Technical focus
Visible register staining alone does not establish that an entire duct system needs identical treatment; inspection should determine actual extent and deposition.
Coordinate HVAC operation during cleaning or drying so the system does not defeat containment or redistribute residues.
Use with the larger incident
This guide addresses one component of a fire and smoke loss. Fire & Smoke Intelligence connects it with heat damage, water migration, cleaning, drying and reconstruction sequencing.
Primary sources
Supporting technical references
These references support the general technical framework. Property-specific conditions, measurements and qualified inspection still control the actual scope.