July 9, 2026 · 5 min read
Where the fire starts
A kitchen fire usually starts on the cooktop — but a recoverable cooktop fire becomes a building fire when flames travel up into a grease-coated exhaust duct.
What's in the duct
Volatile cooking oils condense on the cool interior of the duct, layer after layer, until the duct interior is coated in flammable residue that ignites from a small flare-up below.
What cleaning prevents
Cleaning the hood, plenum, and duct interior on a regular schedule removes the fuel. Without that residue, a cooktop fire stays a cooktop fire.
