This is the 1123rd most frequent Polish word.
pożaru
"Pożaru" means "of the fire" or "of a fire" in English.
Here, "pożaru" is in the genitive case and refers to the origin of the blaze.
Straż pożarna szybko ugasiła ogień pożaru.
The fire brigade quickly extinguished the blaze of the fire.
In this case, "pożaru" indicates the source of the smell in the genitive case.
Zapach pożaru roznosił się po okolicy.
The smell of the fire spread around the area.
Here, "pożaru" is used to express a hypothetical situation of fire, again in the genitive case after "ryzyko."