Fire-caulking is required for any spaces that are required to maintain a certain rating such as between floor. This means around any space around any type of penetration. Large spaces are allowed to use Rocksul ( I think thats the spelling) which is basically a fiberglass insulation. Properly rated caulk as listed by UL as suitable for the purpose doesn't breakdown when it gets hot and stays pliable so expansion and contraction of penetrations do not create additional gaps.
The proper caulk around here is about 15 bucks a tube.
