Fire Door Caulk is the only tested and approved filler material for filling voids and through penetrations in existing listed and labeled wood fire doors. Using other types of filler material can void your UL listed assembly. Fire Door Caulk has been tested to the following criteria, NFPA 252, UL10C and CAN S104. The caulk has been tested for use in holes up to 3/4″ in wood fire doors rated up to 90 minutes.
NFPA 80 Compliant
Safety Data Sheet