Biostop® 66495 Bio Firestop Putty

One-part intumescent firestop product that can be hand pressed into place forming an immediate fire-seal.When exposed to fire, FSP expands to seal off voids caused by deteriorating cable jackets or plastic pipe and conduit, thereby maintaining the seal. FSP is similar in consistency to glazing putty. It does not set up, and the same material can be reused when adding or changing penetrating items. FSP pads are designed and tested for use around electrical boxes to seal off knockouts and prevent heat transmission under fire conditions.1" x 3" x 12" Putty Bar