3M FIRESTOP Products are used and often required for sealing horizontal and vertical penetrations and joints in firewalls and fire separations. They prevent the spread of fire, smoke, fumes and drafts through walls, floors and ceilings in case of an actual fire. Other common uses include sealing around vents, pipes, ducts and other service or utility penetrations. An additional benefit is reduced noise and vibration transfer by creating an effective acoustical seal.