Firewall sealant is a chemical substance used to close off connecting pieces of a barrier meant to prevent the spread of fire. The substance must be fireproof, and must conform to standards ensuring that the sealant will not allow flames to travel through these connective spaces.
Many silicone elastomer firewall sealants exist for use in buildings. These are made to be applied on walls, floors, ceilings and other parts of a building. Some of these sealants are flexible, meaning they can form a tight seal, even in areas that are often moved.
Many types of engines require firewalls and sealants for those firewalls. Airplanes particularly need to be as fireproof as possible, so special sealants are made for aviation. Many of these are made for high-vibration areas where the sealant might come off as a result of movement. They also are used in fuel cells that are connected to piping responsible for gas/air intake and exhaust.
