FS-I fireproof sealant is a flame retardant, expandable sealant. Its characteristic is the good flame retardancy. When it burns, its volume will expand more than 3 times of its original volume (no constraint), and can effectively prevent flame and heat transferring. This kind of sealant mainly used in all types of cable and other fireproof and sealing parts and systems, such as vertical shaft, dish ark, cable penetration and metal penetration, etc.