A ready to use foam designed to prevent the spread of smoke and toxic gases from one compartment to another, thereby slowing down the spread of fire. Can be used to seal around copper, PVC and wastewater pipes, as well as conduit and duct work. BOSS 812 Fire Block Foam prevents the spread of smoke and toxic gasses from one compartment to another, thereby slowing down the spread of fire, due to lack of air to fuel the flames. BOSS 812 has excellent insulation and acoustic properties and is also paintable (after inspection). BOSS 812 has been tested to ASTM E-84 and UL 723.