NSi Firestop814 fire stopping caulk is a single component, non-combustible, non-intumescent material for residential and commercial applications. Colored red for easy inspection, firestop814 creates an effective barrier against flames, smoke, and toxic gasses and has superior adhesion and gunnability. Firestop814 is for use in annular spaces around wires and pipes, in one and two-hour fire rated assemblies. It restores the integrity of firestops in residential and commercial construction. Meets UL 1479/ ASTM-E814 standards.