BOSS� 814 UL Classified Intumescent Latex Firestop Sealant is a one part, elastomeric, intumescent firestop sealant that expands when exposed to fire or extreme heat, forming an insulated char. BOSS� 814 will prevent the spread of toxic gases, smoke and fire. BOSS� 814 is suitable for adhesion to almost any surface and remains flexible, making it ideal for both horizontal and vertical joints, subject to vibration or dynamic movement. BOSS� 814 can be used for interior or exterior applications, and can be painted (after inspection). BOSS� 814 has been tested to ASTM E-814 (UL 1479) and meets the criteria for fire/smoke/draft stop for BOCA � CABO � UBC � SBCCI � IRC.