NFPA 855 is a U.S. safety standard developed by the National Fire Protection Association that governs the installation of stationary energy storage systems, including lithium-ion battery energy storage systems (BESS). It outlines key requirements related to fire suppression, thermal runaway mitigation, separation distances, ventilation, and emergency response planning. NFPA 855 often works in conjunction with other related standards—such as UL 9540 and UL 9540A—which address system safety and fire testing methodologies. Together, these standards are critical for permitting, code compliance, and the safe deployment of energy storage systems.