By Editor , 30 September 2026
ISO's New Class L Fire Rating Meets NYC's 1 kWh Battery Storage Rule

The Bronx, N.Y. – September 29, 2026 -- The International Organization for Standardization published the third revision of ISO 3941 on January 21, 2026, introducing Class L as a distinct fire classification for lithium-ion cell and battery fires, arriving as New York City enforces a 1 kWh threshold for lithium-ion energy storage systems under its amended NFPA 855 code.