ISO's New Class L Fire Rating Meets NYC's 1 kWh Battery Storage Rule
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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. Allstate Sprinkler, a Bronx-based fire protection contractor operating since 1972, released an analysis linking the new global standard to New York's existing regulatory posture and to FDNY incident data spanning 2023 through mid-2026.