#United States #Lithium-Ion Battery #Bronx #Allstate Sprinkler #ISO Class L

New Fire Safety Standards in NYC

Recently, significant developments in fire safety concerning lithium-ion batteries have taken place in New York City. The International Organization for Standardization (ISO) has introduced a new classification specifically for lithium-ion battery fires—designated as Class L. This comes at a time when New York City is enforcing a stringent energy storage system (ESS) threshold set at 1 kWh, one of the lowest thresholds in the United States. These changes are crucial as the FDNY has been reporting an alarming increase in battery-related incidents.

Understanding Class L

On January 21, 2026, ISO released the third revision of ISO 3941, officially incorporating Class L into its fire classification system. The Class L designation pertains to fires involving lithium-ion cells that do not contain metallic lithium. This is a pivotal classification, distinguishing lithium-ion battery reactions—characterized by high energy density and the potential for rapid fire escalation—from other types of combustibles, such as those classified as Class D, which includes combustible metal fires.

The definition of Class L highlights numerous fire hazards unique to lithium-ion technology. These include:

• - Rapid fire growth: Lithium-ion batteries can escalate fire situations significantly faster than conventional combustibles.
• - Venting of hot gases: When a lithium-ion battery overheats, it can vent combustibles at high speed and temperature, creating additional fire risks.
• - Thermal runaway: This phenomenon can initiate a cycle of heating leading to fire spread and further combustion, thus complicating fire control efforts.
• - Re-ignition hazards: Even after extinguishing, the risk of re-ignition remains, especially if there is residual energy stored in the battery.

New York City’s Response

In line with the ISO’s revisions, New York City has tailored its building codes to reflect the unique risks posed by lithium-ion batteries. The city mandates stringent regulatory requirements for lithium-ion energy storage systems, where any installation above 1 kWh must undergo comprehensive review and approval. Comparatively, lead-acid batteries, a more traditional storage option, have a significantly higher threshold of 70 kWh before incurring similar regulatory scrutiny—illustrating the city’s proactive approach to lithium-ion risks.

FDNY Data Insights

A detailed analysis of incidents reported by the FDNY reveals a concerning trend. In 2024, the department documented 277 fires linked to lithium-ion batteries, a notable rise compared to 268 in 2023. Fortunately, the number of fatalities connected to these incidents significantly decreased. The data indicates that many lithium-ion fires transpired while the batteries were not charging—challenging the notion that charging alone is responsible for most hazards.

Learnings over the years have been pivotal in shaping regulations: about 60% of incidents occurred under non-charging conditions, emphasizing the need for comprehensive safety protocols regardless of battery charge states.

Implications for Building Owners

The arrival of ISO's Class L classification alongside New York City's revised regulations necessitates thoughtful reassessment of fire protection measures for buildings utilizing lithium-ion technology. Though this does not translate to an immediate overhaul of existing systems, it does require owners to acknowledge the distinct risks associated with lithium-ion batteries.

Sprinkler systems currently in place may not suffice without tailored solutions to address the unique fire characteristics of lithium-ion batteries. Building owners are encouraged to initiate formal assessments that include both FDNY and UL certification if they are storing or charging lithium-ion batteries.

Evolving Regulatory Landscape

In a comparable legislative move, New York State has also passed regulations effective from January 5, 2026, mandating warning labels in both English and Spanish for charging cords sold for micromobility and electric bikes. This is a preventative measure that aligns with NYC’s heightened awareness of electric device hazards, aiming to inform and mitigate risks proactively.

Conclusion

The introduction of Class L and the robust regulatory framework in New York serve to underscore the heightened awareness and need for meticulous safety measures surrounding lithium-ion batteries. The synergy between evolving international standards and local regulations reflects a community committed to safeguarding public safety in the face of advancing technological risks. Building owners must adapt to these changes, ensuring their infrastructure is equipped to handle the intricacies associated with lithium-ion storage and charging safely.