FM Global Updates Its Lithium-Ion Battery Safety Recommendations

FM Global is a mutual insurance company whose capital, scientific research capability and engineering expertise are solely dedicated to property risk management and the resilience of its policyholder-owners. The company maintains their Property Loss Prevention Data Sheets to reduce risk at existing facilities or those under construction through its expert engineering recommendations. These best demonstrated practices help reduce the chance of property loss due to fire, weather conditions, and failure of electrical or mechanical equipment. They incorporate nearly 200 years of property loss experience, research and engineering results, as well as input from consensus standards committees, equipment manufacturers and others.

FM Global recently updated its Property Loss Prevention Datasheet 5-33 which provides guidance on the design, installation, and maintenance of lithium-ion battery systems. The datasheet covers various aspects of fire protection, electrical safety, and thermal management for these systems.

One of the important sections in the datasheet is on Early Intervention and Thermal Runaway Prevention. This section explains how to prevent or mitigate the occurrence of thermal runaway, which is a self-sustaining and uncontrollable increase in temperature and pressure in a battery cell that can lead to fire or explosion. The section recommends the use of an early interventions system to automatically and electrically isolate the batteries using temperature or an off-gas detection system capable of detecting volatile organic vapors (i.e., battery electrolyte solvent vapors) which precedes thermal runaway. This new recommendation to use an electrolyte solvent vapor detector to electrically isolate the batteries builds upon Section of NFPA 855 and demonstrates the trend to emphasize early detection in lithium-ion battery system.

Another important section in the datasheet is on Early Intervention Devices – Off-gas Detectors. This section describes how to detect and respond to the release of volatile organic compounds (VOCs) from a battery cell which occurs at an early stage of cell failure, before thermal runaway. The section suggests installing off-gas detectors near the battery modules or racks and interlocking them with the BMS to electrically isolate the lithium-ion battery energy storage system if an unsafe condition is detected. This method of early intervention has been successfully demonstrated to prevent thermal runaway caused by certain failure modes.

Li-ion Tamer is an industry leading provider of off-gas detection systems. Please contact us if you would like to learn more.

You can view and download the FM Global Property Loss Prevention Datasheet 5-33 on the FM Global website at