Canadian Underwriter

Large-format lithium-ion batteries greater hazard in warehouse fires than smaller such batteries: FM Global

December 7, 2016   by Canadian Underwriter

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Large-format lithium-ion batteries, such as those used in electric cars, tend to ignite more quickly in a warehouse fire and generally present a higher hazard than small-format batteries used in smartphones and laptops, according to new research.

One key finding was that properly configured ceiling sprinklers can suppress a fire, whether ignited by an exploding battery or an external source. Credit: FM Global.

FM Global, one of the world’s largest commercial property insurers, released the results of its newly conducted research on Tuesday. The research was used to refine fire protection guidance for lithium-ion batteries stored in warehouses, where sometimes there are hundreds of thousands of such items stored.

The research – Lithium Ion Batteries Hazard Use and Assessment – Phase III: Sprinkler Protection Criteria for Lithium Ion Batteries Stored in Cartons – included large-scale fire tests at the FM Global research campus in West Glocester, R.I., which FM Global reports is home of the largest fire technology lab in the world at 108,000 square feet and six storeys high.

Among the key findings was that corrugated board cartons and plastic dividers tend to catch fire before “significant involvement” of the batteries in cartons. “While the corrugated board cartons were shown to dominate the initial fire growth, the plastic content within the cartons was shown to be a driving factor in the overall commodity hazard,” the report said.

Another key finding was that properly configured ceiling sprinklers can suppress the fire, whether ignited by an exploding battery or an external source. “The sprinkler system used in the large-scale fire test was sufficient to protect against a fire where the Li-ion batteries were contributing more to the overall fire severity than occurred in the large-scale test,” the report noted.

“Executives, risk managers, fire protection organizations, municipalities and insurers all need definitive, empirically conclusive information on how to cost-effectively manage this increasingly prevalent storage risk,” said Louis A. Gritzo, vice president, manager of research at FM Global, in a press release. “Now we have it.”

FM Global reported in the research that “these tests showed that bulk storage of small-format (2.6 Ah) Li-ion batteries exhibit similar fire growth, leading to first sprinkler operation as other more common cartoned commodities. Further, it was determined that the time required for involvement of the Li-ion batteries in a fully developed fire is approximately five minutes. These conclusions provided the basis for sprinkler protection recommendations for small-format Li-ion batteries in bulk storage, with the goal of suppressing the fire before the anticipated time of involvement of Li-ion batteries.”

The tests build on FM Global’s Phase II research reported in May 2013 which, like this latest phase, was conducted in partnership with the non-profit Property Insurance Research Group and in collaboration with the National Fire Protection Association’s Fire Protection Research Foundation. Phase II research attempted to characterize the flammability of Li-ion batteries to provide the basis for fire protection guidelines of common small-format battery types in rack storage configurations. Phase I, conducted in 2011, consisted of a hazard and use assessment of Li-ion batteries, with a focus on warehouse storage.