Last week we walked through thermal runaway — the self-feeding chain reaction that makes a lithium-ion fire so hard to stop. Knowing why these fires behave the way they do is one thing. Knowing what actually shuts them down is another. This week we set the talk aside and look at the numbers: what independent laboratories, fire brigades, and utilities have measured when they put F-500 EA against burning lithium-ion batteries.
Cooling That Goes Three Times Deeper
The NIOSH Pittsburgh Mining Research Division ran a study on two lithium-ion battery packs, comparing water mist with and without F-500 EA. On a 12-volt pack, water mist alone brought an average temperature of 250°C down to 75°C over 200 seconds. Add F-500 EA and the same 200 seconds took it to 25°C. Same water, same clock — three times the cooling. Because a lithium-ion fire reignites the moment cells sit above their thermal runaway threshold, that gap between 75° and 25° is the difference between a fire that’s out and one that’s just resting.
Stopping the Spread, Not Just the Flames
The real test of a lithium-ion agent isn’t knocking down visible flame — it’s stopping thermal runaway from jumping cell to cell. In 2024, FES Solution ran a full-scale EV burn at the Korea Fire Insurance Association’s testing institute using a Kia Ray EV with a fully charged 16 kWh battery: 16 modules, five cells each. A 3% F-500 EA solution knocked the fire down in under five minutes. When crews tore the pack apart afterward, only four of the sixteen modules had burned through. Propagation stopped.
A marine energy-storage test by KOSORI, built on UL 9540A principles, found the same pattern:
“F-500 EA® successfully suppressed fires at the initial stage, showing a significant and stable temperature reduction within 150 seconds and preventing thermal runaway from spreading to adjacent modules. No re-ignition was observed during the five-minute post-suppression observation period.” — KOSORI / KOMERI, 2024
The Toxic Gas Nobody Talks About
A burning lithium-ion battery doesn’t just throw heat — it releases hydrogen fluoride, a gas dangerous well below the levels most crews expect. Testing reviewed by Johnson Controls put hard numbers on what encapsulation does to that hazard:
“Testing shows, without extinguishment with F-500 EA, toxic HF gas levels released from burning lithium-ion batteries could reach 2,656 PPM. With F-500 EA, HF gas levels drop to 37.45 PPM and under, well below NIOSH’s 10 minute exposure limit of 95 PPM.” — Johnson Controls
NIOSH caps 10-minute HF exposure at 95 PPM. Untreated, these fires blow past that by nearly a factor of thirty. Faster knockdown means less gas, less runoff, and less exposure for everyone on scene.
Safe Around Live Electrical
Battery fires usually mean live voltage, and crews need to know the agent won’t carry current back up the hose. In 2017, Con Edison tested exactly that on a lithium-ion rack storage system. The finding: F-500 EA is safe to apply at both 3% and 6% from a 10-foot standoff on a 2 kV source — meeting the OSHA standoff standard for unqualified personnel on a 1 kV source.
Nearly Two Decades on Record
None of this is new. Bosch began comparative lithium-ion testing against water, foam, and dry powder back in 2008 and named F-500 EA its agent of choice a year later. The Port Authority of New York and New Jersey adopted it after 2022 testing on battery packs and a fully involved hybrid vehicle. That long track record is what earned formal recognition:
“NFPA 18A Annex 4.3 references over fifteen years of controlled, scientific, and highly instrumented lithium-ion battery fire testing documenting a history of successful fire suppression and fire containment.” — NFPA 18A
And because F-500 EA is fluorine-free, none of that performance comes at the cost of forever chemicals in your runoff — a distinction that matters more every year as fluorinated agents get phased out.
What the Numbers Say
The data points in one direction: deeper cooling, halted propagation, dramatically lower toxic gas, and safe application around live voltage — documented across independent labs and real-world adopters for the better part of twenty years. When a department is deciding what goes on the truck for the lithium-ion calls that are only getting more common, that record is worth knowing.
