A viral clip of an EV igniting was what started my worries about safety in car parks I have been designing. Are we ready for fast growing fires? Since 2019 I've learned and studied a lot, I've relaxed on some aspects of it and was able to identify they areas where a lot more engineering considerations should be placed. In this episode I would like to take you inside the engineering choices that shape outcomes: ceiling height, smoke control, structural details, and how fast systems wake up when seconds matter. Instead of arguing EV versus ICE, we look at what the data shows across 148 vehicle fire tests and why there’s no single “true” car fire curve.

Think of a car as a set of compartments—the cabin, engine bay, trunk, wheels, and for EVs the battery pack—each with its own vents and barriers. That lens explains the wildly different heat release profiles you see in experiments and helps you separate worst-case lab setups from realistic design scenarios. We unpack why rapid battery-led growth is so challenging for low garages, how beams can trap and extend flames under the ceiling, and how wind can either help by stripping hot gases or hurt by pushing fire across bays.

From there, we focus on consequences and controls. For evacuation, the goal is to avoid early smoke cut-offs and protect crowded egress moments after events. For firefighting, the single most important factor is a clear entry path—no smoke between the crew and the fire—so water can be applied fast to stop spread, even if battery cooling remains lengthy. For structure, isolated car fires shouldn’t be catastrophic in robust frames, but long, multi-vehicle burns can threaten integrity without early control.

What works? Height buys time and reduces ceiling flame attachment. Smart smoke control drains energy from the layer and lowers radiation to neighboring cars. Thoughtful layouts keep chargers away from exits and closer to exhaust paths. And suppression systems may not “kill” a battery, but they cut plume temperatures, slash spread potential, and make the entire operation safer. We also surface key gaps: natural battery-initiated growth rates, context-specific risk acceptance, and handling potential explosive gas releases with low-level detection and dilution modes.

If you like to learn more, see more here:

Miechówka & Węgrzyński: Systematic Literature Review on Passenger Car Fire Experiments for Car Park Safety Design

Zahir & César Martín-Gómez: Evaluating Fire Severity in Electric Vehicles and Internal Combustion Engine Vehicles: A Statistical Approach to Heat Release Rates

• Collection of Fire Science Show episodes on cars and batteries
• Episode 6 - my early research on fast fire growth
• Episode 190 - Review of research on vehicle fires
• Podcast episode 135 - Contemplating a car park design fire

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

It is a massive effort to rewrite a national fire safety code around measurable risk, explicit targets, and cost-effectiveness. But sometimes, there are great reasons to do so. In this episode, together with Gianluca De Sanctis and Sofia Kourgiantaki we take you inside Switzerland’s sweeping reform, where a new federal law sets a maximum individual risk for life safety, ties property protection to a clear marginal cost rule, and harmonises practice across cantons. Together, we trace how the framework defines acceptance criteria, builds a shared “model code” of probabilistic inputs, and keeps prescriptive pathways for standard projects—only now grounded in risk-optimised measures.

You’ll hear how the system replaces vague equivalence with transparent math. Life safety is anchored at 5×10^-5 fatalities per user per year; if a building exceeds that threshold, measures are required until it doesn’t, regardless of cost. Beyond the threshold, optimisation is driven by the marginal cost principle and a nationally defined social willingness to pay, aligning fire with flood, transport, and earthquake risk policy. For property, the rule is simple and strict: do not spend more than the expected damage you remove.

While the code was being developed, Sofia put the method to the test in a retail centre case study using Bayesian networks and ASET/RSET. The model compared detection, sprinklers, and smoke exhaust while capturing occupancy, fuel loads, growth rates, system reliability, and fire service response. The surprising result: in a seven-meter hall, detection met the life-safety target on its own, and the most cost-effective optimisation paired detection with sprinklers, while smoke exhaust added little benefit in that geometry. The lesson isn’t that one system always wins; it’s that context and data should decide, not habit.

Switzerland didn’t stop at policy. A peer-review approval process, ETH’s advanced training in probability and risk, and a national model code make the approach usable and reviewable. The reform is in technical review ahead of political approval, with mechanisms for minor updates as evidence grows.

Direct links to the document:
- German Version: https://mitwirkung-vkf.ch/de/
- French Version: https://mitwirkung-vkf.ch/fr/

Also, there are 4 short videos in German, French and Italian that describes the new framework of the new codes:
https://www.bsvonline.ch/de/brandschutzvorschriften/projekt-bsv-2026/videos

A part of this shift in culture is also the new MAS in fire at the ETH, which you can learn more about in here:
https://mas-brandschutz.ethz.ch/

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

Demand for the energy storage is as high as ever, and is about to triple-quadruple. The development of technology is at unprecedented phase, and even within a single project you may face different cell, battery or container generations. This pace reshapes how we think about battery energy storage safety, from enclosure design to emergency response. We sat down with Noah Ryder from the Fire and Risk Alliance to unpack how BESS has evolved from walk-in containers to dense, modular “refrigerator” units—and how the move to liquid cooling, tighter layouts, and higher amp-hour cells impacts both opportunity and risk.

We explore the real jobs batteries do for the grid: shifting solar and wind, replacing peaker plants, stabilizing frequency, and powering microgrids. Then we zoom into the fast-growing edge case: AI-hungry data centers integrating batteries at the rack level for modularity and speed. That flexibility has a cost. Less free airspace and larger cells mean faster gas accumulation, higher heat flux into insulated enclosures, and a credible explosion hazard from a single failure. We walk through the failure timeline—monitoring anomalies, venting, immediate versus delayed ignition, sustained fire, and potential propagation—and identify practical interventions at each step.

Noah lays out the tradeoffs many teams avoid: accept that a damaged unit is a write-off, or try to save modules at all costs? Should we prefer a known flame over an uncertain blast by using intentional spark ignition? How should NFPA 855’s push toward gas-triggered mechanical ventilation and deflagration venting influence spacing, panel placement, and vent direction? We also dig into enclosure construction—non-combustible insulation, steel skins, coolant flammability—and how better insulation can safely cut spacing by slowing heat penetration and reducing internal temperature rise.

Looking forward, stacking feels inevitable. The smarter approach is to treat batteries not just as a cause but as a fuel, borrowing tested methods from high-rack storage: quantify heat release and radiant exposure, model gas evolution and overpressure, orient vents to manage flame jets, and define acceptable loss before design begins. If you care about real-world energy storage—utility sites, microgrids, or data centers—you’ll leave with a clearer framework to make informed, defensible choices.

If you would like to learn more about Noah and the Fire and Risk Alliance, you can find them online here: https://fireriskalliance.com/

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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.