What a blanket does
DIN SPEC 91489, the specification EV fire blankets are certified to, defines one as a flexible blanket designed to limit the spread of fire in space and in time. Pulled over a burning car, it keeps the flames off the next car along, keeps radiant heat off the wall and the roof, and holds the smoke under the blanket.
What that buys you is time. Time to get people out, to move other vehicles if it is safe to, and for the fire crew to arrive at one burning car instead of three. Nottinghamshire Fire and Rescue Service has introduced EV blankets for vehicle incidents across the county and describes them as designed to help contain this type of fire.
Fire Cloak tested its blanket at HORIBA MIRA by pulling it over a Nissan Leaf in advanced thermal runaway, and reports that the temperature fell from over 900°C to 47°C in under ten minutes. That is a measure of containment. It does not tell you the pack has stopped reacting underneath.
What a blanket does not do
It does not put the fire out. Thermal runaway is a chemical reaction inside the cells that produces its own oxidiser, so cutting off the air does nothing to it, and the heat spreads cell to cell and restarts the process. A pack that looks out can reignite hours or days later.
Putting a battery fire out is the fire service's work, normally by cooling the pack with very large volumes of water over a long period. A blanket, an extinguisher and a hose on the workshop wall cannot do that.
So if any listing tells you a blanket smothers a battery fire or starves it of oxygen, read it as a containment product with the wrong description, and plan your fire procedure around containment.
There is also a live argument about using blankets on a fire that involves the battery. NFPA and UL FSRI research and an IAFF advisory (June 2025) warn of explosion risk from gas building up under the blanket. UK fire services have adopted blankets anyway. The answer for a site is training and a written procedure that says when the blanket goes on and who puts it there.
Call 999 first
London Fire Brigade's advice on lithium battery fires is to get out and call 999, and to never tackle one yourself. A blanket does not change the first step. Make the call, clear people away from the vehicle, and only then decide whether two trained people can get the blanket over the car without putting themselves at risk.
Your fire procedure should name who calls 999, who fetches the blanket and who puts it over the car. Decide that before the day, because nobody works it out well with a car alight in front of them.
If the car is already fully alight, or the people on site have not been trained on the blanket, the right action is to move everyone back and leave it to the fire service.
Where a blanket helps
A blanket earns its place anywhere a burning EV sits close to other vehicles or to a building you need to protect:
- Car parks. Cars parked side by side, often under a roof. Keeping a fire to one vehicle is the difference between one insurance claim and a row of them.
- Workshops and EV bays. Keep the blanket near the EV bay or the quarantine area, where two people can get to it quickly.
- Fleet depots and dealer forecourts. Vehicles parked tight, sometimes on charge, with a building behind them.
- Storage and salvage yards. Damaged EVs with compromised packs, where the risk is a car that catches fire hours or days after the impact. Quarantine comes first; the blanket is the backup if a quarantined car does go up.
- Recovery operators. The DfT guidance for recovery operators working with EVs lists a fire blanket in the kit a recovery vehicle should carry. Our recovery operator kit guide goes through that list.
Deploying one
Deployment is a two person job. The Fire Cloak 8 x 6m weighs 28kg in its bag, and two people pull it over the car by the reinforced handles. DIN SPEC 91489 tests for exactly that: a certified blanket has to be deployable over a vehicle by up to two people within 30 seconds.
Fire Cloak makes a 4 x 3m blanket for lithium battery fires, the 8 x 6m for saloons, hatchbacks, compact vans and smaller 4x4s, and a 12 x 9m XL for large panel vans, minibuses, people carriers and MPVs. Buy for the largest vehicle you regularly have on site, because a blanket too small for the vehicle cannot cover it.
Store it where it will be used, in its bag, with a clear route to the vehicles it covers. A wheeled storage box helps on a large site where the blanket may need to travel. Then rehearse with it. A blanket nobody has unfolded is a blanket nobody can deploy in 30 seconds.
Certification: what DIN SPEC 91489 tests
DIN SPEC 91489:2024-11 is the German specification for EV fire limitation blankets, and the Fire Cloak is certified to it. Fire Cloak's blankets were tested clause by clause by PZT GmbH, an accredited laboratory in Germany, and the results are specific to each model and size. Ask for the certificate for the exact blanket you are buying.
- Thermal resistance under direct and indirect flame, with no holes, no seam failure and no flame coming through for more than 5 seconds.
- Reaction to fire, classified under EN 13501-1. The Fire Cloak 8 x 6m is rated A2-s1, d0.
- Cut resistance, and the mechanical strength of the straps and the whole blanket under a 125kg diagonal load.
- Handling: it has to roll up and be deployable on a vehicle by up to two people within 30 seconds.
- PFAS-free materials, proper marking, manufacturer information and an IP65 storage bag.
A blanket that cannot show a certificate to a recognised standard is asking you to take its performance on trust. On a product you will only use in an emergency, the certificate is the evidence you have that it will hold.
Can you use it again?
It depends on what it was used for. Fire Cloak's guidance is that a blanket put over a car showing warning signs, such as a raised battery temperature or hissing and popping, that then did not catch fire can go back into service once it has been checked for mechanical damage and heat degradation.
A blanket that has been over a car that was alight is a different matter. It will be heavily contaminated with heavy metal and chemical residue, and any EV fire blanket in that state needs specialist decontamination before reuse, which is expensive. For most sites the practical answer is to treat it as spent and order a replacement the same day, so you are not left without one.
How this fits with our garage guide
This guide answers the question of whether blankets work. Our guide to EV fire blankets for garages covers the workshop side: why a traction battery fire is a different problem, how to quarantine a damaged EV, and how to choose and look after a blanket.
We sell the Fire Cloak EV fire limitation blanket, 8 x 6m, certified to DIN SPEC 91489 and made in the UK. The blanket and its wheeled storage box are in our EV fire safety collection.
Covering a car park, a fleet depot or several sites? Ask us for a quote with the quantity, the vehicle sizes and the delivery postcodes, and we will come back with a written price including delivery.