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June 10, 2024


Lithium-Ion batteries. A guide to the fire risk that isn’t going away but can be managed

What role can extinguishers play in managing Lithium-ion battery fire risks?

There has been a steady rise in Lithium-ion battery fires in recent years as the number of devices containing them increases. Lithium-ion battery fires have unique attributes and are not like other types of fire, so it’s important be able to manage the fire event should the worst happen.  At Firechief® we are regularly asked about the role of fire extinguishers in managing and mitigating Lithium-ion battery fires.  Here we answer some of the most frequently asked questions.

Q:  Which extinguishing agents are effective on a lithium-ion battery fire?

A:  Conventional extinguishing agents vary in their ability to cope with a Lithium-ion battery fire. They’re not effective, but their different properties  mean that while some might have a level of suppression, they’re not going to be able to make the fire safe by reducing, slowing, or stopping thermal runaway.

Water:  Simply using a water extinguisher on a Lithium-ion battery fire will cool it but it won’t encapsulate it to form a thermal barrier around the cell in order to prevent it from propagating the reaction to the other battery cells.  Once the water extinguisher is empty, the thermal runaway reaction will start all over again. So, although  in effect, water will cool a lithium-ion battery, huge volumes of water will be required, and you will still need to put a barrier between the cells to stop the propagation between battery cells.

Foam: Foam extinguishers are even less effective than a water-based agent. As the foam doesn’t meet the high temperature requirements of the Lithium-ion battery fire, it simply isn’t effective.

Powder:  This is completely ineffective on a Lithium-ion battery fire as it has no cooling effect and won’t encapsulate the cells either.

Lith-Ex:  Firechief® Lith-Ex extinguishers are 83% water-based because water is the most effective method to cool.  The remaining 17% is AVD (Aqueous Vermiculite Dispersion) which  encapsulates to cut the cell off , thereby cutting the reaction down.  You need to cool, create a firebreak, and stop the reaction, so the quicker you do that, the quicker you make it safe. This is where both the water and the vermiculite part of the agent come together.

Q: Will submersion in water work for small devices such as laptops, phones, etc?

A: Submersion is only as good as suppression in this instance. Once you take the device out of the water the damage done to the battery will mean that once it dries out it could very easily go back into thermal runaway.

You’ve also got to remember that the toxins are now in the water that was used to submerge the device so you will need to consider how you get rid of that water.  Even with small devices, it’s still there, and has got to be disposed of safely.

Q: Why do you use vermiculite in Firechief® Lith-Ex extinguishers?

A: Vermiculite is a natural mineral with amazing thermal isolation properties. It’s used in many different products but the main reason we use it in Firechief® Lith-Ex fire extinguishers is the thermal insulation properties of the minerals.

Q: How does Aqueous Vermiculate Dispersion (AVD) work?

A: With Aqueous Vermiculite Dispersion the water provides quick cooling while the Vermiculite is suppressing and isolating the fuel source.   It then acts as a fire blocking barrier between the battery cells and provides a barrier over the top of the battery  cutting it off from the oxygen source and preventing it from propagating.  The vermiculite will then start to dry and forms a crust encapsulating the battery and device.

It has passed the 35-kilovolt dielectric testing and is safe from an electrical point of view.

Q: Can a Firechief® Lith-Ex extinguisher be used on other classes and types of fire?

A: Yes, it can.  From a Class A point of view, it is a very effective method of preventing propagation.    It is also very effective on Class D but will need a different type of nozzle.

Q: Are Lithium-ion batteries a Class D fire risk?

A: Lithium-ion battery fires are not a class D fire risk.  Being Lithium, they do get labelled as such, but because of the makeup of the cell, and there being no free metal in a Lithium-ion battery, it is not class D.  This type of fire has its own risks that are quite different to anything else.

Q: Are Firechief® Lith-ex extinguishers safe to use in the home, office, or a small space?

A: Absolutely.  Lithium-ion battery fires in devices such as mobiles and small tools can be effectively controlled using a Firechief® Lith-Ex extinguisher but remember not to put yourself or others at any unnecessary risk within the workplace.

Q: What training do people need to effectively use a Firechief® Lith-Ex extinguisher?

A: Training is really important, especially when you’re dealing with lithium-ion batteries as these are a new fire risk and they are very complex fires to tackle. It’s about education and understanding a lithium-ion battery and how and why they go into thermal runaway

You really should get anyone who’s trained within your organisation to deal with fires to understand the lithium batteries.  We’re not advocating people to become firefighters, but they should all have a good understanding of a lithium-ion battery fire and how complex these fires are.  This is why Firechief® offer CPD accredited courses for people to become more educated on this risk.

Q: What are the environmental impacts of using Firechief® Lith-Ex extinguishers?

A: Firechief® Lith-Ex extinguishers contain just water (83%) and vermiculite (17%) and will not cause any damage as vermiculite is an environmentally friendly product. It is a natural mineral mined from the ground.  Every single batch of vermiculite is batch tested to ensure that it’s pure.

Q: How likely is it that Firechief® Lith-Ex Extinguishers will become compliant with British Standards?

A: At the moment, there is no Lithium-ion battery fire standard, but the internal EN NTA 8133 Dutch standard is becoming the most globally recognized standard and is being adopted by BSI, as their test standard for Lithium-ion Battery fire.  We hope this will be adopted as quickly as possible and in the meantime are working with other standards agencies to certificate and verify our products as much as possible, so they already hold the Marine Directive, CA, UL Independent test, and BSI Kitemark for the A fire rating.  In effect, they hold as many standards as are available currently.

Q: What are the recommendations for servicing, refilling and extended maintenance of Firechief® Lith-Ex extinguishers in line with BS5306?

A: Firechief® Lith-Ex extinguishers can be serviced annually just like any other extinguisher under BS5306.  However, they cannot be refilled so we recommend that after 5 years they are taken out and replaced with new units, unless they’ve been used in which case they need to be replaced at that time just like any other extinguisher.


Additional resources:

E-Book ‘Lithium-ion Battery Fires – a guide to the risk that isn’t going away but can be managed’

Podcast – Lithium-ion Battery Fires – what you need to know

Firechief® Academy CPD accredited training courses



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