Lithium-ion batteries – how to reduce the risk of fires in commercial buildings
Authored by Allianz
Lithium-ion batteries are the main type of rechargeable battery used and stored in commercial premises and residential buildings. The risks associated with these batteries can lead to a fire and/or an explosion with little or no warning.
Unfortunately, we’re seeing a significant increase in property fire claims caused by lithium-ion batteries, so we’ve collated advice to help prevent fires and keep properties and people safe.
Where are lithium-ion batteries found?
The easiest answer is everywhere. We all use lithium-ion batteries every day in mobile phones, laptops, power tools, e-cigarettes, e-bikes and e-scooters.
Residential buildings are likely to have tenants or occupiers using, storing and charging these batteries.
Warehouses and retail properties may have a stock of new or used lithium-ion batteries.
Products containing these batteries range from wearable technology devices (e.g. medical) to general plant and machinery (e.g. forklift trucks). Hand-held scanners for reading bar codes and picking goods often contain lithium-ion batteries. Automated storage and retrieval systems will have a large number of robots that may be powered by lithium-ion batteries.
Manufacturing premises often use portable hand tools, plant or machinery powered by these batteries. They may also manufacture, maintain or repair items with lithium-ion batteries.
Why do lithium-ion batteries catch fire?
If a battery cell creates more heat than it can effectively dissipate, it can lead to a rapid uncontrolled release of heat energy or thermal runaway, which can result in fire and/or an explosion. The most likely causes are from physical or chemical damage, heat, over-charging / over-discharging or defective manufacturing.
Thermal runaway can lead to the ejection of a range of gases. If a battery vents or ruptures due to a thermal runaway, immediate ignition of the emitted gases can occur. Alternatively the gases can spread, unignited, with the potential for a very rapid combustion or explosion. This can lead to a secondary fire and therefore spreading the original fire further.
The highest risk of a fire occurring is when a battery:
is being charged.is being transported, therefore at increased risk of damage.has been damaged previously, as thermal runaway can occur hours, days or weeks later.has been abused from over-charging or continual charging and discharging.
Reducing the risk of fire and explosion
General advice:
There are four basic styles of lithium-ion rechargeable batteries; cylindrical, button, prismatic and pouch cells. It’s accepted that cylindrical and button are inherently more robust and stable.A suitable and sufficient fire risk assessment should be undertaken and be subject to regular review. This should cover handling, storage, use and charging, where appropriate, with consideration also given to the requirements of the Dangerous Substances and Explosive Atmospheres Regulation (DSEAR) recognising the potential risk to people from energy-releasing events such as fires, explosions, thermal runaway etc.Emergency procedures, training, instruction and information should be provided, around handling and storage, especially of any damaged or suspected damaged batteries. It’s critical that training is delivered by a competent person(s) / organisation, is documented and that arrangements for refresher training are established.Clean-up operations following a fire need to be considered. Landlords of residential buildings should consider providing an external building, outside the main building for storage and charging of e-scooters and e-bikes. This could also be appropriate for other types of occupancies e.g. hotels.Batteries should be handled in well-ventilated areas and stored in dry and reasonably cool conditions i.e. avoid excessive humidity and heat.An automatic fire alarm should be installed or existing system extended to provide smoke detection in the area where batteries are stored or charged. Carbon monoxide detection could also be considered. Keep battery handling or charging areas free from flammable or combustible materials.Inspect all batteries for signs of damage upon arrival at the premises. This could include damage indicators to goods on pallets, visual inspections to packaging, or inspections of individual batteries.When bulk products or batteries are delivered, thermographic inspections can be used to indicate any otherwise invisible rise in temperature.Quarantine any batteries that have any signs of damage, have been returned and the condition is not known or have been within a faulty product. A damaged or defective battery must never be used.Reduce risk of physical damage to a battery, e.g. batteries that need to be charged should be handled individually and placed carefully into a charging cabinet. Do not place batteries near anything sharp that could puncture the cells.Depending on the chemistry involved, it’s also worth highlighting the relevance of the Control of Substances Hazardous to Health Regulations (COSHH) .
Battery charging
Only charge batteries with a suitable Original Equipment Manufacturer (OEM) or compatible charger.
Charging of batteries should be completed in a separate building, where possible 10m from main building and critical plant, or within a minimum 90 minutes fire rated enclosure. This could be an internal room, proprietary cabinet or bespoke container, depending on specific requirements. Batteries shouldn’t be left charging in unoccupied areas or premises.
Small size batteries e.g. those used in hand-held scanners, should be charged in a proprietary cabinet, internal to the building. These should have a minimum of 90 minutes fire rating. Depending on the nature of the risk and exposure, fire detection and suppression within the cabinet, maybe appropriate.
Charging of e-bike and e-scooters within residential buildings should be avoided. Where this can’t be avoided, they must not be charged in communal areas or on fire exit routes. Where batteries can be removed from e-bikes then this should be encouraged.
Battery quarantine
All lithium-ion batteries that are thought to be faulty, considered to be outside the manufacturers lifespan or showing signs of damage, should be quarantined. A suitable and sufficient enclosed container should be provided and kept at least 10 metres from the building. This could be something simple, e.g. a metal container with close fitting metal lid, filled with vermiculite granules.
Proprietary transport containers can be used, complying with the Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations (CDG), so they are ready for safe transporting. The regulations state that packaging should be leak-proof, with suitable inner and outer containers. The batteries should be encased in a proprietary non-combustible and electrically non-conductive thermal insulation material, e.g. vermiculite.
All quarantined batteries should be removed from the premises, on a regular basis, by a competent contractor and returned to the manufacturer for disposal.
Firefighting
Firefighting of a fire involving lithium-ion batteries must be left to the Fire and Rescue Service. Large lithium-ion storage areas will need special consideration around firefighting water run-off.
Consultation with the local Fire and Rescue Service should be undertaken, at an early stage of planning, for large storage areas, as well as enclosed and or basement areas.
Unlike lithium batteries, lithium-ion batteries do not contain lithium metal, which is highly combustible and reactive with water. Currently it’s accepted that water is the best medium to fight a lithium-ion battery fire, due to its effective cooling capabilities. Getting adequate quantities of water and directly to the battery can be a challenge. Specialist products have been developed which may be suitable for a small-scale battery fire or for life safety / escape purposes, e.g. specialist fire extinguishers, fire blankets or gloves.
Where sprinkler protection is installed the system could suppress a fire but it may not fully extinguish. It’s recognised that even a small lithium-ion battery fire could overwhelm sprinklers and therefore containment of a fire is key.
