The UK’s continued drive towards a more sustainable society is seeing an increased reliance on batteries to fuel our industrial vehicles and machinery. However, this high risk electrical power source brings about an entirely new set of fire risks.
So how do you identify the new risks, address them effectively and safeguard your people and assets?
What does the legislation say?
Various regulations, including the Fire Safety Order (2005), apply to businesses storing batteries or other electrical equipment. These can provide a strong foundation for an effective risk mitigation strategy.
The Fire Safety Order (2005)
- Businesses must carry out regular risk assessments to identify any new or evolving safety risks.
- Findings should be used to drive the creation of or changes to a fire management strategy, which highlights the control measures necessary to minimise risk.
- For batteries and power electrics, the measures should guide processes, such as the design of battery storage areas and install of any large capacity charging points.
Depending on their nature, some facilities may also be subject to the Dangerous Substances and Explosive Atmospheres Regulation (2002), which requires an individual assessment to address specific risks.
Battery fire risks
- Thermal runaway and toxic emissions
Thermal runaway is the greatest risk of any battery fire. It is used to describe the chemical state in which a battery is rapidly rising in temperature, allowing excessive heat to generate more heat and propel the temperature further. This state is often a consequence of internal cell failures, overvoltage or mechanical defects of the battery.
If uncontrolled, thermal runaway can cause the battery to reach dangerously high temperatures, resulting in toxic gas build-up or even explosions. A battery in thermal runaway can also produce its own source of oxygen, self-sustaining the fire. If not managed quickly, thermal runaway is also able to spread between battery cells.
Toxic gasses are a common by-product of thermal runaway, and batteries in this state can release multiple harmful emissions, including carbon monoxide (CO).
- Difficulty to control
Due to their unique propagation process, battery fires can be very difficult to control and extinguish. For any electrical fire suppression system, the fundamental aim should be to prevent thermal runaway or, when this isn’t possible, delay the fire’s propagation to allow for safe evacuation.
Different batteries can react in different ways once ignited, so it’s important to understand the potential reactions and address each of these individually.
- Failure of control systems
If the Battery Management System (BMS) fails, the battery loses its ability to monitor its operating condition, including its temperature and cell voltages. This can cause overcharging, overheating and further malfunction.
- Sensitivity to transients and damage
Lithium-ion (safEV) batteries are highly sensitive to any kind of mechanical damage or electrical surges. These can cause the internal battery cells to short-circuit, leading to overheating, fire and potentially explosion. Due to their frequent close proximity in storage, if an individual battery malfunctions, it can quickly cascade to any surrounding batteries, creating a large scale fire.
Reducing the risks
When protecting your business against the fire risks associated with batteries, ensuring effective controls over three elements is crucial: storage, transportation and maintenance.
Storage
Batteries in storage, particularly when stored for long periods of time, pose significant fire risks. Depending on your individual site, risk mitigation processes may include:
- Separating batteries from critical business areas
Splitting up your storage and operation zones with fire resistant walls and doors will ensure that any fire is contained for a period of time, enabling teams to evacuate safely and allowing time to effectively control the fire before it spreads.
- Installing an on-site ventilation system
An effective ventilation system will help to filter any toxic fumes emitted by batteries should they ignite, minimising the safety risk to teams.
- Protecting cables and ducts
Sealing cabling, heating, ventilation and air conditioning ducts with fire dampers and fire resistant covers can help to minimise damage should a fire break out or an alarm be activated.
- Installing a fire detection and suppression system
Your site’s fire suppression solution should be tailored to your individual risks, identified in your fire risk assessment.
If you regularly store or use batteries on site, your system should account for this. Traditional fire suppression solutions will only go so far in protecting your site against battery fire.
Transportation
- Movement of batteries
When batteries are moved in or around your site, they are highly susceptible to mechanical damage. It’s essential their transportation is managed carefully as any damage can lead to malfunction and overheating.
- Electric vehicles
Where batteries are the primary power source for on-site transportation, additional measures need to be implemented to ensure safety. As the risks are so different, traditional suppression solutions are limited in how effective they can be to prevent fires for electric and hybrid electric vehicles.
Maintenance
- Regular BMS maintenance
The Battery Management System (responsible for monitoring a rechargeable battery) should be maintained frequently to highlight any issues which could lead to overheating, overcharging or malfunction.
Planning for electrical safety
Your fire management strategy should be supported with a clear plan. That plan should be shared with every team member, helping to ensure they understand the measures in place and their role in an emergency.
For more information or advice, speak to a member of our team.
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