20 Feb 2024

Safe storage of lithium-Ion batteries

How to Safely Use and Store Lithium-Ion Batteries in the Workplace

In the article below fire safety experts from Socotec discuss how to safely use and store lithium-ion batteries to protect the safety of people and workplaces.

Many millions of lithium-ion batteries are in use or storage around the world. Lithium-ion batteries are in regular use to power the many devices and vehicles that we use as part of our modern daily lives.

Fortunately, fire related incidents involving these batteries are infrequent, but there are significant fire related hazards associated with these battery cells. The combination of flammable electrolyte and significant stored energy can lead to a fire or explosion due to a single failure.

What is the main safety concern with lithium-ion batteries?

Where a battery cell creates more heat than it can effectively dissipate, it can lead to a rapid uncontrolled release of heat energy, known as ‘thermal runaway’. This can result in a fire or explosion, and may occur as a result of manufacturing defects, mechanical damage, exposure to external heating or overcharging/over-discharging.

Thermal runaway can lead to the venting of a range of gases from the battery casings, such as hydrogen (extremely flammable), carbon monoxide (toxic, asphyxiant, and flammable), and hydrogen fluoride gas (acutely toxic and corrosive).

When a battery cell ruptures/vents due to thermal runaway, immediate ignition of the emitted gases may occur, especially if the battery has a high State of Charge (SOC). Alternatively, the gases may accumulate unignited, with the potential for a very rapid combustion (deflagration) or explosion when an external ignition source is encountered.

Overview of fire safety law and lithium-ion batteries

If lithium-ion batteries are handled, stored, charged or used in an unsafe way within a building, this can have a significant impact on the safety of people in or around the premises.

Fire safety legislation in the UK requires the responsible person to reduce the risk of fire and the risk of the spread of fire on the premises. The responsible person must also take such general fire precautions as will ensure the safety of their employees; and take such general fire precautions as may reasonably be required to ensure that the premises are safe.

The Regulatory Reform (Fire Safety) Order 2005 applies to virtually all premises in England and Wales including workplaces and the common parts of all multi-occupied residential buildings.

The Regulatory Reform (Fire Safety) Order 2005 (and similar legislation in Scotland) require the responsible person to make a suitable and sufficient assessment of the risks to which people are exposed to identify the general fire precautions they need to take.

Ensuring your building is lithium-ion battery safe and compliant

The extent of the use, handling, storage and charging of lithium-ion batteries will vary considerably from premises to premises. Fire safety management controls will also therefore need to be scaled appropriately for the level of hazard presented.

Undertaking a suitable and sufficient fire risk assessment in compliance with the Regulatory Reform (Fire Safety) Order 2005, is the first step to ensuring the level of fire safety management and provision of effective fire safety controls is appropriate for the building. From there, appropriate levels of controls can be determined to mitigate the level of risk encountered in the circumstances of the case.

How can I ensure that my lithium-ion battery arrangements are effective?

The use, storage, handling and charging of Lithium-ion batteries can increase the risk of fire within a premises, and therefore increase the risk of harm to people to whom there is a duty of care to protect.

Undertaking a suitable and sufficient fire risk assessment in compliance with the Regulatory Reform (Fire Safety) Order 2005, is the first step. The fire risk assessment should be undertaken by a suitably competent person and should cover handling, storage, use, and charging of lithium-ion batteries.

Does a fire risk assessment have to cover lithium-ion batteries?

A fire risk assessment is a careful look at your premises, the way in which they are used and the people who use them, from a fire safety perspective. It’s about understanding the potential risks, then making recommendations to ensure that your fire safety precautions are adequate to keep people safe.

For a fire risk assessment to be considered “suitable and sufficient” in accordance with the Regulatory Reform (Fire Safety) Order it must consider all significant risks of fire. This would include fire safety considerations in relation to lithium-ion batteries if they are being stored, handled, used or charged within the premises.

Best practices for ensuring lithium-ion battery safety 

The significant findings from the fire risk assessment should provide recommendations on how to ensure that Lithium-ion batteries are handled, used, stored or charged safely. Each contribute to a strategy for fire risk management and safety measures.

Typical recommendations may relate to:

  • Only using equipment that is supplied by reputable manufacturers or suppliers and only charging batteries with a suitable OEM (original equipment manufacturer) or compatible charger designed to safely charge the specific battery cells or battery packs in use.
  • Frequent inspections of batteries for signs of damage. (Never use damaged or defective batteries.)
  • Ensuring that battery handling areas are dry, cool, well-ventilated and free from high levels of humidity.
  • Ensuring that battery handling areas are free from flammable or combustible materials, sharp objects and that batteries are not left in contact with conductive materials.
  • Ensuring that battery charging is well managed by trained staff ensuring that batteries are removed from chargers after charging is complete, and that batteries are not left on charge in un-occupied locations.
  • Ensuring that staff are fully trained on the emergency procedures and the specific instructions for dealing with damaged or faulty batteries. Staff should be aware of their limitations in relation to dealing with fires involving Lithium-ion batteries.
  • Keeping batteries not in use in appropriate enclosures such as a proprietary metal battery storage cabinets or fireproof safety bags.
  • Provision and maintenance of a suitable smoke detection system which provides adequate warning to other occupants of the building (ideally combining smoke and carbon monoxide (CO) detection).
  • Limiting the size of storage areas, and ensuring they are dedicated to Lithium-ion battery storage only.
  • Consideration of externally sited, non-combustible containers or enclosures positioned no less than 3 metres from other buildings, equipment or risks.
  • Provision of 2-hour rated fire compartmentation where lithium-ion storage forms part of an internal storage arrangement.
  • Reducing the potential for thermal runaway by reducing the State of Charge (SOC).
  • Consideration for the provision of sprinklers to an appropriate sprinkler system design. (The packaging arrangements of lithium-ion batteries is considered to be a key element in the success or failure of a sprinkler protection system. Fire control may be achieved when sprinklers wet and cool cardboard packaging, such that chain thermal runaway reactions are prevented and fire spread contained.)
  • Consideration for the provision of a fixed extinguishing agent flooding system.

Why should you engage with a fire safety consultant for lithium-ion battery safety? 

Fully qualified and experienced fire safety consultants can undertake this fire risk assessment for you to ensure that it is suitable and sufficient in accordance with the duties imposed on the responsible person by the Regulatory Reform (Fire Safety) Order.

Our team of fire safety consultants will undertake a bespoke fire risk assessment of your premises. This will include an assessment of the likelihood of fire, the potential consequences for life safety in the event of a fire and an evaluation of the risk to life from fire in your premises.

Once the fire risk assessment has been completed, a thorough report is provided to identify all significant findings, faults or deficiencies and advise through a tailored action plan on how these can be mitigated to support you in ensuring you remain fully compliant and maintain protection of your workforce and/or residents.

Where Lithium-ion batteries are found to be used, stored or charged in the premises, appropriate recommendations will be made to support you in taking the most appropriate actions in relation to this risk.

 

Company info: Socotec