Health & Safety Lithium-Ion Batteries

Health and Safety Review September 2025

Lithium-ion (LiB) batteries are a good example of how changes to the workplace need to be kept under review. Lithium-ion batteries are in use across a wide variety of areas/devices/products and in different sizes but the precautions needed are similar in each case.

Fires in lithium-ion batteries are extremely difficult to extinguish and are very energetic. The risk particularly occurs with damaged or faulty equipment or where batteries or charging equipment have been modified.

Ensure a separate risk assessment is carried out, including identifying hazards encountered in normal operation as well as including both planned and unplanned disposal of LiB items.

In summary:

• Include in fire risk assessment
• Pragmatically design a safe system of work for likely adverse events
• Communicate these safe systems of work
• Trial these safe systems of work, keeping them under regular review

Recommendations

• Ensure that a fire risk assessment of the building includes risk from lithium-ion batteries – including use, storage, charging, disposal
• Ensure that both risk assessments and safe systems of work for lithium-ion battery use, storage and disposal are in place
• Prohibit vehicles containing lithium-ion batteries from being left on, or adjacent to, escape routes
• Consider how to store devices containing lithium-ion batteries
• Consider how to charge devices containing lithium-ion batteries
• Communicate to all staff what the hazards are from lithium-ion batteries and what controls are in place and should be followed to keep them safe
• Review existing policies to ensure they address the challenges posed by lithium-ion batteries in the workplace. New policies may be required

Case Study

A company running care homes found:

• Mobility scooters parked in escape routes (including external)
• One mobility scooter storage unit adjacent to a fire escape
• Combustible items stored in mobility scooter stores
• Mobility scooters on charge overnight and without timers to turn them off when charged
• No fire or smoke detection in the mobility scooter store
• Six mobility scooters stored in close proximity to each other
• Mobility scooters being charged above a basement and below accommodation

What are the dangers?
Electrical Safety First commissioned BRE to perform a series of tests on lithium-ion batteries used in e-scooters and e-bikes. The tests demonstrated the explosive nature of these fires.

The tests on the batteries were performed by:

• Crushing them
• Overcharging them with an incorrectly specified charger
• Penetrating them with sharp objects such as could happen in a collision
• Placing the battery terminals next to each other to create a short circuit
• Dropping them from height
• Heating them up by placing them close to a heat source

During some of the tests the cells inside the batteries exploded, releasing toxic gases, flames, energetic sparks and enough smoke to rapidly fill a standard-sized hallway in a house.

In some cases, ignited cells were projected through-out the test area, with the potential to set fire to other materials. This happens because of ‘thermal runaway’ during which the heat from one cell ignites those next to it which in turn heat the next cells, and so on.