Lithium batteries are becoming increasingly prevalent in industrial use. Compared to older battery technology, the advantages are clear: easier to maintain, faster charging and lighter in weight. There’s just one significant downside: they are a considerably higher fire risk compared to lead or nickel batteries. You might have seen images of laptop batteries exploding and destroying houses, or of recycling facilities having large fires due to storage of lithium batteries.
There are also significant health issues should a battery fire start. A large quantity of lithium batteries contain Fluorine, which combines with Hydrogen to produce Hydrogen Fluoride (HF) gas. This is a significant risk to health as it is highly corrosive and can easily be inhaled. Further, the battery will also produce hydrofluoric acid. Should a person come into contact with this, the acid will burn painlessly through the skin and tissue until it starts to eat away the calcium in the bone.
Management of the risk of Lithium batteries essentially boils down to three elements:
- Detection and Monitoring Pre-fire conditions can usually be detected by gas and vapour monitoring, and monitoring of abnormal temperatures. If you’re storing a large number of batteries, having early warning of an issue could limit damage and downtime.
- Suppression and Extinguishing Tests by the American insurer, FM-Global, and the German Insurance Association (GDV) have shown that sprinkler systems can assist in the management of fire conditions with lithium batteries. You should also consider onsite extinguishing methods. Specific extinguishers for this use are now available which can cool the battery and help prevent the fire from spreading.
- Separation It’s likely that fire suppression and extinguishing media, whilst good at minimising damage and losses, will not completely prevent a fire from starting. Keeping batteries away from sources of fuel is therefore essential to prevent subsequent damage. This could be as simple as storing batteries in a designated area and introducing housekeeping controls to keep combustible materials separate. There are, however, fire resistant cabinets and walk-in solutions that can be purchased for the safe storage of batteries.
Whilst thorough controls might take time to plan and implement, there are some simple short term controls that can be introduced immediately:
- Avoid deep discharge or overcharging. Depleting the battery completely, or charging for long periods, can damage the battery. Ensure that the charge current is below the maximum capacity of the battery pack.
- Inspect batteries regularly. It is common for batteries which are damaged to ‘vent’ gas. In sealed batteries, this is usually seen as the battery bulging or swelling. Any batteries displaying bulging or swelling should be removed and must not be used. Inspection of batteries should also be made after battery charging is complete as chemical reactions can still occur after the charge current is disconnected.
- Create a dedicated charging area. Keep combustibles away from this area.
- Store batteries with at least one terminal covered. This will prevent short circuits occurring, particularly if you are storing the battery on metal shelving.
- Have suitable extinguishers nearby.
- Have emergency first aid supplies, including neutralisers for hydrofluoric acid, near to areas where batteries are stored or used.
- Keep batteries away from extreme heat (above 50°C) or cold (below -10°C).
- If you are storing batteries for long periods of time, discharge them to 50-60% capacity.
The UK Government is concerned enough about the dangers posed by lithium batteries to have a draft bill at the second reading stage. The Lithium-ion Battery Storage (Fire Safety and Environmental Permits) Bill will have a second reading on the 24th March 2023. This bill is aimed entirely at the storage of lithium batteries and so it is wise to start considering the risks within your business now.
If you have any questions, please contact ProAktive where our consultants will be happy to discuss your exact circumstances.
By Ian Clayton CMIOSH – Managing Director, ProAktive Risk Management