Lithium power in construction: managing risk alongside innovation

Lithium battery power has changed the way we live our lives and whilst not a new innovation, over recent years, has been increasingly favoured on construction sites.

Batteries are used in a range of equipment and plant, such as power tools drills, dumpers, forklifts and excavators. Even solar generators rely on lithium powered battery energy storage systems (BESS).

It has even been suggested that lithium power may support more efficient, calmer work sites with reduced accident rates and afford more flexibility for works to be completed. The use of lithium-ion batteries is also an attractive prospect for contractors looking to reduce their carbon footprint and meet sustainability targets, but businesses all need to be alive to the additional risk lithium batteries can bring to site.

Lithium batteries may become volatile when under stress through:

• Overcharging
• Overheating through exposure to elements
• Impact damage / penetration
• Crushing
• Short circuit

This can lead to a chain of events in a battery cell called thermal runaway.

Potential impact on our customers

In the current climate, supply chain challenges are common, and delays lead to increased costs, potentially eroding the profitability of a project.

Current lithium battery guidance

Recognising the risk of Li-ion batteries, provisions have been included in The Joint Code of Practice on the protection from Fire on Construction Sites and Buildings Undergoing Renovation (JCoP).

A new section has been included covering the charging and storage of electric vehicles such as cars, vans, bike and scooters. This section emphasises the importance of charging points and storage areas being suitably distant from buildings under construction. The use of Electrical Energy Storage Systems (EESS) or Battery Energy Storage Systems (BESS) is also referenced as an alternative to generators.

This guidance can be found here.

What is Zurich currently seeing in the claims space?

An increase in fires claims through power tool stations being overcharged. Site offices pose a particular risk where over charged laptops have been known to overheat and ignite. In these cases, desktop paperwork becomes a combustible allowing fires to spread more easily.

As well as having to replace portacabin units, customers have experienced delays and financial loss through site access being impacted or from sub-contractors losing equipment and being unable to work at capacity. There is the potential for projects not being completed on time which could give rise to contractual penalties and reputational damage.

As construction firms embrace more sustainable building materials, such as harvested wood products and cross laminated timber, this can alter a risk profile. It’s important to ensure lithium battery fire risk is considered in fire assessments throughout the planning and build phases.

How to reduce lithium battery fire risk

Listed below are some practical steps which can be taken on site to reduce fire and injury risk and help support our customers’ projects complete on time and within budget. These steps can also help demonstrate a proactive approach to health and safety management.

• Incorporate lithium battery risks into Project Execution Plans or Project Management Plans as well as the site Fire Management Plan
• Introduce lithium battery hazard awareness training to all site staff. This should include regular visual inspection for the signs and symptoms of battery failure e.g. deformities
• Careful planning and consideration should be taken as to battery charging arrangements and the location of battery banks for power tools. Consider segregated areas for large plant and avoid storing alongside other fuel tanks or sources. Given the intensity and burn duration of electric vehicles, it important to also consider the risk of these being caught up in fires, as well as potentially causing them.
• Avoid overnight charging where possible. Where overnight charging is required, consider arrangements to prevent overcharging.
• Consult with your local fire and rescue service for guidance. Extinguishing lithium battery fires is challenging, and access, resources and equipment required to handle large scale occurrences may require planning.
• Provide suitable disposal routes for ‘spent’ batteries or single use items which may be brought on site, such as disposable vapes. These should not be put in normal waste disposal routes and factored into onsite smoking controls.
• Buy replacement battery packs from a reputable supplier to ensure these have undergone comprehensive testing and are compatible with UK power points
• Electrical vehicle charging units should be installed in accordance with manufacturers guidance and the IET Code of Practice for Electric Charging Equipment Installation. All installation, maintenance and servicing activities should be carried out by suitably certified contractors.
• Complete electric plant and charging point checks daily, particularly to high-risk areas such as forklift trucks and warehouses.
• Consider implementing ‘toolbox’ talks on site and training on the dangers of lithium batteries and how to dispose of defective ones safely. This will help raise awareness of the warning signs of power tool battery failure such as swelling, hissing, or an unusual smell.
• Create dedicated ‘cool off’ areas where overheating power tools may be placed and monitored

Fire detection and mitigation strategy

There are various options which can be considered, including automatic fire detection, gas and/or specific electrolyte vapour detection systems, deflagration venting and explosion protection provisions, audible and visual warning devices and compartmentation.

As lithium-ion battery fires are an accelerating risk, many innovative detection and fire protection technologies are often promoted. However, these solutions may not be suitable for their intended objective. To achieve the appropriate level of protection, each technology proposed for a given application should be thoroughly researched and evaluated by a competent person.

We are here to help

Please do get in touch if you would like to know more about how we can support you and your business.

This article was adapted from an article by Zurich which can be found here.