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Horizons article 14 December 2023

Safe transport of lithium-ion batteries needs root and branch consideration

  • Maritime rules and safety
  • Industry Viewpoint
Issue 67

The uncertain risk in involved in moving lithium-ion batteries by sea, land or indeed by air is well documented. Many container ship fires have been caused or exacerbated by cargo containing lithium-ion batteries, including EVs. Clearly combatting this hazard is the responsibility of all involved in their transportation. TT Club’s Peregrine Storrs-Fox argues that there are fundamental issues that need to be resolved urgently.

Lithium batteries are today used to power a variety of products, including handheld devices (such as phones or cameras), through to larger items such as power tools and electric vehicles of all types. The market has expanded rapidly over the last two decades due to developments in electronics and now broader energy transition globally. Understanding the risks they may present during transport and storage is crucial. 

Following serious incidents, regulatory restrictions regarding the carriage of lithium batteries by air have been implemented, resulting in greater reliance on surface modes for movement around the globe. Coupled with a further number of recently recorded incidents, safety concerns around the transport and storage of lithium-ion batteries through the entire supply chain rightly continue to grow – particularly amongst the maritime community.   

The hazard that a given lithium-ion battery presents is primarily related to the amount of contained reactive substances, including lithium and other reactive material. The sharp rise in demand has been accompanied by supply of cheaper, poorer quality and untested batteries, including refurbished and even homemade power banks. E-commerce platforms have facilitated a global trade in these potentially lethal batteries, often circumventing global standards and regulations. 

Those in the logistics industry, covering both land and sea modes need to have a clear understanding of the dangers inherent in transporting these batteries which can include fire, explosions and toxic gas emissions.  The release of toxic fumes may be the first alert, but fire with temperatures higher than 1,000degs centigrade can be reached in a matter of seconds and, as the mix of chemicals and metals decomposes, devastation can ensue.  

Peregrine Storrs-Fox

Dangerous Goods Classification  

As with many successful technologies, market demand has outpaced the development of safety regulations. For many decades, lithium batteries have been classified under dangerous goods regulations for transport based on the weight of lithium contained in the cells or battery. As the technology has advanced, the amount of energy derived from the active material has increased by up to 50%, while the weight of cells has reduced greatly. This has been compounded by the way in which batteries are now combined in packs. At the point it was agreed that lithium batteries presented a different level of hazard to Lithium itself, the principle presentation was ‘button’ cells; what we see today is vastly different and the hazards are much closer to Class 4 ‘Flammable solids’. 

Given their nature and use, newly manufactured lithium-ion batteries can be transported by themselves as individual items, packaged with products (i.e. replaceable) or within products (not intended to be removed). In addition, consideration should be given to reverse logistics, including used, damaged and faulty products being returned, batteries being shipped as waste and those being shipped to be recycled. In all instances, the state of charge of any battery is a relevant factor; less stored energy generally equates to less risk. 

"It is now argued that there is a need for a radical review of the appropriate classification, as the size and energy capacity of these batteries has altered dramatically. Additionally, the volumes being carried in container ships and car carriers has mushroomed with the traded success of these energy storage components and devices."
Peregrine Storrs Fox

Peregrine Storrs-Fox

Risk Management Director, TT Club


Currently lithium-ion batteries are classified as one of four UN numbers, depending on power output or the weight of lithium in them and whether they are contained within devices or shipped separately. This diversity will shortly be expanded, but all these UN numbers continue to fall within Class 9  ‘Miscellaneous dangerous substances and articles’. Classification away from ‘Flammable solids’ was on the basis that the then smaller batteries presented reduced hazards compared to their larger counterparts through the supply chain.  

It is now argued that there is a need for a radical review of the appropriate classification, as the size and energy capacity of these batteries has altered dramatically.  Additionally, the volumes being carried in container ships and car carriers has mushroomed with the traded success of these energy storage components and devices. 

It is unsurprising to note that such reclassification is not an original idea. Over the last six years there have been ongoing debates touching on this at the relevant United Nations committee. From a layman’s perspective this – apart from the elapsed time – might offer hope. Not unreasonably, much of the conversation has been driven by research around the hazards presented and the types of reaction that may ensue. It is important to understand what may initiate decomposition, the temperatures that are critical, what energy and heat may be released, and suchlike.


Perhaps frustratingly, it currently appears that these tests are less focused on the inherent hazards and more on the reduction of State of Charge or packaging requirements to mitigate the hazards. Apart from worryingly inconsistent test results, little comfort is currently brought in relation to release of toxic gases, flammability or explosion risks – which are being experienced and are not ‘miscellaneous’ in nature. 

In addressing the commercial opportunities to move away from reliance on fossil fuels, there also needs to be urgent engagement from all involved in production and regulation of these batteries to resolve the justifiable concerns of the logistics industry. Perhaps it is time to recognise separately substances and articles that are prone to rapid decomposition and the expulsion of reactive energy. 

Iain Wilson: Surveying a future beyond LR