SINGAPORE — As if shippers needed even more risk associated with their containerized supply chains beyond pandemics, droughts and attacks on vessels, yet another can be added to the list: fires on ships started by lithium-ion batteries.

Historically speaking, lithium-ion batteries have very quickly become ubiquitous in society and onboard ships, whether as cargo, in crews' personal devices or as part of the ship's equipment. Yet the shipping industry, while acknowledging the batteries are here to stay and can't be banned as cargo, is lagging behind in coming to terms with risks that remain poorly understood.

That is leaving crews, cargoes and ships exposed to the potential for extremely hot fires that occur without warning due to a chemical reaction inside the batteries known as "thermal runaway." Such fires, when started inside containers, are typically difficult to access and extinguish in part because traditional firefighting methods are ineffective.

And the risk is growing. The number of reported container ship fires soared in 2022 to 65, up from 31 in both 2021 and 2020, according to the Cargo Incident Notification System (CINS), a group of 14 container lines formed in 2011 to share data on cargo-related incidents. Lithium-ion batteries are the largest source of fires aboard container ships, the group said.

"The science of batteries themselves isn't particularly well understood, and how those batteries, if they do experience thermal runaway, behave on a ship isn't well understood, and how the equipment aboard the ship can be used to control the fires caused by lithium-ion batteries isn't particularly well understood," said Colin Gillespie, global head of loss prevention at NorthStandard Limited, a protection and indemnity (P&I) club. "So there are lots of things that aren't particularly well understood, and that makes insurers nervous and it makes people working in safety in shipping nervous."

Thermal runaway within a handheld radio's lithium-ion battery led to a 2022 bridge fire on an oil tanker docked in Baton Rouge, La., resulting in $3 million in damage to the vessel, the US National Transportation Safety Board (NTSB) said in November. More recently, a ship carrying lithium-ion batteries was ordered to anchor off Alaska in late December due to a fire onboard.

Safety as a shared responsibility

The reality of an industry ill-prepared for large quantities of lithium-ion batteries being shipped in containers, but actively trying to play catch up, was made clear in a December seminar in Singapore titled "Lithium-ion Batteries in the Logistics Supply Chain" organized by CINS, TT Club and the International Group of P&I Clubs.

Addressing the risk is partly in the control of container lines that can improve their ability to respond to fires once they have started, while using new approaches to methods, training and equipment. But it's also partly out of their hands, as it's impossible to know when lithium-ion batteries will ignite because defects that trigger thermal runaway are hidden inside the battery itself.

At a more basic level, carriers don't always know when the batteries are even present onboard a ship or within specific containers given that, similar to other dangerous cargo, they are not always properly declared. That is why speakers at the forum insisted that improving safety is a shared responsibility among all parties in the supply chain, including customers.

Even when cargo is properly declared, container ships regularly get loaded with a range of dangerous cargoes. A risk management executive for a large carrier summed up the challenge by recalling outreach from a stowage planner seeking advice on how to load a 23,000-TEU ship with more than 80 FEUs of fireworks, 30 FEUs of charcoal and 200 FEUs of electric vehicles shipped in containers.

"All shipping lines are facing a huge demand for electric vehicles to be transported by containers," the executive said.

'A change of risk profile'

Thermal runaway is known to be triggered by any number of factors — damage to the battery, overcharging, heat or contamination. "A lithium-ion battery cell can spontaneously experience a thermal runaway if damaged, shorted, overheated, defective or overcharged," NTSB said.

"We know how to control fires, but what we can't do is stop the thermal runaway, and that means the fire might come back, or that a vapor cloud might keep being produced," NorthStandard's Gillespie said. In other words, "I put the fire out, but it's not really out, so what do I do next? Lithium-ion battery fires are hard to extinguish because of the chemical nature of the fire and the fact that it's self-sustaining."

Gillespie described an aggressive effort under way by the industry to respond.

"The container and vehicle carrier operators are really thinking about how they can use existing control measures to try to put out fires that may arise from lithium-ion batteries," he said. "Additionally, all sorts of technologies are being explored. Technologies that let you find out about thermal runaway sooner, that help you control the fire better. There is quite a lot of research going on in various parts of the world around this.

"The frequency of fires and explosions due to lithium batteries is considered to be low," Gillespie added. "The number of fires compared to the number of batteries shipped is very low, but when it does happen it's a problem. There is a change of risk profile, and we don't really understand it yet, but we're learning."

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This article was published by S&P Global Market Intelligence and not by S&P Global Ratings, which is a separately managed division of S&P Global.