Electric vehicle battery fires remain poorly understood as mining industry transitions to the technology

As northern Ontario's mining industry transitions to battery electric vehicles (EVs), safety experts say the risks posed by battery fires remain poorly understood.

At a symposium in Sudbury on those risks, organized by Workplace Safety North, Norm Ladouceur said that while there are many benefits to using EVs in mining, if they catch fire, it could be challenging to manage.

Ladouceur is the corporate manager of health, safety, security and emergency response for Agnico Eagle Mines, which operates two gold mines in northern Ontario.

Since 2022, Ladouceur said, the company has had five battery fires at the surface and one electric vehicle fire underground.

In one case, he said, when lithium ion batteries are exposed to water, they can spontaneously combust. 

Because battery recycling is not yet readily available, he said that experience has shown the importance of better long-term storage for spent batteries, where they can remain dry.

Ladouceur said when diesel vehicles were first introduced in mining, the industry had to adapt with new safety procedures.

The same thing is happening now with EVs.

"We're starting to understand the risk associated with having this equipment," he said. "We're seeing that if they catch fire that we may not have a total solution to put those fires out."

Mining companies are starting to use EVs because they provide a number of benefits, especially underground. They aren't as noisy as diesel vehicles, which means workers are less likely to sustain hearing damage.

EVs also don't emit fumes, which can lead to workers breathing in diesel particulates. With no fumes, underground ventilation systems don't have to recycle and clean the air as much, which can also save companies money.

But when batteries catch fire, Ladouceur said, we still don't fully know which gases are emitted.

That means the personal protective equipment (PPE) that underground firefighters use while dealing with diesel fires might not be sufficient to keep them safe.

"Once we fully understand what gases are involved emitting from a battery fire, we may be covered," Ladouceur said.

"I can start by saying that, but we don't know. And until we do fully know, then we need to keep digging."

He said it's important for mining companies to share safety information with each other, even if it means revealing on-site issues such as equipment catching fire.

Justin Arsenault, the fire chief at Agnico's Detour Lake Mine northeast of Timmins, said it takes a lot of water to put out lithium ion battery fires, and they can reignite even after they're doused.

As EVs become more common in mining, Arsenault said, fire crews are experimenting with new technologies to fight fires more efficiently. One example, he said, is a new eco gel.

"We're just starting to touch the batteries where this gel tends to bind on whatever it is that it touches, snuffing out pretty much anything that it gets to, but also uses a lot less water."

Arsenault said training fire crews on how to deal with battery fires and developing best practices will be important as the industry continues to transition to the technology.