Kevin Parkinson ignites slow-burning forest fires with a special kind of ammunition — thousands of tiny fireballs shot from the air into the trees below.

Spewed from the mouth of a metal box, the spheres cascade through the treetops before hitting the forest floor and bursting into flame.

The process involves items that look like Ping-Pong balls, and “the Ping-Pong balls are filled with potassium permanganate,” Parkinson said. The machine injects glycol — antifreeze — into each ball before dropping it onto the ground.

“After about 25 to 30 seconds, it creates a chemical reaction inside the ball and the ball will catch on fire,” said Parkinson, in an interview for the CBC podcast World on Fire.

Parkinson, a wildfire operations officer based in Slave Lake, Alta., is one of the few people in the province trained in the complex physics of prescribed burns.

Read more on this story at CBC Canada