West Boundary firefighters responded to a super-chilled incident on Highway 3 Wednesday, Oct. 6.
A thick cloud of what appeared to be white smoke was seen peeling off a large tank in back of a tractor-trailer parked on a roadside pullout east of the village. Mike Daloise, Chief at Midway Fire and Rescue, said the smoke turned out to be nitrogen gas, the natural and generally harmless byproduct of liquid nitrogen warming up in the tank.
The driver had parked safely and had kept passersby well away from the gas when Daloise arrived on-scene shortly after 8:30 a.m. The gas had been properly ventilated through the trailer’s purpose-built tank, he explained, likening what happened to so much steam being let-off through a release valve.
Nitrogen expands about 700 times in volume when it changes from a liquid to a gas. Nitrogen gas can suffocate people if it builds in confined spaces, but not when it’s vented into the open air, he said.
“It was any definitely an interesting call,” Daloise joked, assuring that gas posed no threat to health and safety.