The burning question about precisely where a person can smoke these days is flaring up again in Ontario, where a 48-year-old trucker faces a $305 fine for lighting up on the job: while driving his big rig along Canada's busiest highway.

The man, who hails from London, Ont., was headed for Windsor when he was pulled over Wednesday along Highway 401 and given a ticket under the Smoke-Free Ontario Act.

The law, considered a Canadian standard-setter when it was passed in 2006, forbids smoking in all workplaces and enclosed public spaces, including buildings, structures or vehicles worked in or frequented by employees, according to the government's website.

"Examples of an enclosed workplace include the inside of a trailer office on a construction site, the inside of a loading dock, or the inside of a delivery truck," the site says.

Ontario Provincial Police Const. Shawna Coulter said the law is very explicit about what constitutes a workplace.

"It says the inside of any place, building, structure or vehicle that is part of the employee's workplace, which if you're driving a truck for long periods of time – that becomes your workplace."

The driver, whose name was not released, could have good reason to fight the ticket in court, said Doug Switzer, vice-president of the Ontario Trucking Association.

The provincial law ought not to apply in the case of federally regulated trucking companies that operate in other provinces or the United States, Switzer said – nor should it be brought to bear on truckers who own and operate their own rigs and work alone.

"It is a little complicated on the enforcement end because you've got thousands of people from OPP, municipal police forces and health unit enforcement staff, not all of whom are versed in the subtle nuances of the trucking industry or the smoking legislation," he said.

Julie Rosenberg, a spokeswoman for Ontario's Ministry of Health Promotion, refused to comment Thursday on whether or not the law would apply in the case of a truck belonging to a federally regulated company.