Oil and gas companies are concerned that the legalization of marijuana could make their work sites less safe.

Workplace safety is a big concern for the oilpatch, with workers routinely tested for illicit substances before being allowed to work with flammable and toxic materials and heavy equipment.

The Petroleum Services Association of Canada's safety arm, Enform, asked the federal government’s task force for a chance to present its concerns. One of those concerns is that marijuana stays in the body for several weeks.

“Are they looking at this from an industry aspect and are they supporting the development of tools to help employers manage the situation?” said Mark Salkeld, PSAC. “How do they deal with that? Some policies say fire them or send them to rehab.”

Those who support legalization say fears about marijuana come from outdated attitudes.

“It's mostly reefer madness they're throwing out there in my opinion,” said Keith Fagin, Calgary 420. “We need to start looking at lack of sleep and pharmaceuticals, we're putting this all on cannabis and we need to become responsible adults and especially responsible leaders of industry and do some research.”

Advocates point to Colorado, where pot has been legal since 2014, and now sees fewer traffic fatalities, countering concerns about high drivers making roads unsafe.

While public consultation on the legalization of pot is now closed, the task force could still hear from the Canadian Association of Petroleum Producers, which has been consulting for the federal government on industry concerns. The task force will present its report to ministers in November.