Transport Canada has released its regulations surrounding cannabis for workers in the aviation industry.
Pilots, cabin crew members and air traffic controllers have been informed that, to maintain "fitness for duty" on the job, they must be free of cannabis for four weeks - 28 days - before being able to work, reports the CBC.
The regulations are effective immediately.
CBC also points out that airports and airlines will be able to place stricter requirements on cannabis, if they choose.
Last October, the Royal Canadian Mounted Police announced a similar policy, stating that "employees in safety-sensitive positions must refrain from using non-medicinal cannabis 28 days prior to reporting to work."
Tom Stamatakis, President of the Canadian Police Association, called this "an offensive approach".