Calgary police officers will not be allowed to consume marijuana once it's legalized even on their days off — and the union representing members is unhappy, saying the service "took the easy way out."

The abstinence directive was issued to CPS staff on Friday less than four weeks before recreational marijuana is legalized across the country.

"Sworn members who are qualified to use firearms and are able to be operationally deployed are prohibited from using recreational cannabis while on or off duty," reads the policy, a copy of which was obtained by CBC News.

'Path of least resistance'

The policy "pretty much covers everybody in the service," said union president Les Kaminski, adding CPS has taken the "path of least resistance."

"When our members are on a five-day-off stretch, they're not expected to carry their firearms around with them, we leave them at work," said Kaminski.

"If a person has five days off and smokes some cannabis on their first day off are they not fit for duty five days later? That's what we need to get to the bottom of."

But the senior officer in charge of the cannabis legalization effort for CPS says the service has erred on the side of safety until more research can be done into the drug's effects and metabolization rates.

Abstinence 'most logical way to start'

"It's hard to do research on something that's been illegal for so long," said Supt. Darren Leggatt, who points out policing is an inherently dangerous and unpredictable job.

"Abstinence for sworn members is really the most logical way to start."

Leggatt raised concerns about the drug's ability to impair judgment, decision-making and cognitive processes.

This is an issue policing agencies across the country have been dealing with since the Liberal government announced it was moving forward with plans to legalize recreational cannabis.

The Canadian military has not banned recreational marijuana usage by its members but instead placed restrictions on consumption. The regulations state military members cannot consume cannabis within eight hours of being on duty, and are not allowed to smoke or ingest it during the work day.

CPS may change policy in future

Kaminski says the association is looking at the new policy "with a fine-tooth comb" and believes it will look completely different 12 months from now.

"We're in the Wild West right now, there's no precedent," said Kaminski.

Leggatt is not ruling out changes to CPS policy as more research is done.

"We're very interested in partnering with an academic institution and perhaps looking at this long term," said Leggatt.

"It will evolve; this is new to us, this is new to the profession, this is new to us as an employer as well."