Canadian soldiers will be permitted to consume marijuana when the adult recreational cannabis use law kicks in on October 17. The Canadian Armed Forces published new guidelines for military personnel this week after analyzing the latest research on the impacts of marijuana. Soldiers will be allowed to use cannabis, but they must adhere to a number of additional restrictions.

They cannot consume marijuana on shift or bring it onto an aircraft, and they cannot take it abroad. They must also refrain from consuming cannabis up to eight hours before work, up to 24 hours before handling a weapon or driving, and up to 28 days before joining the crew of an aircraft or submarine.

Lieutenant General Chuck Lamarre, who heads up the personnel department at the Canadian Armed Forces, said: “We’ve made the policy document very explicit as to when it can be used and when it cannot be used, and who is prohibited from using, and we go to a large extent to protect our operational capability. We believe our members are very keen on what they’re doing in the Canadian Armed Forces and they have the right ethics and morals to make sure they are available at all times and that they are not impaired by this, or any other substance. We feel very confident that eight hours, 24 hours and 28 days will ensure that we’re operational effective and will ensure that our men and women are ready at all times to do their business.”

The government published a lengthy document online that gives its members the full rundown on cannabis. It warns soldiers that cannabis consumption causes impairment of attention, cognition, mood, memory, judgement and motor skills, to a greater or lesser degree, depending on the amount of THC consumed, the user’s health and physical constitution, and the preparation and route of consumption.

“CAF members should be aware that cannabis smoke contains many of the same harmful substances as tobacco smoke and therefore can damage lungs and cause bronchitis-like symptoms, coughing and wheezing which, alone or together, can affect their overall physical performance,” says the document.

The Canadian military has a zero-tolerance drugs policy, and some had called for it to ban members from using cannabis. But it has to respect the law, and it is now treating marijuana in a similar fashion to alcohol. Lamarre has briefed military commanders from the US, Britain, Australia and New Zealand – Canada’s closest allies – and reassured them that it will not affect soldiers’ operational performance levels. He reported that there have been no negative comments in response to this issue.