Health Canada is allowing commercial medical marijuana growers to produce and sell concentrated cannabis oil, but the government says the sale of edible products like pot cookies and brownies will remain illegal.

The department announced on Wednesday that it will allow 18 licensed producers to sell the oil as well as the dried marijuana buds they have been mailing to registered patients since the medical marijuana system was overhauled last year. Producers will not be able to sell seeds or any plant material that can be used to propagate marijuana.

Last month, Supreme Court ruled 7-0 that Health Canada had no right to insist patients receive only medical marijuana that can be smoked. The court said that system subjected sick people to the risk of cancer and bronchial infections and could prevent them from choosing a more effective treatment. Oil can be used to bake more palatable forms of the drug, but advocates argue that the process is too onerous for many sick people.

Story continues below advertisement

The so-called "edibles" case is the latest major legal defeat for the Conservative federal government's war on drugs.

In its statement on Wednesday, Health Canada reiterated that "marijuana is not an approved drug or medicine in Canada and has not gone through the necessary rigorous scientific trials for efficacy or safety."

Still, it will allow licensed producers to ship unscented and unflavored oil to patients in child-resistant packaging. The packages must be clearly labelled in capital letters with "keep out of reach of children," and also says "This product has not been authorized for sale under the Food and Drugs Act. It has not been assessed for safety or efficacy to treat or prevent any disease or symptom."

The label must indicate the equivalence to died marijuana of the fresh pot buds, leaves or oil, and the growers cannot sell oil that exceeds 30 mg per millilitre of delta-9-tetrahydrocannabinol (THC), which is the psychoactive compound in cannabis. Each bottle of oil must also specify how many milligrams of THC and cannabidiol (which is reportedly one of pot's more therapeutic compounds) it contains.

The growing industry's two lobby groups praised the government's announcement on Wednesday, and several companies said they would soon offer cannabis oils to their patients.

Brent Zettl, CEO of Prairie Plant Systems Inc., the first grower licensed by Health Canada, said his customers could start getting the oil in about two months. Although Health Canada has also allowed the sale of fresh leaves and buds, Mr. Zettl said these will probably prove too difficult for many producers to ship.

"We get between three and five calls a day leading up to this [announcement] where people are asking if they can have oils," Mr. Zettl said, adding that children or seniors, who are more vulnerable to the psychoactive properties of marijuana, will benefit most from regulated medical access to oils rich in cannabidiol.

Story continues below advertisement

In its statement, Health Canada reiterated that it does not regulate the illegal compassion clubs or the dispensaries that have exploded in popularity in Vancouver over the past two years and are now popping up across B.C. and the rest of the country.

An online survey conducted last week by Insights West found two-thirds of British Columbians polled said they approved of Vancouver's new bylaw to regulate the dispensaries, and more than three quarters said they believe pot has legitimate health benefits. Less than half of respondents (41 per cent) said they supported a ban on selling edibles, such as cookies and brownies. The survey was conducted from June 28 to July 1, 2015, among 846 adult B.C. residents has a margin of error of plus or minus 3.4 percentage points.

A Federal Court ruling on the right of medical users to grow their own plants, as they did for years under the old federal system, is expected later this summer. The judge in that case has granted an injunction allowing those licensed under the old system to continue their activities until his ruling.

On Wednesday, Health Canada said those covered by the injunction may now also possess derivatives like cannabis oil for their own use.