OTTAWA -- Eighteen-year-olds should be allowed to buy recreational cannabis when the Liberal government launches a globe-leading social experiment in legalizing marijuana next year, a federally appointed task force said Tuesday.

The age limit -- and the hazy science of pot-impaired driving -- were among the most contentious aspects during five months of hearings and research, task force vice-chair Dr. Mark Ware told a news conference in the parliamentary precinct.

is recommending storefront and mail-order sales to people 18 and older, with personal growing limits of four plants per person and a 30-gram limit on personal possession.

No other major western country -- with the exception of Uruguay, population 3.5 million -- has fully legalized and the world will be watching.

The green light for teenagers helped boost stock prices for marijuana producers on the Toronto Stock Exchange and produced a sharp exchange in the House of Commons, where Prime Minister Justin Trudeau defended his government's policy direction without committing to following all the task force's 80-plus recommendations when legislation is introduced next spring.

"Right now kids have easy access to cannabis across this country. We need to change that," Trudeau said of his government's two cannabis-related policy priorities.

"Secondly, to remove the source of significant revenue to criminal organizations and street gangs who benefit for the illicit trade of cannabis."

The 106-page framework covers everything from advertising and branding -- effectively banned, similar to tobacco -- to penalties for illicit production and trafficking, all legislated under a proposed new Cannabis Control Act.

And it says the current medical marijuana regime should remain in place, at least until the legal recreational market dynamics play out.

The overall direction of the task force was never in doubt as it toured legalized U.S. states Colorado and Washington.

Its chair, former federal Liberal justice minister Anne McLellan, said the nine members wouldn't have taken the job if they didn't believe in ending marijuana prohibition.

"As a matter of public policy," said McLellan, "legalization now is the time to move away from a system that for decades has been based on prohibition of cannabis, into a regulated legal market. I think we're all aware of the challenges and societal problems that the existing system has created."

The report's 80 recommendations are all geared, one way or another, to creating "a viable legal market, which will be essential to meet the government's objective of displacing the entrenched illicit market that exists in Canada today," said McLellan.

She said the report recommends a "public-health approach to minimize harm," as well as actions "to educate Canadians ... to increase awareness and knowledge" about cannabis and its impacts.

Reaction to the report was as varied as the public input the task force received.

"Age 18 means you can be in high school and legally smoke marijuana," Pamela McColl, of the prohibitionist group Smart Approaches to Marijuana Canada, said in an email. "We have lost our way as a country."

Jeffrey Lizotte, CEO of Next Wave brands, which advises the budding industry, said almost every cannabis-related stock listed on the TSX rose Tuesday.

"Most expected the age of majority to be between 21 and 25, where people had recommended," Lizotte said in an interview.

"Luckily they took a more evidence-based approach. They understand that most consumers are aged 18-25, so if you exclude them from this market they'll go to the black market."

The Canadian Medical Association issued a statement lauding the overall approach to "non-medical" marijuana regulation.

But the CMA said the task force missed the mark in recommending a distinct medical regime, given what it says is the limited clinical evidence for medicinal cannabis.

Ian Culbert of the Canadian Public Health Association called the report "an important first step towards establishing a retail framework that strikes a balance between freedom of choice and health protection."

Police forces remain somewhat skeptical, with Saskatoon police chief Clive Weighill typifying the cautious reaction.

Weighill said roadside tests for marijuana may not paint a clear picture of impairment, and suggested a black market in cheaper-priced pot will continue.

Current producers of medical marijuana said the task force's hard line on marketing, packaging and branding still needs some work.

Bruce Linton, CEO of Canopy Growth Corp., said the consumer demand for information should trump the recommendation to list levels of only THC and CBD on recreational pot.

Linton says limiting package information won't tell consumers "whether this will make you euphoric or contemplative or sleepy."

"My competitors over the years have largely used innocuous packaging as well -- called zip-lock baggies," he said. "Is that really what we're trying to do?"

Linton says the world will be watching Canada's efforts as a leader in managing what is a global black market problem and medical research opportunity.

"I still think Canada being Canada -- and doing this -- has not been fully appreciated," he said.