Rachel O'Bryan was campaign manager for Protect Denver's Atmosphere, which opposed Initiative 300, the local ballot measure that will allow specially licensed businesses in that city to create consumption areas for customers who bring their own cannabis. In a recent interview with Westword, O'Bryan raised several objections to the initiative, which was supported by about 54 percent of voters in last week's election. If her points are representative of the arguments deployed against Initiative 300, it's no wonder the measure passed. For instance:

1. "First and foremost, 300 is about bringing your own marijuana anywhere. But how we're going to train these businesses to understand intoxication when they neither serve the marijuana nor have any control of its potency is beyond me."

Under Amendment 64, the legalization initiative that Colorado voters approved in 2012, adults 21 or older already are allowed to carry up to an ounce of marijuana when they are out and about. Initiative 300 finally lets them consume that marijuana outside their homes, something the city has stubbornly refused to allow until now. But consumption will not be legal just "anywhere"—only in businesses that choose to allow it and obtain a permit from the city, which requires support from an "eligible neighborhood organization" such as a business improvement district or a registered neighborhood association.

A bring-your-own-cannabis (BYOC) consumption site is no different in principle from a bring-you-own-bottle restaurant or club. In both cases the establishment does not sell the intoxicant but still must deal with the potential problems associated with intoxicated patrons. Under Initiative 300, no business owner is forced to assume that burden, but any who think allowing cannabis consumption will attract customers are free to do so, provided they get the requisite approvals.

2. "You've also got the issue of mixing marijuana and alcohol, where impairment can be greater than using either of them alone."

Bar patrons have been mixing marijuana and alcohol for many years (albeit surreptitiously), so it's not as if this issue is new. But under Initiative 300, neighborhood organizations have the power to block cannabis consumption permits for businesses that sell alcohol or demand a policy that prevents BYOC customers from ordering drinks. They also can set various other conditions through "good neighbor agreements," including advertising restrictions, employee training requirements, limits on outdoor smoking, restrictions on operating hours that go beyond the initiative's ban on consumption between 2 a.m. and 7 a.m., and policies aimed at preventing impaired driving, such as a requirement that BYOC customers arrange transportation in advance.

3. "They'll also have to deal with slow-acting edibles, where the effect may not peak for four hours. How do they deal with that? Are we going to have to keep people locked up for four hours before we can assess impairment?"

Consistent with the Colorado Clean Indoor Air Act, Initiative 300 will allow pot smoking only in outdoor areas (which cannot be visible from the street), with the possible exception of cigar bars and tobacconists that decided to welcome cannabis consumers. Indoor consumption generally will be limited to vaporizers and edibles. It's not clear how popular the latter option will be, for precisely the reason that O'Bryan mentions: The onset of the psychoactive effects is unpredictable and may take longer than the customer's visit. In any case, if the issue is whether someone suspected of stoned driving is impaired, it's his condition while behind the wheel that matters, not his THC blood level four hours later. While there is no scientific basis for relating specific THC blood levels to degrees of impairment, that problem applies to any source of THC, not just edibles.

4. "When you're outside, how do you vent the air for odor?"

The same question applies to outdoor tobacco smoking, which Denver nevertheless manages to tolerate on bar and restaurant patios. If a neighborhood organization thinks a whiff of marijuana smoke is uniquely offensive, it can set conditions to minimize that risk, including restrictions or bans on outdoor consumption.

5. "Indoors…vapors, while different from smoke, may have health concerns as well…You have pollutant issues on surfaces, and we believe there may be other risks involved."

It seems quite unlikely that any measurable harm will be traced to these vapor-related "pollutant issues." But anyone worried about that possibility can always stay away from businesses that allow marijuana vaping.

6. O'Bryan fears portions of the city that didn't vote in favor of 300…may find themselves being forced to play host to pot-friendly enterprises.

Requiring approval from a recognized neighborhood association is aimed at alleviating such concerns, which in any event are no more legitimate than complaints about any other business that offends some people. In the absence of measurable nuisances, such discomfort should not stop business owners from catering to cannabis consumers if that is what they want to do. Their success depends not on "force" but on the voluntary choices of people who patronize or avoid their businesses.

7. She feels that the new measure violates both the spirit and the letter of [Amendment] 64, which "said that consuming openly in public isn't permitted."

Amendment 64 did not legalize "consumption that is conducted openly and publicly," which remains a petty offense punishable by a $100 fine. But the meaning of "openly and publicly" is a matter of dispute, and consumption on private property in an area that is open only to adults 21 or older and is not visible from the street does not seem to fit that description.

Reason TV covers Colorado's cannabis consumption conundrum: