Last Friday, a week and a half after Denver voters approved an initiative allowing cannabis consumption in local businesses, the Colorado Department of Revenue's Liquor Enforcement Division announced that businesses it regulates are prohibited from participating in the pilot program. That means bars and restaurants with liquor licenses can't legally let customers bring their own marijuana to enjoy on the premises, as envisioned by supporters of Initiative 300, which was favored by 54 percent of voters.

The department said the new rule has been in the works since last year, prompted by the liquor industry's concerns. Although that sounds like special pleading from manufacturers and distributors worried about competition from another intoxicant, DOR Executive Director Barbara Brohl said the ban is all about safety. "After carefully considering all impacts to Coloradans and industry," she said, the department decided "this rule is in the best interests of public health and safety resulting from public and dual consumption." The Colorado Restaurant Association said it also "expressed concerns about the public dual consumption of marijuana and alcohol," which suggests that some restaurateurs worried that their competitors might attract customers by offering a BYOC option.

Larry Wolk, executive director of the Colorado Department of Public of Public Health and Environment, supports the DOR's decision. "There is substantial evidence that combined use of marijuana and alcohol increases impairment more than use of either substance alone," he said. "If marijuana use is allowed in establishments that hold a liquor license, dual use certainly would occur regularly and present a danger to public health and safety."

The rule eliminates one of the major arguments against Initiative 300, but at the cost of consumer choice and business flexibility. Daniel Landes, owner of the City O' City restaurant and bar in Denver, told the Associated Press he'd like to be able to hold special events where cannabis consumption is allowed. "I'm in the hospitality business, and there is no place like this to use marijuana," he said. "That is inhospitable." Since the rule applies statewide, even bars and restaurants in jurisdictions that have been more tolerant of cannabis consumption than Denver will be risking their liquor licenses if they let customers use marijuana.

Denver businesses that don't sell alcohol, such as cigar bars, yoga studios, art galleries, newly created cannabis clubs, and restaurants without liquor licenses, can still seek permission from the city to create "designated consumption areas," providing a new option for residents and visitors who have struggled since legalization to find social settings outside the home where they are allowed to use the marijuana they are now allowed to buy. Permits are contingent on approval by an officially recognized neighborhood organization, which can demand restrictions in addition to the ones imposed by Initiative 300.

The DOR rule "doesn't completely hinder the entire law," Mason Tvert, an organizer of the initiative campaign, told The Denver Post. "Remember that this whole thing kind of got started with the Colorado Symphony Orchestra fundraiser that was held in an art gallery." I cited that episode as an illustration of Colorado's cannabis consumption conundrum in a 2014 Reason feature story. Reason TV has covered the issue too: