From the article:

>>>"such establishments would need an exemption from the Oregon Indoor Clean Air Act, which bans smoking in indoor public places, including bars, restaurants and fraternal organizations."

Not really.  -   They just need revisit that act and remove the nonsensical inclusion of vaporizers.  -   There is simply no harmful material that comes from exhaled marijuana vapor.  It does not include the few irritants that near harmless marijuana smoke has, and the active ingredient, THC, is more than 90 percent absorbed in the first-hand consumer's inhalation.  -  More harmful chemicals escape from the vaporizers of asthmatics.

So, the logical model for this kind of business would be a well-ventilated vapor lounge indoors, with a smoking area on an outdoor patio or rooftop garden.