One way to remove some of that subjectivity is to use devices called field olfactometers, which offer science-backed data about the intensity of odors.
McGinley's lab makes a field olfactometer called the Nasal Ranger. It looks like a telescope with a mask on the skinny end and a rotating dial on the fatter end. Users adjust that dial, then hold the Nasal Ranger up to their nose and breath in. Carbon filters purify some of the air. Then, based on the dial's setting, the device mixes the filtered air with the air coming in from outside before it gets to the user's nose. The more dilution required to get rid of the smell, the stinkier the outside air would be.
Denver has set odor standards for marijuana and other stinky businesses based on the measurements tracked by the Nasal Ranger and similar devices. But for now, many California cities and counties rely on repeated complaints as evidence of a problem.
In Santa Barbara County, for example, if county authorities get three odor complaints from a business in a year, the company must take steps to fix the problem. And if the business doesn't stop the stench, the county may revoke local permits.
"There's going to be a tough learning curve," Jensen said. "Time will tell whether this becomes an issue."