Air quality is something cannabis farmers think about a lot. Some neighbors love the floral scent of cannabis. Some consider it a nuisance and would describe it as “skunky.” Whatever the case may be, Santa Barbara County has strict regulations for cannabis odors. CARP Growers has used a 3-pronged approach to combat odors: odor abatement, research and monitoring.

Each member of CARP Growers has vapor-phase odor control. That means a thin vapor curtain of essential oils is emitted around greenhouses. These essential oils have terpenes, just like cannabis, and are formulated to interact with cannabis terpenes and neutralize them. We fight terpenes with terpenes to create neutral scents.

Fixing Odor Issues with Vapor-Phase Odor Control

The local dialogue about odor issues has been one that farmers have taken very seriously. Neighbors spoke out back in 2016 when cannabis odors in Carpinteria Valley were pervasive. Most importantly, our local school district asked for changes. Local farmers looked far and wide for the best solutions and made necessary changes.

There’s still work to do, but at CARP farms where greenhouses use vapor-phase odor control by Byers-Scientific (see video on Byers at our Inside Look page), odors have been effectively eliminated.

A study conducted by SCS Engineers found the Byers vapor-phase system to be 98 percent effective. Air samples were taken at three distances outside greenhouse operating the vapor-phase system. The samples were then tested by odor experts at a third-party laboratory. Odors were found to be well below levels that typically reach the threshold of a public nuisance. Also noteworthy, analysis found that carbon filtration is less effective because carbon filters wear down quickly and lose efficacy.

What’s a Volatile Organic Compound?

Those opposed to cannabis cultivation feared that cannabis produced Volatile Organic Compounds, and these VOCs impacted the environment. First a word on VOCs. They are everywhere: in fennel, pine and lemon trees; in the ocean and in bad breath and body odor. Biogenic VOCs, those produced naturally, are not harmful. Some VOCs, like those in paints and petroleum, are harmful and the EPA regulates them. You see warning labels on solvents about VOCs.

To ease worries that plant VOCs cause issues, we asked Dr. William Vizuete, a nationally known atmospheric molecular chemist, what impacts cannabis farming could have in Santa Barbara County.

Dr. Vizuete explained that in some instances, an abundance of biogenic VOCs can mix with NOx pollutants and form ozone. However, the amount of acres of cannabis grown locally produces negligible amounts of VOCs. In Santa Barbara County, there are about 39,042 tons of Biogenic VOCs emitted into the air by plants each year. Cannabis adds 50 tons annually, bringing the overall number to 39,092. In the big picture, that’s not a huge change.

The other component needed to create pollution from Biogenic VOCs is NOx. Dr. Vizuetes analysis found that NOx is not present at levels in Santa Barbara to create ozone pollution. We’re glad the study is out there, because discussion about VOCs and NOx can be intimidating.

Santa Barbara County Air Pollution Control District also researched the topic and found really good news. Santa Barbara County has the lowest levels of ambient NOx it has had in 40 years. For the first time in 40 years, the county has not had to issue air quality warnings due to high levels of NOx.

The finding is unrelated to cannabis farming. That is to say, cannabis farming has not cleared the air of NOx, but with such low levels, there is nothing to worry about from VOCs related to cannabis or other plants like lemon and pine trees, which produce far greater volumes of VOCs.

Nasal Ranger Data Collection

CARP Growers research assistant Sydney Pahle conducts odor testing two times per week all around Carpinteria Valley. She uses a device called a Nasal Ranger that compares odors near cannabis farms to carbon-filtered ambient air. This allows us to continually monitor odors and make adjustments as necessary.

3-pronged solution

As an association of responsible farmers, CARP Growers has used a 3-pronged approach to combating odor issues. We’ve implemented vapor-phase odor control that works safely and effectively. We’ve used scientific data and research to determine that cannabis farming does not create air pollution. And we stay on top of odor complaints while proactively monitoring odor. That way, our members can hold each other accountable and make sure we can all breathe easily, especially our neighbors.