How Breakthroughs in Cannabis Odor Research Can and Should Shape Odor Control Policies

by Byers Scientific | July 28, 2021 | Blog | Cannabis

Commercial cannabis is a booming industry with incredible profit potential. By 2026, experts predict the legal U.S. cannabis market will reach $41 billion in annual sales, making it roughly the same size as the craft beer industry. And considering strains with a strong “skunky” odor are some of the most popular on the market, there’s extra incentive for commercial cannabis cultivators to selectively grow highly aromatic plants. 

Unsurprisingly, cultivation odors have caused tension between commercial cannabis cultivators and surrounding communities. Thankfully, cannabis odor research continues to experience breakthroughs that are essential to creating actionable, sustainable, and data-backed odor regulation and odor control policies. 

A foundational understanding of cannabis odor

For years, cannabis’s characteristic smell has been linked to terpenes. These naturally occurring compounds are found in many plants (and some animals), including citrus fruits, eucalyptus, and many commonly used aromatic herbs. 

Cannabis plant emissions have been found to contain over 200 different compounds. Historically, researchers suspected the distinct (and often divisive) skunk-like odor of hemp and cannabis plants was attributable to terpenes, in particular, beta-myrcene. As one of the most common terpenes found in cannabis emissions, it’s a convenient culprit. However, this understanding of cannabis odor paints an incomplete picture. 

Recent breakthroughs in cannabis odor research

In March 2021, a research team including Byers Scientific, Iowa State University, and Texas-based odor experts announced a landmark discovery. Through a triangulation approach of analytical chemistry, leaf enclosure study, and field observation, the team of researchers was able to isolate, identify, measure, and ultimately conclude that rather than a terpene, the compound 321-MBT is the primary source of the distinctive cannabis odor.

The impact on cannabis odor regulation policies

Knowledge is power, and we still have plenty to learn when it comes to understanding cannabis odor and how best to mitigate its impact on communities near cultivation facilities. While this recent discovery represents significant progress in the scientific understanding of cannabis odor, it’s just a first step.

For example, leaf enclosure studies performed by Byers Emissions Analysis reveal other thiols present in the plant emissions. Any number of these could also contribute to cannabis odors. Even more importantly, other compounds in the plant’s gas-phase emissions and atmospheric reactions may significantly affect the perception and measurement of 321-MBT. 

One crucial fact that our research bears out: not all volatile organic compounds (VOCs) are created equally. Humans can smell thiols in parts per trillion, while other aromatic compounds might only be detectable in parts per million. In other words, these compounds, when present in smaller quantities in cannabis plant emissions, may be most responsible for its pervasive odor. 

Because of this, it is essential that regulators not confuse the presence of VOCs with the existence of odor. Instead, it is necessary to determine emission factors for all cannabis emissions to properly assess whether or not an odor-causing compound is actually present and causing or contributing to an odor issue. 

Byers Emissions Analysis is leading the charge

We’re proud to have a team of emissions experts at the forefront of cannabis odor research. Thanks to the invaluable work of Dr. Will Vizuete and Dr. Alex Guenther, we’re able to continue to make advances in research and technology that address our clients’ odor and emissions concerns.