It is a challenge for operators, as well as regulators, to stay current with the rapidly evolving and scaling commercial cannabis industry. This includes choosing the most efficient, effective and safe emissions mitigation technologies for commercial operations with a thorough understanding and consideration of the environmental factors at play. With a growing number of air quality and odor concerns from the communities around cannabis cultivation sites, managers are under pressure to install best available control technology. However, what may be effective mitigation solutions in other industries is not necessarily appropriate or safe when considering the makeup of the air in a commercial cannabis facility. An example of the misapplication of technology is Photocatalytic Oxidation (PCO). 

Risks of PCO for Cannabis Emissions Control 

Many industry players, including manufacturers of control technologies think Photocatalytic Oxidation (PCO) is a solution for odor and emissions control at large-scale cannabis operations. However, simply put, PCO is not designed for or effective at removing odor molecules from the air and in fact, under certain conditions, some PCO systems can produce byproducts, such as aldehydes, which are known carcinogens. PCO technology is widely accepted for use in many settings, such as hospitals, casinos and airplanes; however, it has not been conclusively proven to be safe or effective for controlling cannabis emissions, especially in the growing environment. 

As noted above, PCO technology is not meant for odor control. Rather, it is an engineered process to capture harmful airborne pathogens and other chemicals in the air to improve indoor air quality. Unfortunately, facility managers are often sold on the idea of PCO as a solution for odor control and with the cannabis industry evolving and research still underway, supplier vetting is often infeasible or even ignored.  

For example, when considering third party test results for a photocatalytic oxidation system prior to installation at their facility, commercial cannabis operators should be sure to note if the testing of the PCO unit was done in a mostly equivalent setting to their own. This is important because, even the safest PCO technology can be impacted by the extremely high relative humidity levels and high VOC concentrations within a grow operation, potentially causing the production of secondary byproducts.  

The Current State of PCO Research and Regulations

While there is a lack of published data on photocatalytic oxidation applications within commercial cannabis grow operations, there is abundant scientific literature on the limitations and concerns surrounding the technology. Moreover, the Environmental Protection Agency (EPA) cites a study that was conducted in 2007 and was limited to evaluating portable air cleaners using PCO, which found that portable air cleaners using a particular outdated type of PCO technology generated potentially harmful byproducts such as formaldehyde, acetaldehyde, nitrogen dioxide, and carbon monoxide. Furthermore, the EPA states “portable PCO air cleaners can also generate ozone when used with a UV-C lamp that lacks a coating to inhibit ozone generation.” Further, it is worth noting that the Santa Barbara County (California) Air Pollution Control District (APCD) specifically advises against the use of PCO for commercial cannabis odor mitigation in its April 26, 2019 APCD Advisory on Air Quality and Cannabis Operations. The fact is, PCO technology is not an odor control solution and has not yet been sufficiently tested in commercial cannabis cultivation operations to be considered a best management practice for air quality control. 

A deeper understanding of the technology and its third-party testing is necessary to know what PCO technology could effectively mitigate cannabis VOCs, and in what particular environments, without producing secondary byproducts. 

A Safe and Effective Alternative to Photocatalytic Oxidation

A safe and effective solution for improving indoor air quality (IAQ) at commercial cannabis operations is Byers Scientific’s latest offering, ASPRA® by VFA Solutions. ASPRA® is state-of-the-art patented Dutch electrostatic precipitation and filtration technology using closed positive ionization in combination with open structure filters to safely and effectively kill and capture most airborne pathogens (including viruses and bacteria). Used in conjunction with the Byers MT-6™ industry-leading activated carbon technology, a system featuring ASPRA® can help commercial cannabis operators address both odor and IAQ at the same time. 

Contact us today to learn more about safe and effective solutions for your emissions control needs.