What causes Cannabis odour? And what can be done to mitigate it?
During certain stages of the growth cycle, Cannabis plants can produce a powerful and very distinct smell that is often unwelcome in nearby communities. With legalization, odour from Cannabis production and greenhouse facilities is increasingly becoming a nuisance issue in Canadian municipalities.
Cannabis odour comes from organic compounds produced in the plant, called Terpenes. The plants produce multiple types of Terpenes, such as Pinene {C10H16} and Limonene {C10H16}, which can be an annoyance when they are detectable. While in nature these Terpenes generally function as deterrents for predators, and may be emitted from certain types of trees, shrubs and even other crops, in a municipal setting they can become an irritation to the general public.
A wide range of industrial activities are prone to “nuisance” odours which may impact the neighbouring community, or pose an on-site problem. The Cannabis industry however is especially prone to becoming a target for odour complaints, due to it’s high profile in the news and with some community groups. When these odour complaints arise, there are two common approaches to assessing the issue: sample collection to determine odour emissions at the source, and community odour surveys.
For odour emitting from an identifiable source (i.e., a stack or vent), it may be appropriate to collect samples in order to quantify the odour. Collecting samples and analyzing them using equipment such as an olfactometer (an instrument used to quantify the concentration of odour), a trained professional can evaluate the odour issue and assess the problem. Further odour evaluations can be supported by laboratory analysis using methods such as gas chromatography for determining the concentration and speciation of specific odour causing compounds, such as terpenes.
For odour issues where source sampling may not be feasible, community odour surveys provide another option to assess the impact of odours from a Cannabis facility. A community odour survey is generally conducted by trained professionals, but plant staff or other stake holders such as community groups can also be trained to conduct the survey, if desired. During a community odour survey, when and where odour is detected, an estimate of the concentration and character of the odour, the wind speed and wind direction at the time of the observation, as well as observations related to any other possible nearby sources of odour are documented.
Combining odour emission testing with a well-designed community odour survey with representative meteorological data and atmospheric dispersion modelling are useful tools when assessing odours in order to minimize complaints and evaluate further mitigation, if necessary.
How can ORTECH help?
All of the professional services mentioned above are performed by ORTECH. We can prepare a cradle to grave solution for your facility to help mitigate cannabis related odours, proactively sample sources of Cannabis odours before they become a problem or develop community odour surveys and analysis.