bio-contaminants in cannabis, contamination remediation

Effective Cannabis Contamination Prevention

by | Jun 24, 2022

bio-contaminants in cannabis, contamination remediation

Written by Casia Lanier

Most cannabis users and non-users have heard stories of contaminated cannabis in one form or another, from a UK woman dying from eating an edible to the development of lymphatic cancer among growers with exposure to an undisclosed presence of butanol in what was thought to be natural, neem oil pesticide. It’s clear the industry does not have effective cannabis contamination prevention. And while this could potentially harm the already precarious public and legislative perception of cannabis, solving the contamination problem can ensure the success and longevity of the industry as well as public health.

What Kind of Cannabis Contaminants Are There?

An estimated 69% of pesticides applied during cultivation remain in cannabis during smoking, creating toxins.

A systemic review of the effects that cannabis contaminants have on human health found the most common contaminants to be microbes, heavy metals, and pesticides. This not only affects consumers, but growers, manufacturers, and cannabis brands. The pharmaceutical application of cannabis is especially sensitive to contaminants, where purity is an absolute requirement for health treatments.

Cannabis Contamination Prevention

Contamination can occur at any point between sowing seedlings and the shelf, including when chemical solvents are introduced to the plant material during the extraction period.

Some examples of documented contamination include:

  • Microbes: Bacteria and mold, including Aspergillus, Salmonella, and E. coli.
  • Heavy Metals: Lead, arsenic, and mercury from agricultural fertilizers and metal coils found in e-vaporizers.
  • Pesticides: Unregulated levels of banned Category I pesticides used in cannabis.
  • Chemical Solvents: Butane, propane, and alcohol during extraction.

The staggeringly high level of these carcinogenic substances in both ingestible and inhalable cannabis products is concerning, but what is even more concerning is the gross lack of testing mandates perpetuating this issue in the industry.

Kim Stuck, former Denver City health inspector and current CEO of cannabis compliance and strategy consultancy, Allay Consulting, emphasizes that this problem is not just the fault of the grower or manufacturer but the government.

“The FDA has one job to protect consumers from unsafe products. And right now, they’re failing to do that for a $30 billion industry. And that, from a public health standpoint, is terrifying,” challenged Stuck.

Stuck insists that growers and manufacturers are missing out on mitigation and elimination know-how because of the FDA’s inability to establish guidelines, positing that “pushing this education out to people, once they understand, they know how cannabis works with toxins and contaminants,” and can therefore take action to establish controls for them.

How To Implement Cannabis Contamination Prevention

While there are many potential sources of contamination throughout the lifecycle of the cannabis plant, there are three simple yet impactful ways to mitigate and prevent contamination from its various sources.


Unbeknownst to many workers in the cannabis industry, buildings can pose an incredibly likely point of contamination. Facilities – especially former agricultural facilities and manufacturing buildings – that have been converted into cannabis operations may house many pesticides and agricultural byproducts that “leech into the walls and the boards and the concrete. And when you put new plants in there, they can get contaminated from the building itself,” says Stuck.

Manufacturing facility implements
 Cannabis Contamination Prevention

Stuck goes on to highlight the importance of ensuring a sound and neutral facility before growing or processing cannabis, including the tearing down of and replacing drywall and sealing floors, in addition to addressing the flow of the facility so that contaminants “like powdery mildew, or spider mites aren’t being dragged through the cleanroom and mom rooms where those vegetative plants come from.”

Maintaining good manufacturing practices (GMP) can help ensure that buildings are in line with FDA standards for food safety. This might include the positioning of cleaning facilities within a building, the use of PPE, and the implementation of safe handling and processing procedures.

Training Staff

Training staff goes hand-in-hand with the GMP guidelines that facilities implement, ensuring that growers and handlers understand and regularly practice safety measures such as the wearing and changing of PPE when transferring through various rooms and hand washing.

Growing and manufacturing operations can also follow the occupational standards and health administration (OSHA) guidelines by “training all staff correctly because it only takes one person to write to make somebody sick,” says Stuck.

Waiting on the FDA

The cannabis industry is distinct from the agricultural industry. Flowers and trichomes can’t be washed of pesticides before consumption or inhalation as grapes can. Once inhaled, those pesticides go “directly into your lungs directly into your bloodstream,” reminds Stuck. Therefore, regulating what pesticides can be used for cannabis cultivation and establishing legislation for the thresholds and testing procedures for those toxins on a governmental level is key to preventing contamination across the country.

“FDA regulations are being written right now,” says Stuck, and “the minute that the FDA comes out… the companies that are going to be around, for the long haul, are those following some kind of food safety standards and OSHA standards as well.”