Types of Microbial Control Solutions for Cannabis

What They Are, How They Work, and the Best Option for Your Operation

Making cannabis a Schedule III drug will allow the Food and Drug Administration (FDA) eyes into cannabis operations for the first time. They’re expected to implement strict manufacturing standards that parallel those currently required for other agricultural and pharmaceutical sectors. 

One of those manufacturing standards will be remediation requirements for microbial contamination. Operators without a kill step in their SOPs will need to add one to ensure compliance with the new federal regulations.

There are several remediation technologies to be considered, each with its own pros and cons. Keep reading for a breakdown of each to determine which is the best choice for your operation.

Ionizing Radiation Technologies

Ionizing radiation reduces microbial contamination by irradiating the product. While these are popular technologies that many producers in agriculture use, they’re not always considered safe as they alter the molecular structure of whatever they’re irradiating. In cannabis, irradiation has been shown to alter terpene and moisture content[1], and in some cases, it’s also altered the anti-proliferative compounds of the plant[2] i.e. those that may fight against certain cancer cells.

In certain countries, like Canada for example, any product treated with ionizing radiation must be labeled with the Radura, the international symbol for irradiation. In the US, the FDA requires whole foods that have been irradiated to be labeled with the Radura. This requirement may extend to US cannabis once the reschedule is in effect. US states like Nevada have also been considering the same requirement for cannabis.

Gamma Radiation

Gamma radiation has been used in agriculture for decades, particularly with meats, fruits, and vegetables. It’s also a well-established method used for sterilizing medical supplies. This technique employs high-energy photons to penetrate deep into materials, disrupting the DNA of mold, bacteria, and other pathogens to render them inactive. However, some evidence shows that this disruption leaves enough DNA intact for those microbes and pathogens to revive themselves.

Using gamma radiation in cannabis can be expensive as the process must be done entirely off-site, costing operators time and money.

Electron Beam (E-beam) Radiation

Like gamma radiation, E-beam radiation utilizes high-energy particles to eradicate microbial contamination. The primary difference lies in the particle type; E-beam uses electrons instead of photons. This method is known for its rapid processing times, but it doesn’t penetrate the flower as deeply as other remediation solutions, so there’s no guarantee it eliminates pathogens within the core of the bud. This can be an issue when dealing with pathogens like Botrytis, AKA “bud rot,” because it typically starts on the stem at the bud’s core.

Treating microbial contamination in cannabis with E-beam must also be done offsite, so it comes with similar added costs as gamma radiation.

X-ray Radiation

X-ray radiation falls between gamma and E-beam in terms of penetration depth and energy. This modality is advantageous for its ability to uniformly treat cannabis products whether or not they’re packaged, but it still doesn’t guarantee the core of the flower has been treated.

Operators can install their own X-ray remediation equipment on site, but additional chiller equipment is needed so there are added costs associated with this option.

Non-Ionizing Radiation Technologies

Non-ionizing radiation is considered safer than ionizing technologies because it does not alter molecular structures.

Radio Frequency

Radio Frequency (RF) treatment is a non-ionizing radiation technology that uses long, low-energy wavelengths to penetrate the cannabis flower to its core. These wavelengths create an oscillating electromagnetic field around and within the flower that generates heat, effectively destroying microbial contaminants without destroying the chemical makeup and potency of the plant.

RF treatment is particularly suitable for organic cannabis operations. Although cannabis cannot be officially designated as organic at this point, the reschedule will make this label available to cannabis operations. The FDA has already recognized RF treatment as an organic solution for other agricultural markets.

Ziel’s RFX machine has also been validated for EU GMP operations and can easily be integrated into operations looking to export cannabis to the EU. Ziel can install the RFX on-site, so you don’t have to worry about additional transportation or administration costs.

Cold Plasma

Though cold plasma radiation is non-ionizing, it’s not considered to be as safe as RF because it generates free radicals which may create health risks for consumers.

Basically, a high-voltage electrical charge is initiated within a gas. This charge then creates a cloud of electrons, ions, photons, and free radicals that poke holes in the membranes of pathogens and damage their DNA. Like E-beam radiation, it is mostly a surface-level treatment, so there is a risk that microbial contamination within the core of the flower won’t be treated.

UV-C Light

Ultraviolet-C (UV-C) light remediation uses a spectrum of non-visible, short-wavelength light to disrupt the DNA of pathogens. It attacks the core of a pathogen and prevents it from replicating. Because its wavelengths are short, it treats mostly the surface of cannabis flower and doesn’t tend to penetrate the flower’s center.

UV-C remediation can be used to treat loose flowers or fully packaged products. Additionally, because it’s chemical-free and non-ionizing, it can be incorporated into organic food operations and will likely be allowable for organic cannabis operations as well, once the FDA opens that designation to cannabis.

Chemical Remediation Technologies

There are a few chemical remediation technologies available, including ethanol, CO2, and ozone. We’re only going to touch on ozone here as it’s the most common chemical option for cannabis operators.


Ozone treatment leverages the strong oxidizing properties of ozone gas to eliminate microbial contaminants. It can be incorporated into organic cannabis operations and has a GRAS (Generally Recognized as Safe) designation with the FDA, but it does have the potential to leave residue behind on your cannabis products.

Ozone remediation treatment can vary depending on the machine you use. Many ozone generators do not allow you to control the concentration of ozone, and too much of it can be extremely damaging to cannabis flowers. Even with a more customizable machine, it is mainly a surface-level treatment that doesn’t guarantee the core of the flower has been decontaminated.

Choosing the Right Microbial Control Solution for Your Operation

As the FDA prepares to regulate cannabis operations following its federal rescheduling, incorporating effective microbial control solutions into your SOPs is going to be essential for compliance and product safety. Understanding the various microbial remediation technologies available to you is crucial for making the right decision for your operation’s future.

Among these remediation solutions, Radio Frequency stands out as the best choice for cannabis operators. RF treatment offers an organic, non-ionizing, and cost-effective method of microbial control without compromising the quality and integrity of your product.

In particular, Ziel’s RFX can set your business up for a successful future as an organic, GMP-validated operation ready to sell in the US or export across the globe. Get in touch with us today to find out more about incorporating radio frequency remediation into your business.