Cannabis Contaminants: Identification, Testing, and Prevention

There are many common cannabis contaminants and pollutants, in both home grows and commercial cultivation operations.

These contaminants are often chemical or biological in nature and can range from molds, fungi, and heavy metals to residual pesticide residue.

These pollutants can have a wide range of causes, with improper growing and manufacturing practices, improper curing or storage, high humidity, improper temperatures, impure water, and the application of noxious chemical pesticides being the most common causes.

For all of these pollutants, sound cannabis cultivation practices and procedures will minimize, if not eliminate, many of the problems.

The presence of pollutants and contaminants should not normally occur, so their presence indicates some changes should be made. Remember, prevention is the best medicine.

Most Common Cannabis Contaminants

Mold and Mildew on Cannabis

The most common cannabis pollutants include white powdery mildew and mold.

White powdery mildew looks much like its name implies. The surface of the cannabis plant looks as if it’s been dusted with flour—which looks very different from the white, sticky coating of trichomes that cover the surface of flower.

Mold is easy to spot as well, but has quite a different appearance. It most often affects the surface and nooks and crannies of flowers, and looks like fine, clumpy spiderwebs.

Mold can also affect other areas of the plant, including the leaves, especially if there are large shade leaves resting on the surface of other leaves.

Both white powdery mildew and mold are usually preventable, and if they should strike, some cultivation practice modifications will usually rectify the problem.

Overly high humidity and temperatures that fluctuate usually contribute to an outbreak of these cannabis contaminants.

Heavy Metals and Residual Solvents on Cannabis

These contaminants are not visible to the naked eye but their presence is easy to detect through the implementation of specific tests.

Unacceptable residual solvents can occur during the manufacturing and production of cannabis concentrates. Products like oil, shatter, wax, and crumble are often made with the use of solvents like alcohol, butane, propane, and carbon dioxide.

Some extraction methods, if done improperly, can result in high residual solvents like butane or propane. The goal of all extraction operations is to produce concentrates high in cannabinoids and terpenes, but low in residual solvents.

In addition to individual companies doing their own independent testing, independent cannabis testing labs also are an option in some areas of the country, and third-party testing is often a requirement of cannabis regulations.

Cannabis contamination occurs also with heavy metals, especially from the soil. However, it also sometimes comes from shatters and concentrates.

Pesticides

Research has revealed that the utilization of these substances is widespread, with significant levels of pesticides being transmitted into cannabis smoke.

Among the most prevalent pesticide categories linked to cannabis are insecticides, acaricides, and fungicides.

There exists over 350 distinct pesticide products authorized for use on cannabis, with 16 pesticides and three plant growth regulators (PGR) being identified as primary contenders.

Your best bet to steer clear of pesticides is to buy organic cannabis.

Businesses Providing Testing for Cannabis Contamination

Modern Canna provides testing for pesticides, solvent residue, and microbiological contaminants in cannabis.

Medicinal Genomics provides PathoSEEK® Microbial Safety Testing kits.

Belcosta Labs is a compliance testing facility located in California that offers cannabis farmers professional guidance as well as microbiological testing on cannabis.

Willow Industries offers products such as the WillowPure system and specializes in cannabis decontamination technologies.

Final Thoughts on How to Prevent Cannabis Contamination

The best way to prevent cannabis contamination is to buy your cannabis from regulated dispensaries.

To learn more about the medical effects of cannabis and how to grow clean cannabis, enroll in Cannabis Training University's online cannabis certification today!