Mold and mildew are some of the most common causes of hemp and cannabis contamination. Humid environments combined with the plant’s high moisture content create a breeding ground for microbiology to grow. In addition to mold and mildew, pesticides, residual solvents, non-compliant THC content are the most commonly failed laboratory tests we see at ACS. But they’re far from the only causes of corruption.

Here we review the top 5 unexpected reasons for hemp and cannabis contamination that farmers, processors, and manufacturers need to know about.

1. The Bottle or Packaging

Imagine this: you go out of your way to buy clean hemp from a reputable farmer. Then, you meticulously process the flower to create a natural, full-spectrum oil. You send the solution to a reputable third-party laboratory for analysis, and your product passes all tests with flying colors. So you bottle the solution and ship your premium-grade tinctures to stores across the country. What could go wrong?

Unfortunately, your bottle might be corrupted, and that means your end product might be too.

“The most disturbing trend we found was lead contamination in [hemp extract] tinctures,” said Holly Bell, Director of Cannabis at Florida’s Department of Agriculture and Consumer Services (FDACS)

In an interview with ACS Laboratory last year, Florida’s Cannabis Director told us she was shocked to discover several products across multiple brands contained dangerous amounts of lead. Bell’s team immediately analyzed the pattern. And through an extensive investigation, they found that adulterated bottles and droppers were to blame.

The manufacturers of these products did nothing intentionally wrong. But during transit, the bottles were exposed to high heat and sun, which degraded the materials. As a result, the corrupted bottles leaked toxic lead into the oils.

“We’re guessing the bottles are probably coming from China, but we don’t know for sure,” said Bell.

In addition to releasing unwanted chemicals into your product, bottles can contaminate hemp and cannabis in other unexpected ways as well. For example, bottles easily collect dust over time, which can contaminate products with a combination of bacteria and allergens it contains.

How to Prevent Packaging Contamination

1. Know your supplier. You invest significant time and resources into crafting a clean and safe formula. Packaging selection should be no different. Low-cost goods from China might entice you. But if you’re going to go that route, make sure to know exactly what materials the bottle contains and do your due diligence on the company first.
2. Reduce transit time: Optimize your supply chain so that it’s tight and efficient. And wherever possible, try to store your products in climate-controlled shipping containers that maintain moderate temperatures and prevent direct sunlight from seeping in.
3. Invest in a complete cleaning system. You can easily prevent the dusty bunny crisis by investing in a bottle cleaning system that removes dust along with other unknown particles. During the process, these cleaning machines utilize ionized air to neutralize the static charge that attracts dust to the bottle’s surface and the inside as well.

2. Single-Use Gloves

This year, a pesticide-free company had to recall its cannabis strains after laboratory tests confirmed o-Phenylphenol contamination. After further investigation, Freya Farms discovered the unfortunate source–FDA-compliant food-grade gloves used to process their products. So how does something like that happen?

According to the National Cannabis Industry Association, once the gloves received initial FDA approval, they were not subject to ongoing testing to ensure the consistency of quality over time. That gives glove manufacturers opportunities to source cheaper raw materials, reduce durability, and introduce harmful contaminants that end up transferring to the products.

How to Prevent Glove Contamination

Unfortunately, if you can’t trust FDA-approved food-grade gloves, you can’t trust anything. Scientific studies have shown many single-use gloves contain harmful toxins and impurities. That means you have to take matters into your own hands and consider where your gloves have been before you buy.

In an interview with National Cannabis Industry Association, Eagle Protect CEO Steve Ardagh said it’s vital to source high-quality gloves that a reputable third-party laboratory has tested. If you can’t verify the safety of the gloves you are buying, consider looking elsewhere. Ultimately, deliberate, mindful sourcing is critical.

3. The Extraction Method

In a recent interview, AC Braddock of Eden Labs told ACS that CO2 is one of the best methods to produce clean, medical-grade products because of its anti-bacterial qualities. In fact, even if the extraction machine had bacteria before putting the flower in it, the CO2 will clean it out and prevent cross-contamination. But that’s not the case with every extraction method.

According to AC, when you work with hydrocarbons, you risk contamination because some bacteria feed on these organic chemical compounds. So, if you don’t remove the hydrocarbons from the extract and leave the solution in a jar on the counter at room temperature, the bacteria can multiply.

Even solvent-less extraction can present contamination risks because water is still a solvent and can be easily corrupted. Moreover, the extraction process does not remove pre-existing contaminants in the process. That means if the plant contained toxins before extraction, those same substances would corrupt the processed oil as well.

How to Prevent Contamination During Extraction

According to AC, processors must purge the solvents from the material thoroughly when it comes to hydrocarbon extraction.

“People like hydrocarbon extraction because they say it’s a rapid method. But the purging process is very time-consuming and required if you want a clean product. Processors who take this extra step to prevent contamination are doing the right thing, but those who cut corners put people at risk,” said AC.

When it comes to solvent-less extraction, it’s vital to understand the risks and source 100% clean crops, to begin with. Even if a grower provides a Certificate of Analysis (COA) proving the purity of the flower, processors should double-check by sending samples to a verified third-party laboratory first.

4. The Air or Wind

A strong gust of wind can become your worst nemesis. For example, did you know male cannabis pollen grains can travel up to 30 miles from a nearby farm to corrupt your virgin female plants? Yikes. And with hemp acreage growing exponentially every year, your farm may be at significant risk for cross-pollination.

In addition to pollen grains, the wind can carry any number of corrupting substances. Following the California wildfires last year, a toxic byproduct called polycyclic aromatic hydrocarbons (PAHs) polluted the air. While no one knows the extent of damage these fires have caused, historical research proves that excessive PAH content in CBD oils can be directly attributed to nearby forest fires.

Pesticides can also travel by air from your neighbor’s farm right to your doorstep. What’s worse? Your neighbor could be growing a crop like cotton, which requires significantly more pesticides than you want in your plants.

How to Prevent Toxic Drifts

Unfortunately, you can’t beat the wind. But you can avoid toxic drifts by growing hemp and cannabis indoors, where you have much greater control of the environmental conditions.

If indoor cultivation is out of the question, it’s best to figure out who your potential neighbors are, what they grow, and what type of pesticides they may use before you buy a plot.

If it’s too late for that, your best options may be to build a protected grow house or consider moving your operation to a different location. Vegetative buffers could also prevent cross-pollination by making a barrier.

The Bottom Line

The slightly gloomy reality is that no matter how careful you are, your plant or product can become corrupted at nearly every stage of the supply chain through no fault of your own. That’s a tough pill to swallow, but fortunately, you can prevent most unexpected causes of contamination through careful planning and consistent, full-panel laboratory testing. The earlier you can detect a problem, the better your chances at avoiding potential recalls and guaranteeing a quality end-product.