The cannabis industry has spent the last decade obsessing over potency. THC percentages dominate menus, packaging, and marketing conversations, often treated as the primary indicator of quality. But as the market matures and competition tightens, potency alone no longer tells the full story.
Increasingly, the real differentiator between a premium product and a liability is something far less visible: impurities.
What are Impurities in Cannabis Products?
Impurities are the unwanted substances that find their way into cannabis products somewhere between cultivation and the consumer. They’re rarely intentional, often misunderstood, and frequently underestimated. Yet they carry real consequences—failed compliance tests, recalls, consumer distrust, and long-term brand damage. In an industry still working to establish legitimacy, impurity control isn’t just a technical issue. It’s a credibility issue.
I’ve been fortunate enough to spend much of my career working hands-on in cannabis extraction and product development, learning from trial and error, enduring hard failures, and constantly challenging the norms. One thing that has become clear over time is that impurity issues rarely arise from a single mistake. They’re usually the result of small gaps in systems that compound as operations scale. Understanding where those gaps tend to appear is the first step toward closing them.
What Impurities Mean
From a regulatory standpoint, impurities are fairly well defined: microbial contamination, mycotoxins, heavy metals, pesticide residues, residual solvents, foreign material, and unintended chemical byproducts. These are the categories labs test for, and regulators enforce.
From an operational standpoint, impurities are better viewed as indicators. They point to weaknesses in sourcing, environment, process control, or equipment design. A failed test is rarely random—it’s feedback. The challenge is learning how to listen before that feedback becomes expensive.
Passing a compliance test is necessary, but it isn’t the same thing as having a robust quality system. Results that consistently land just under allowable limits may technically pass, but they leave very little margin for change.
How Impurities Happen
Cultivation Sets the Foundation
Most impurity risk begins long before extraction or manufacturing. Cannabis is a bioaccumulator, meaning it readily absorbs compounds from its environment. Heavy metals can enter plants through soil, water, nutrients, or even cultivation infrastructure. Indoor cultivation reduces some risks, but it doesn’t eliminate them—water quality, nutrient sourcing, and equipment materials all still matter.
Pesticide residues are another common challenge. Even approved products can create issues if application timing, rates, or environmental conditions aren’t tightly controlled. In some cases, contamination doesn’t come directly from the grower at all, but from upstream suppliers like clone nurseries, soil contamination, or shared equipment.
Microbial contamination is often the most complex to manage. Mold isn’t just a sanitation issue—it’s a systems issue. Genetics, airflow, humidity control, canopy management, and drying conditions all play a role. Once mold is present, mycotoxins become the larger concern, as they can persist even when visible growth is no longer detectable.
If inconsistencies exist at the cultivation level, downstream teams are forced into mitigation instead of optimization.
Post-Harvest: Where Control Really Matters
Drying and curing are deceptively critical stages. Small changes in humidity or airflow can dramatically affect microbial risk, terpene retention, and overall stability. Too much moisture invites contamination; too little can accelerate degradation and create fragile material prone to oxidation and particulate shedding.
Storage conditions continue that story. Exposure to heat, light, and oxygen drives predictable chemical changes. THC degradation into CBN is a natural process, but it still affects consumer experience and product consistency. Even when these changes don’t trigger regulatory failures, they impact trust.
Foreign material contamination—hair, fibers, plastics—is often overlooked because it doesn’t always show up on lab results. These issues are almost always preventable with thoughtful handling procedures and facility discipline.
Extraction and Manufacturing Introduce New Variables
Extraction adds complexity. Solvents, temperature, and mechanical processing all increase the number of ways impurities can be introduced or formed. Residual solvents tend to get the most attention, but they’re often a symptom of broader process inconsistency—equipment wear, purge variability, or insufficient validation.
Manufacturing introduces additional risks. Heat and time can alter molecules. Reactive surfaces can catalyze unwanted reactions. Formulations that work at a small scale don’t always behave the same way when production volumes increase. These aren’t theoretical concerns; they’re realities operators encounter as they scale.
Vape products, in particular, require careful formulation and discipline. When something is designed to be inhaled, every ingredient should earn its place. Stability testing and material compatibility go a long way toward avoiding downstream problems.
Equipment design also matters. Systems that can’t be easily and thoroughly cleaned will eventually become contamination sources. Preventive maintenance and cleanability should be treated as quality controls, not operational inconveniences.
Testing is Informative, Not Protective
Laboratory testing plays an essential role, but it’s only one piece of the puzzle. Sampling variability and batch heterogeneity mean that test results are snapshots, not guarantees. Relying on final testing alone puts teams in a reactive position.
What’s more effective is trend analysis; watching data over time across cultivars, rooms, processes, and inputs. Impurity issues almost always show patterns before they become failures.
Prevention Over Correction
Remediation technologies can be useful tools, but they’re not a substitute for good process design. They come with tradeoffs—cost, potential quality impact, and consumer perception. The strongest operations focus on preventing impurities rather than fixing them later.
That means qualifying suppliers, testing inputs, validating processes, maintaining equipment, and designing facilities that support clean production. None of this is flashy, but it’s what enables consistency at scale.
Where the Industry Is Headed
As cannabis continues to mature, the conversation around quality is shifting. Consumers are more informed. Regulators are more experienced. Brands that consistently deliver clean, stable products will earn trust over time.
Impurity control isn’t about perfection—it’s about discipline, humility, and continuous improvement. It’s about respecting the plant, the process, and the people who consume the products we make. That’s how the industry moves forward, and how it earns the credibility it’s been working toward.
About the Author
Dylan Thiel is the co-founder and Chief Technology Officer of Dabstract, where he oversees operations, brand expansion, and product innovation across the brand. With over 10 years in cannabis extraction and product development, Dylan helped pioneer Dabstract’s signature Live Resin HTE and other early formulations. He brings a hands-on perspective and technical expertise to his work, sharing insights from years of experience in the cannabis industry.”
