Consumers are increasingly seeking out highly concentrated forms of cannabis including tincture oils and concentrates like shatter, wax, budder, and crumble. Many of these concentrates are produced using chemical solvents. Here we offer an overview of the role chemical solvents play in the cannabis industry, their potential health risks, and how consumers can avoid exposure.

When Are Solvents Used?

Solvents are used during the extraction process to separate cannabinoid and terpene compounds from cannabis plant matter. The result is a highly concentrated oily or resinous substance known as a cannabis concentrate.

Cannabis concentrates can come in many forms with varying consistencies, textures, and potencies. The differences largely depend on the extraction method used to produce each concentrate.

Although solventless extraction methods have been developed, solvent-based methods are still the most widely used. That’s because solvent-based methods allow producers to efficiently generate large volumes of concentrated extracts. The big three solvents most frequently used in the cannabis industry are ethanol, carbon dioxide, and hydrocarbon solvents like butane and propane.

What Are the Health Risks?

The solvents used in the cannabis industry tend to be less toxic than harmful Class I solvents such as benzene. For example, propane and butane are not very toxic unless users are exposed to high levels of these substances. However, being exposed to lower levels of chemical solvents may still pose a health risk, especially in the case of ongoing, chronic exposure.

One 2019 study described a case of acute hypoxic respiratory failure resulting from the frequent use of butane hash oil (BHO), a type of cannabis concentrate produced using butane. The authors acknowledged that repeated inhalation of butane likely contributed to the patient’s symptoms. However, the patient confirmed that the BHO was purchased illegally.

Cannabis Testing Minimizes the Risk

Producers of legal cannabis concentrates are careful to remove the far majority of solvents used during extraction in a process called purging. But this highlights an important fact in terms of cannabis safety. When cannabis products are well regulated, the risk posed by potential contaminants like residual solvents is greatly reduced.

Comprehensive cannabis testing that includes analysis for residual solvents and processing chemicals ensures that producers use only approved, low toxicity solvents and properly purge their concentrates to minimize the amount of residual chemicals left in the final product.


Chemical solvents are used in the production process of many cannabis concentrates. While solvents can potentially pose a health risk, users can curb their chances of exposure by purchasing cannabis concentrates from licensed vendors

Are you looking for full-service cannabis testing? Encore Labs offers a comprehensive menu of testing services to ensure your cannabis business meets the regulatory guidelines in the state of California.