Pesticide Residue Testing in Cannabis

Written by Nicholas Demski
  • How state-to-state collaboration could ensure the quality and health outcomes of cannabis consumers.

Imagine you’re growing up in a community where everyone knows everyone else by first name. You wave to people as you slowly drive down the main street. The postal worker sees you at the grocery store and gives you a letter he forgot to deliver this morning. On the way out of the store you ask the cashier how Frank and Roberto are–her two pugs.

As you go home, you pass by the three other houses on your country road. One of the families is aware of a cow that fell into one of their wells a week earlier. The water isn’t safe, but they don’t tell you or the other neighbors, and in a week, your child is sick.

How would you feel about the family who didn’t share valuable information with you? You had trusted that should there be a problem, especially a health hazardous problem, it would be known.

A similar situation is occurring in pesticide residue testing for cannabis.

The Schedule I status of Cannabis makes regulating testing incredibly difficult, with no uniform set of regulations or best–practices laid out. [1] As a result, there have been differences between states on what to test for and how to test for it.

Some states provide lists of pesticides that can be used and should be tested for when dealing with cannabis. This makes it easier for labs to narrow down their search and more accurately identify pesticide residue in cannabis products.

Figure 1 Is your cannabis pesticide-free?

However, some states don’t provide any pesticide list at all, and the testing labs there can be threatened with needing to screen for hundreds of possible pesticides to provide accurate results. Given the time, effort, and money that goes into testing for so many different chemicals, labs are strained and may not provide the most accurate or comprehensive results. Which brings us back to the cow in the well.  Should a lab not test for a specific pesticide that a grower used, or that found its way onto the flowers, whether a list is part of the regulatory code or not, the presence of this pesticide, like the cow, goes unmentioned and unnoticed.  The repercussions of ingesting this contaminated cannabis could be bleak.

A 2013 study in the Journal of Toxicology showed that smoking cannabis with pesticides on it does little to stop the transfer of pesticides into the bloodstream. [2] They reported seeing pesticide recovery levels at nearly 70% in handheld glass pipes. While filters and water pipes showed lower indications of pesticide recovery in the bloodstream, the goal should always be to cultivate cannabis using approved pest reduction strategies, and to ensure proper lab testing is to ensure that the product is safe for trusting consumers that expect it to be.

Are pesticides in your cannabis something you worry about? Let us know in the comments!


  1. “Cannabis Pesticide Testing Updates.” Accessed June 27, 2018.
  2. “Determindation of Pesticide Residues in Cannabis Smoke.” Accessed June 27, 2018.

About the author

Nicholas Demski

Nicholas Demski's latest venture is He's a poet, author, cannabis writer, and budding entrepreneur. You can follow his travels with his daughter on YouTube, Facebook, and Instagram @TheSingleDadNoma

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