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Lab testing - what are you testing for?

What are you testing for when you run a lab test? THC? CBD? Other Cannabinoids? Terpenes? Bacteria? Mould and Fungi? Pesticides? Herbicides? etc…


@cmtlabs - I would be interested to hear about your testing processes and protocols. What do you find are the most common test requests or requirements?


Hi, Nathan!

These are the tests we offer in order of frequency requested:

  • potency - THC, THCa, CBD, CBDa, CBN (we also do homogeneity on edibles by doing 3 potency tests)
  • microbial - total yeast and mold, E.coli, and salmonella
  • residual solvents - n-butane, isobutane, benzene, toluene, xylene, heptane, hexane
  • terpenes - limonene, β-myrcene, linalool, α & β pinene, β-caryophyllene, α-humulene, terpinolene, camphene, ocimene
  • shelf stability - pH and water activity

We are on the pesticide working group, and pesticide testing will begin in Colorado by the end of summer. We have all of the equipment to do that already at two of our three locations.

Colorado requires that all licensed recreational businesses test for potency on all products, microbial for flower/edibles, residual solvent for extracts, and shelf stability for edibles. They mandate all medical businesses test for potency of flower only.

Let us know if you have any more questions, and have a great day!


@cmt do you have a list of the pesticides you will start testing for once the Colorado pesticide testing requirements are in place?



We’re waiting to see what the state required to be tested, and we will test for everything that they require.

You can reference this list of currently banned pesticides in Colorado here.

There’s also an approved list here.


Thanks for the links. It’s interesting that on the list of approved pesticides, half the products with Neem oil are allowed for commercial use, and the other half aren’t. I couldn’t see any difference in the other active ingredients to explain that. This conversation about Neem oil here made me think to look for that:


I had seen that conversation. I know that there are no current rules against neem oil being used, so it would be about another ingredient in the product.

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That makes sense. Too bad they don’t list the inactive ingredients as well.


CMT, thanks for being so responsive. I’m curious – we decided to run a test and I wonder if you’ve seen this or done this yourselves: we’ve heard that pyrethrin bombs are not systemic to the plant. We wanted to test this to see just how accurate this thinking is.

To test this we took a single purple diesel that was about a week away from finishing, cleared the rest of the room then set off two pyrethrin bombs. We’ve subsequently harvested the plant, given it our standard prophylactic H2O2 bath and dried and cured the plant. We intend to run a full assay on it in the next few days to see if we’ve eliminated any trace of pyrethrins.

Have you seen or heard of anyone else doing this ? Have you seen or heard results of such a test? Do you have more information about pyrethrins and systemic uptake by cannabis plants?


We haven’t done any research on that ourselves.

I’d love to hear more if you keep notes on your process, though!


Has anyone done a H2O2 comparison test - testing cannabinoid and terpene content etc on the same product that has been cleaned with H2O2 and not? What are the losses? Are they noticeable?


We’ve had one dispensary reach out to us to do this research with them, but we’re still waiting to get that started.

We’re ready! We’d love to help in this research, and as soon as someone sends the samples, we’ll start looking into it.

Our lab director doesn’t think there will be any cannabinoid loss, but she says there is likely terpene loss.


@cmtlabs I’m dealing with a problem where I believe the lab that’s performing all our mandatory lab testing (yes… the one), wrong.

Multiple, drastic inconsistencies, flawed math, wrong names, etc. It’s been going on for about three months now.

Is there some in-house THC tester that I can lease / buy to give me accurate-enough results to show that our lab is full of BS?

Also, what can I do to validate their results / challenge them?

Thank you!

.: CG


I’m sorry to hear that.

In what state are you located?

You’d need an HPLC to test cannabinoids accurately, which are priced pretty steeply, and you’d also need an analyst on site who knows how to read the peaks, prepare the samples, calibrate, add an internal standard, and more. It’s a pretty complicated process.

We actually used to be Colorado Mobile Testing (which is from where the CMT comes), and we used to travel to grows to do tests on-site, but the laws here no longer allow for that.

We’re looking in setting up in-house labs for businesses in the future, though, so that people can do extra testing themselves for the reasons you mentioned, as well as for their own research and QC.


@cmtlabs - @caribbeangreen is in Puerto Rico, so I imagine that there’s not a lot of labs setup there yet.


That makes complete sense. @caribbeangreen I love Vieques!

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Yep, there’s only the 1. And they’ve even told me that “they’re figuring it out as they go”. Not too reassuring…


Sounds like a good opportunity for someone to setup a new lab. Puerto Rico trip @cmtlabs?


If you’d like to email us for more about this, @caribbeangreen, please email us: info (at)!

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We’d definitely be interested to work with you. Please contact me directly and we can figure out if this is possible!


Oliver Starr, CEO