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I like this article. Any thoughts to add or feedback?


Looks like a thorough overview with some good recommendations. Glad to see that there is research being done on this issue!


Some great information! To me that is one of the most important components of the process. We have to ensure that what we are providing to our customers is not going to cause them any issues other than a case of the munchies - as it is such a medicinal plant the grower should hold themselves accountable to the hippocratic oath and ensure that they “do no harm”.


Awesome article! lots of good info, thank you for sharing!!


Thanks for sharing. Great article.

Our lab is state-certified in Colorado to do total yeast and mold testing, as well as screen for E.coli and salmonella, so please let us know if you have any questions about these tests or this article.

We’d love to discuss. :slight_smile:


Well said Nathan! I’m very passionate about discovering how to create the healthiest and most holistic medicine.

I’d like to share this, it’s a quote from the American Association of Nure Practitioners. It is astoundingly, exactly how I feel and what I believe to be true when it comes to practicing and advocating for the cannabis community.

As Nurse Practitioners, it is our responsibility to follow:

" The patient-centered nature of the NP role which requires a career-long commitment to meet the evolving needs of society and advances in healthcare science. NPs are responsible to the public and adaptable to changes in healthcare. As leaders in healthcare, NPs combine the roles of provider, mentor, educator, researcher, and administrator. NPs take responsibility for continued professional development, involvement in professional organizations, and participation in health policy activities at the local, state, national and international levels” (American Association of Nurse Practitioners, 2015).


We spend over $4,000/mo testing flower brought in by our associate farmers and we have found that the results can vary even among the different labs in our area. Also, when dealing with fresh flower you may get a passing test on Micro but after processing the flower into prerolls and packaging them a new test would most likely fail due to bacteria growing. We are now working on a process that will guarantee clean, all zero results on Micro. (If you use Pesticides then it is garbage).


@medi-cone what sort of variation are you seeing between labs? Is it just differences in levels detected or are some labs passing test while others are detecting contaminants? I’d be interested in hearing about your new process once you get it up and running.


Some items get passing micro at one lab and failing at another, we’ve even tested two buds from the same bag at the same lab and get different results. When we ask they say that there can be variations between buds. The point is, testing is probably stricter than most foods we eat and as the California law goes into effect next January there is going to be ALOT of discussion regarding this topic. Yes, we will let you know when we are secure in our ‘all zeros’ test results.


@medi-cone do you test for neem-oil?

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Neem passes but isn’t effective for long term prevention plus it clogs the stomata…
You’ll need to use it in intervals with another safe product.


How often are people failing your tests? We’re in CA and use only organic techniques. As a result of our use of beneficial biologicals we’ve been told by SC Labs that an H2O2 wash is recommended prior to drying and curing. We’ve instituted this process at scale across our operations with good results, but wonder what others that use various foliar biological treatments are doing to ensure a clean test?


Not many people fail, statistically, but it does happen sometimes. Businesses are able to get “process validated”, and then they don’t have to test again for a full year, when that expires.

When people fail in Colorado, they must immediately either a) destroy their product, or b) blast their product into a concentrate.

H2O2 is on the approved pesticide list in Colorado (see here).

It does seem to lower terpene levels, though, resulting in a lower quality product. We haven’t done any specific research on that topic, but we plan to do so in the future.


Because we use natural biologicals like OG Biowar as part of our foliar feeding and top watering regimen, we KNOW are cannabis would fail the microbiological tests. At least in CA, the plate count tests are incapable of discriminating between beneficial and harmful bacteria.

As a result we’ve instituted an H2O2 wash as part of our harvesting process. It adds time and an extra step in our finishing but we’ve found it produces the cleanest, safest medicine.

While we have heard that H2O2 can reduce terpene concentrations, our Purple Diesel tested at 3.36% total terpenes by Steep Hill and our Tahoe OG scored 2.33% total terpenes from SC with a total THC of 25.51 and a total cannabinoid concentration of 26.5%.

We do see VERY substantial variation among labs and this is a subject of concern and frequent discussion in my grower community.


Outstanding paper!

“Cannabis should be tested for four species of Aspergillus: A. flavus, A. fumigatus, A. niger, and A. terreus. Together these species are responsible for the vast majority of cases of invasive pulmonary aspergillosis, and they are the only pathogens that represent a clear and certain danger on Cannabis.”

Aspergillus, scares the hell out of me! Afotoxin show up in WHO reports for bad things the U.S. does in exports of grain. Tolerance in grain production is almost zero. We export grain that does not meet the standard for domestic uses, to Asia and Africa. Ground black pepper has a strange exemption from afotoxin regulations yet it is the number one source in the U.S.


I’ve been experiencing similar issues in a similar grow. Would you mind sharing how you H2O2 wash? We’ve sprayed buds before, and they have turned brown and lost terpenoids noticeably…


Hi, Cody - our process is simple, upon harvest and before the plants are removed from the flowering room we take the entire plant and dip the entire thing in a large tub containing a 5% solution of H2O2 in filtered water. Plants are submerged, soaked for about 5 minutes, dipped in the clear water and hung to dry. We hang whole plants until ready to buck, then we dry trim before a 21 day cure.

Using this process we’ve had medicine test as high as 26.2% Total THC (growing organic in soil) for our Tahoe OG and 3.36% total terpenes for our Purple Diesel.

Plants in the video are still dripping from the rinse dip.


I can’t get the video to play. I will try from a desk top tomorrow.

We used an 2% H2O2 solution on cuts and produce with good results. No foliage or flower damage. We have even pulused peoney with .25 to 2% solutions. Over .5% on H2O2 in a pulse with 5% sugar for ten minutes we see floral discoloration and lose of shelf life. Water needs to be 68 to 70 degrees for a pulse.

Dipping I don’t have a clue.

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Not that this really has any value to debates around our product’s microbiological safety and cannabis consumption…

But here is our MSDS… it’s safety related?? :thinking:
URB MSDS.pdf (135.7 KB)


For some reason dropbox links don’t embed well on this platform. Here’s the download link without an embed so you should be able to download it locally and play it.