Testing Woe’s

Good evening everyone,

First off I’d like to extend my thanks and express my gratitude. This forum is absolute gold. I’m a new member, and am fascinated by the amount of information given coupled with the expertise.

I work in the MMJ industry in AZ. The labs out here have been unregulated for the better part of 8 years. Labs have created their own in-house methodologies and validation methods, this has created notable variances between competing companies. Our company struggles with finished good potency. Our distillate supplier provides CoA’s with all purchases with potency over 91 every. single. time. We recently made a change to which lab we test at. Please keep in mind that we made this change for the better, the new lab is very reputable and is on track to become the first licensed lab in AZ. Our distillate potency has dropped 10% in some cases. The lab explains it’s an accurate result and previous ones may have been manually inflated. That realization is a tough pill to swallow considering price point is directly associated with potency. The lab has preformed an audit and passed with flying colors. How could a supplier or producer validate the accuracy of a testing facility’s methods and validation process? Thanks for any and all help!

In-house analytics. You are paying for a service, if you can show that you aren’t getting the service you can withhold payments, break contracts, etc. This happens all the time in food and beverage. If the 3rd party lab messes up compared to the in house number enough times, they lose the business.

It can be daunting if you don’t know where to start, but if that’s the case you are definitely in the right place and it’s really not as expensive as the labs would have you think.

My 2¢ Cheers!


Great point. Unfortunately we do not have the capabilities to build out an in-house analytics lab to compare results. Maybe hire an analytical supervisor who can preform 3rd party audits ?

Yes, find even a part-time consultant that knows the analytical side and they can keep a bad lab in check. But even good labs will screw up occasionally.

Definitely don’t just take the labs word for it. There are so many bad or flat out fraudulent cannabis testing labs.

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I appreciate your prompt response! It’s been of massive assistance.

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It might get expensive but send 3 samples to three labs, three different times under different accounts. Dont tell them anything besides it being a high potency concentrate. See which lab comes out with consistent results for all three 3 samples
FYI most labs are 10% off at most. So if u have 91% thc distillate. That could come back as 82-100% and still be a valid test…
If companies are coming back with inconistent tests over 5% off i would drop em.
I would do this quarter or biannually to test out any " good labs" in the area but that also depends on ur production level and cost/benefit


^ this is definitely a good way to go. The problem becomes how often do you check. But I highly recommend doing what @Thetetraguy said!

We will definitely give this a shot! I’ll let you guys know how this ended up!

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If your still stuck between two labs, take a very accurate scale and dilute your distillate to three different ratios. Record the dilution rates, then send to your two labs. See who gets closest to ur numbers

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Sent out 3 tests same batch under various sample names to 3 different labs! We typically experience a 3 day turn around on potency. I’d like to thank you guys again for the advice. Greatly appreciated.

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I’ve been an analytical chemist for 5 years, three of them in the cannabis industry. My experience was actually at an internal quality control lab, not a third party lab - so I’ve personally had experience with double checking a third party lab.

While yes, you could get your own set up so that you can double check the lab, it’s cumbersome and not easy. I don’t care what anyone says - it’s not easy. Period. And in reality, if you make your own method and figure out how to do your own testing, you’ll STILL vary from the other lab. So it’s not worth it.

I think your best bet is to go to the lab and ask them if you can review their “Validation Report”. Every verified lab, especially if they are ISO 17025 certified, will have a validation report for every single method they use - potency, pesticides, heavy metals… etc.

If they passed their recent audit, then they definitely have a validation report. With this, number one, you just want to know that they validated their methods. Number two, you can see what kind of statistical variation they have sample-to-sample. Number three, you can see what experiments they ran in order to validate. This information can give you a lot of insight into what’s going on over there. Honestly, if you don’t know what you’re looking at or how to interpret it, just record it and post it here and I’ll help you.

In toxicology, the governing body tells the lab what experiments they are required to run. One of the most important ones is called an “intra-lab” study where multiple labs swap unknown samples and observe how closely their results fall. Cannabis does not have a governing body - well I guess ISO 17025 is required in most states, but not all and I’m not sure about AZ. In any event, it’s not nearly as well put together as the medical industry. Long story short, I’ve only met one lab in 5 years that was willing to do an intra-lab study. ISO does not require this. I’d find out if your lab did one, if they did that can lend quite a bit of credibility.

Honestly, there are a million things you could do to verify the lab’s legitimacy and I don’t think you have to spend any money to figure it out.

Can you post the name of the lab? I can look them up for you too and see if I find anything. You just need someone who knows what they are looking for, that’s all


while I agree with this, it’s still not possible to know who’s right because at the end of the day it’s a blind sample to everyone.

Why not buy a standard and then spike a matrix void of cannabinoids, like olive oil or something, and then have the lab test it? Then you know for sure what the potency is and who’s giving out inflated/inaccurate results.

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I would implement in house analytics as soon as feasible for your situation. I disagree that it’s hard and can actually be inexpensive if you are careful. The standards should absolutely be your largest expense. What your actual goal is and the number of standards you choose to purchase depend on your situation and market. Alternatively, I feel like the Nevada market is much dependable and reputable if you are not afraid to cross the border.

Potency testing in theory isn’t hard, but I mean, if you’re tight on a budget and you’ve never done it before, it’s not super easy to figure out on your own especially if you need answers fast. I don’t know, maybe I’m just a slow learner

No offense intended. I just take my cues from the food industry and they would never solely rely on 3rd party testing. I bet 50% of food testing fails 3rd party and is forced to be run again by clients who know what the results should be. It’s amazing to watch.

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No, none taken at all - I welcome all opinions.

And I completely agree with you - in house analytics gives you a lot of power. Otherwise you’re blindly relying on an unregulated industry. All your eggs in one basket, it’s just not responsible as a business owner.

I just think before OP gets there, because it could take a while, it may be faster and easier to just spike a blank matrix and force the lab to basically participate in a proficiency study.


You are right not everyone can jump right in, but I try to point them that way my earliest convenience.



And this is why I love this forum. I learned a lot today. Thanks guys.


It’s not easy to implement in house analytics but it’s more than possible. the people down at SRI have a decent GC unit at an awesome price… The best part is they’re units come with the
Methods already developed… They’ll hold your hand through the whole ordeal of calibration too… I’m surprised @srihugh1 hasn’t chimed in yet.
You can get cheaper (and better but honestly most people won’t have good enough analytical chemistry technique to make a fancy device worth it) used units but they won’t come with the great customer service and support of SRI


Also just because your newer lab has lower results doesn’t mean they’re more accurate lol