Smoke and Mirrors: 10 Ways The Cannabis Industry Can Manipulate THC Percentages

In a prior blog, I examined how cannabis testing is performed, and how important precision in processes and audits are vital to maintaining the integrity of test results. We’ve also discussed how important off-the-shelf testing is to ensure that testing results are accurate and reflect what consumers are able to buy. 

The reason these controls are so important is due to the many opportunities that corrupt cannabis laboratories have to change results of cannabis tests. 

Let’s take a look at some ways they can do that!

1. Sampling Cheats (Laboratory / Producer)

  • Appropriate sampling procedures are designed to ensure that the sample taken from a cannabis batch is representative of that batch. The reason that I’m listing this first and foremost is – if the sampling is done incorrectly, the results will suffer at best and be rendered meaningless at worst.

    First and foremost, batch sampling can weaken the chain of custody for cannabis samplers. In most cases, the farms or producers are in control of the sample that is presented for sampling, and they can present the incorrect material for testing. This means that there is no way to guarantee that the product which is being presented for sampling is the one similar to what ends up on the shelf.

    In some states, sampling regulations leave a lot to be desired. In Oregon, batches are allowed to be kiefed. ‘Kief’ refers to the trichomes that fall off of cannabis when it is disturbed – this fine powder contains a high percentage of THC. ‘Kiefing the batch’ refers to the process of adding kief back into the batch of flower before testing.

    But farmers and producers aren’t the only ones that can manipulate samples – labs can too. 

    There are different ways lab-side sampling issues happen.  A sampler could be handed a bribe and a pre-prepared sample. Farmers could leave the samplers with some kief and some time.  There have been accusations that farms can request a particular sampler known to sample in a way that is good for the farm. 

    These are all methods that have happened in reality – among several other ways. But the bottom line is: If a sample isn’t representative of the product, the test results are meaningless, no matter how we got there.

2. “Mathemagic” (Laboratory) 

  • Using Moisture % as a way to alter the number. Moisture content or moisture percentage calculations present an opportunity for THC percentage numbers to be ‘tuned.’ The impact of this little mathemagical trick is slight, but it could be enough to make flower just a bit more viable in the current (cutthroat) marketplace. 

  • Using a different calculation for loss on drying. There are two possible ways to calculate loss on drying:

    • (moisture loss) / (wet or starting weight)

    • (moisture loss) / (dry or ending weight)

These formulas render slightly different results, and present another way that labs could make a subtle change in the THC percentage numbers. Labs aren’t always clear or consistent on which methods they use, and different methods mean you aren’t always comparing apples to apples. 

3. Spike The Sample (Laboratory / Producer) 

  • There are a lot of ways to spike a sample of cannabis. This behavior ranges from kiefing the batch (which is legal in some places, like Oregon) to spiking the sample with distillate. 

    Luckily for regulators, each version of spiking a sample is detectable.

    Using distillate used to be a popular way of increasing the potency of flower until it became easy to detect by looking at the ratio of delta-9 THC to THCA. The use of THCA isolates is similarly detectable.

    Spiking samples to get higher potency values is a common and fast way to increase potency for selected results, especially if the state lacks effective lab audits that include off-the-shelf testing.

4. Using a Reference Standard Known to Give High Results (Laboratory) 

5. Calibration ‘Tricks’ (Laboratory) 

  • Calibrating the lab equipment to accurately reflect results is an important step in creating accurate lab results. An intentional miscalibration of the machine would skew all of the results – and some states have regulations that standardize parts of the calibration.

    Most calibration ‘tricks’ could be caught during a thorough audit by regulators. There is no way to address all of the possible tricks that could be used without a comprehensive audit of the entire process, including preparation of the reference standard for calibration. States require PT tests to confirm calibration of results, but oftentimes labs know when they are being tested or are required to ‘self-audit’ their results and don’t have the results double-checked. This leaves a lot of room for potential cheating. 

    This is another method that could elevate the results en masse.

6. Incorrectly Entering Sample Weight for Calculations (Laboratory)

  • A simple way to skew THC percentage is to simply enter an overall lower mass for the sample.  While the equipment used to record the mass must be calibrated daily, there is nothing to prevent this, and very few labs have the equipment that interfaces this information with their lab information system, much less regulatory systems. Recording a mass around 10% lower than actual will yield roughly 10% inflation for potency.

    Say you have a 1.1 gram sample that has 1000 mg of THCA in it.  1000 mg THCA / 11000 mg sample weight = .09091 or 9.01%.  If I change the sample weight to 1 gram instead, 1000 mg THCA / 10000 mg sample weight = .1 or 10%.  

Dry Labbing (Laboratory) 

Lab Shopping (Farmer / Producer)

  • Many in the industry will tell tales of farmers and producers shopping product from lab to lab, seeking the sorts of THC percentages that will make their flower or product more marketable. 

9. Intentionally Overstating THC Percentage Than What is Labeled For Advertising (Retailer)

10. Last, But Not Least: The State Doesn’t Stop Them (All Of Them – Farmer / Producer / Laboratory / Retailer)

When regulators are incapable or unwilling to address behavior by bad actors, the impact to the market is severe. The THC percentages can spiral out of control. Unchecked manipulation of the THC percentage rendering the number meaningless and decreasing consumer confidence in the product and testing process.

The nascent cannabis industry has demonstrated its importance to consumers and its relevance as a market. One of the arguments used to legalize cannabis was to make cannabis safe for people to consume through full testing. Unfortunately, that is a promise that the industry and its regulators have still failed to completely deliver on. It is vital that regulators set up a system of checks and balances that includes off the shelf testing and a reference laboratory to ensure that the product is safe and labels are accurate.