The Challenges of Measuring Heavy Metal Contaminants in Cannabis Vaping Aerosols

I know a lot of this may be stuff people are already familiar with here, but still a decent little paper


This is a facinating and important subject matter.
It deserves considerable attention at a number of levels.

  1. composition of cannabinoid oils (including natural
    heavy metals from soil contaminating oil preparations)

  2. contamination of oils by pen and cartrige components
    including heating element vaporization

  3. physical nature of the oil/air aerosol as it is formed

  4. ultimate contamination of the aerosol itself by oil residuals and vape-pen components.

  5. is there such a phenomenon as non-aerosol cannabinoid vapor? answ. no. (of physiological significance).

  1. transport of aerosols to lower lung, equilibration with water vapor in lung at 37C, rain out, dissolution into aveoli detergent, and transport to capillary bed. No one at this time knows whether cannabinoids are transported in blood as micelles or solutes…and of course the BBB aspect.
  2. we only know the thc/ cannabinoid reach central receptors in about 15-30 seconds after inhalation.

A lot of science.


So how cost prohibitive is this type of testing? Matt at divine tribe was the first I saw discuss it publicly(a while back) and he was saying it was thousands+ to have aerosol tests done

This is a really interesting read. Thanks for sharing it!

This might sound dumb, but I hadn’t even considered the acidity of distillate being enough to dissolve metals into it.

I wonder how many brands have oil that tests clean, but has a bunch of heavy metals when vaped, either from leeching into the oil in the tank or from being heated.

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I haven’t read the post yet but isn’t it as simple as sticking a cannula off the side of a cart condom, pulling a big draw on it, and shooting that sample through GCMS? Doesn’t seem like it would be very hard to get at least a qualitative result with a standard headspace method

You should probably do this, it’s an interesting read into how many variables are at play. But you’re right in that testing vapor products, (at least in terms of machinery), has already been done reasonably well.

The devil is in the details though, since there’s soooooo many different variables in each cartridge, the construction of them, the batteries, how they work together, how long a puff is, how much volume is in a puff, the acidity of the distillate, etc.

There’s also a section that expands on the difficulty of testing heavy metals with mass spectrometry, specifically arsenic and mercury.


Oh I definitely will, just can’t stop the only keyboard fingers from opening their stupid mouth lol

I do really think that testing what actually goes into your body is really important and often overlooked. After all, we’ve all had labs fuck our samples up in prep somewhere, it’s foolish to think it doesn’t happen when we actually vape things


I’ve never even found a lab that can do it with products containing cannabinoids. It’d be easier with nicotine products. I’ve always found it kind of messed up that this type of testing isn’t widely available for how developed the cannabis/hemp industry is at this point.

You can have a cart test clean for metals, oil test clean for pesticides/solvents, and use pure cannabis terpenes but you still don’t know what it actually going into your consumers lungs. Smoking/vaping products are pretty much the only consumer goods that deliberately get sent through a chemical reaction as they are actively being consumed.

Ive said it before but if anyone finds a lab that can offer this type of testing on compliant hemp products I am very interested.


The testing is already available for R&D purposes in Colorado. It does not cost thousands per test. Perhaps if you were doing the testing in-house, as the equipment can be expensive.

I built one of these aerosol collectors and utilized standard HM and TOC filter cartridges to test for this about 2 years ago. That’s what I had used in pharma for industrial health tests… so why not use it here.

Almost - it has to do with validating the “puff” / “draw” / “suck” so that it is always consistent. Which I found to be statistically different depending on the cartridge style, tightness of the preroll, and even type of cone (yes, I did it for smoke and vapes…cause it seemed important at the time).

Headspace I did not find good for anything related to Heavy Metals… perhaps I need to dig more into this. Still using ICPMS for heavy metals - in this case, digesting specialized collection cartridges I found to be challenging but not impossible.


yes, if you intend on capturing the aerosol on a “suitable filter”,
it is one thing to re-extract the cannabinoids another to re-extract
toxic heavy metals which may or may not find their way into
the aerosol. Shake with a two phase system of heptane-ethyl acetate and water?
Aerosols structure by simple, heated -solution vapor and air flow, may well be fundamentally different from vaping aerosols obtained though a “water” pipe.
it is not easy…
Everyone knows all those vape pens and cartridges from …xxx…
are pure as the driven snow.
I am curious concerning your filter pore size?

Vape crisis 4.0


I’m not surprised that headspace isn’t too great for collecting metals. Maybe some sort of SPME or a sample through a solvent bubbler would work. I think that repeatability is definitely an issue with a sample that way but we’re also probably looking at “orders of magnitude” screening.

I actually utilize a system that has two separate parts. Its the same system I’ve used for industrial hygiene applications (Check me out) You purchase the cartridges - the cartridge then fits inside your pumping apparatus. Once you are done collecting the sample - you open the cartridge and digest the inside.

Here is a specific example of one I have used before - but I usually go with whichever ones are available at my local safety shoppe, so I don’t have to wait for them to be imported. They are all made to the same standards I believe. :slight_smile:

If I’m trying to measure for something that doesn’t work with the materials in the cartridges I have on hand - then I will make a special request to the manufacturer. They have other types of seals and they have some filter paper that is not made of cellulose, if its really necessary. I haven’t found it to be necessary for testing prerolls or vape carts. -shrug-


Emissions testing SHOULD be done. Colorado will require it in a year or so I believe.


These guys in Canada do it for cartridges. Less than or around $1000 for vape cartridge safety testing if I remember, I asked for a quote July-ish. No excuses this industry needs to head this way.

Let me save you guys some clicks because I really think we should ALL be running this type of testing. No I’m no shill for this lab, no affiliation at all, and my people did not end up going through them. I was calling up labs and a few pointed me to this one.

Labstat_ Primer to Vape Testing.pdf (1.4 MB)

Labstat_Vape Testing Onboarding Questionnaire_2020-07-15.pdf (146.5 KB)


How often is this testing required though? The interbatch variation we see with carts is enormous already, for me to feel like I was really quantifying this would take a fuckload of testing. I hate mandated testing that is totally unrepresentative

I do not know about requirements sorry. I was looking at doing it to guarantee the safety of some hardware prior to requirements.

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I agree it’s really important to test, I just cringe at the idea that it would be part of my compliance testing because it would be a fucking nightmare lol. I have much more faith in our own discretion to evaluate what is the “worst case” for a manufacturer with an effective sampling plan than some requirement written by a state rep that never took high school chemistry

Just some emperical obsevations:
I have used laser plume filters, nominal pore size 0.1-0.2u
to intercept aerosols produced by water cooled vaping pipe.
These pipes produces a robust aerosol. This type of aerosol does not pass these filters. (cat. 65651-803 Laser Plume Filter).
Moreover there does not appear to be any cannabinoid vapor
(non aerosol) that passes (bioassay). Which means either the cartridge provides an effective adsorption surface at low nano scale (impact plus diffusion) in addition to the sub micron filtration , or there is no cannabinoid vapor in the classic sense. It is all aerosol.
If you closely watch the vapor trail of purified cannabinoid as it passes down the pipe-stem to enter water, and then exit instantaneously as an aerosol…it is rather awe inspiring.
Moreover , it is quite clear that no human has ever enhaled a non-aerosol structured cannabinoid vapor. And if you could it would be in aerosol form by the time it hit the lower respiratory tract, cooling and interacting with the humidity present.
More simply put: you can “smoke it”, but you can not “woof it”.
There is a lot of room at the bottom…
nice intro to the aerosol chem…contaminants.


The real mystery is how you were allowed out of your enclosure


“the’re just questions Leon, in answer to your query they are written down for me.”
VK test

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