I’m sure some of you have experience with large amounts of dust created during grinding, or other processing steps. One thing we need to keep in mind during these processes is that dust is often explosive! For example, you can even take good ole all purpose flour, toss some in the air, and ignite it!
Unfortunately, there is not much data out there for how cannabis dust acts when exposed to an ignition source. Does anyone have any info about Ignition Energy and/or Kst values of cannabis dust at various particle size?
This is actually a know thing! The published Minimum Ignition Energy of cannabis sativa is 30mJ. This was published in 1977 with a whole bunch of other combustible dusts. You can read about it in: Haase, H. (1977) Electrostatic Hazards, Their Evaluation and Control, Verlag Chemie, Weinheim.
There is limited discussion about particle sizes (its a broad range of 0.5 micron to 10 micron). And its only specific to dried cannabis - but you wouldn’t really expect clouds with wet cannabis would you?
And then of course there is the whole - other chemicals aspect. For instance - if you were collecting and somehow aerosolizing your kief then you might have to consider that as a separate thing (its not the plant dust anymore…its a more isolated chemical compound).
There is also a mention of “Hemp” in the NFPA and the IFC that discusses the cloud and layer ignition temperatures. You could always start there and treat it like the Class II, Group G that it is registered under.
I’ve had to have these tests done many times while making sure a room is classified appropriately for the products being produced within - especially when they are not on published lists. Companies like Fauske can help - there are others. And you can even get a fire safety specialist to perform this specific to your equipment, dust production, and expected environments (humidity levels, temperatures in the space, etc.)
On the flip side - its not hard to ask vendors to make equipment with dust wetting technologies and there are definitely vendors out there that will retrofit equipment with issues like this. Including one of my favorites ILC Dover - they do all kinds of containment projects for hazardous dusts (explosive, toxic, etc.).
Wow thanks so much @Cassin! This is all very helpful. We were considering hiring someone to do the test for us, but unfortunately are pretty limited on who is allowed to handle our product, even for simple tests like this. I didn’t think testing it ourselves was feasible, but thanks to you I’m reconsidering. In the meantime I’ll look into some of the resources you’ve provided and go from there. Thanks a bunch!
