The Pyrethrin Conundrum

Hi all,

first off, probably didn’t put this thread in the right category :frowning:
Also, I know there are other threads, I have read them. I would love some help, but I am also just looking to discuss with peeps who live in my world. Bang some ideas around and see if anyone has already tried what I’m thinking of.

Got a couple batches of CO2 oil with pyrethrins. After reading everything I can find on here, doing some other online reading I do believe I am, whats that word… boned?

We do not have space for reverse phase, licensing or proper facilities for hexane/heptane and the research I’m seeing is showing that wouldn’t help anyway. I will not intentionally bring any toxic solvents into my lab. We have a kitchen in the same building and I try to have a clean, safe work environment. I know, making this very easy :slight_smile:

Insoluble in water, so no help there. Soluble in ethanol, but so is the oil so no help there. Possibly binds to some adsorbent media, didn’t see much to indicate it works efficiently with any though. I have a few options for media so may play around some but my time is pretty well filled up.

The one possibility I saw that looked interesting: heat / light

Yeah, I know I’ll have cannabinoid loss. Less concerned about that then destroying the pyrethrin. CO2 oil isn’t particularly high potency straight out of our old extractor so some loss wouldn’t be an issue. I am thinking of diluting in alcohol, heating and running under UV light. Crude, but might be effective. This was tested flower so I am allowed to dilute it but I would prefer not to mess with clean oil.

I saw a few mentions of hydrocarbon extraction pulling less pesticides, but based on structure it’s hard for me to see it being significantly less solvated by the hydrocarbons than thc-a. Not an organic chemist so I will admit my appraisal could be off. I mention this as we are finishing our buildout to move from CO2 to hydrocarbon.

A guess is the heat/light breaks the central oxygen bond. It’s not elegant, it’s not what I want to do, I would like all my input material to be clean… but LOQ is LOQ and concentrating is concentrating.

We are a small business so a loss of 8 kilos is somewhat painful. The money loss is bad, the time lost producing is even worse.

Thoughts? Comments?


Sunlight for sure. I’ve had decent success just running it through carbon filters as well.

Good luck!


Can you designate it for edibles? After dilution the pesticides may not be detectable.

What level of pyrethrins are we talking about?

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Do you know exactly which compounds were in it? Natural and artificial “pyrethroids” are structurally different. From the little I’ve gathered their boiling points look to be 20-50C higher than THC. At least one looks to be a little lower so that’s why I’m curious if the lab can tell you exactly what they found. Doesn’t look like they would be easy to remove with solvents alone

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I can dilute and use in edibles but in Oregon you must test and the most concentrated. I can only dilute oil in oil. It was at 3 ppm, needs to be under 1. Definitely able to remediate with dilution.

The report only says “pyrethrins”. Permithrins are a separate test but doesn’t specify. I think I’ll call the lab and ask! There is no straight solvent answer. I need to find out more about pyrethrins and adsorption. Can I get my numbers low enough with acceptable loss or does it just pull material in the same concentrations.

I’ve had success remediating using a filtration stack of spherical carbon and spherical silica. Silica on top, carbon on bottom. 86% hexane/heptane 14 % distillate.

EDIT: if you’re not using a pressurized column you can probably get away with non spherical, granular media which is much cheaper.

if you’re interested in packing your own columns rather than buying the pre pack:

heres the carbon, runs about $60 a kilo:

Here’s the silica runs about 275 a kilo:


Thank you!

I have granulated carbon, silica and some magsil that we buy direct by the metric ton. Might have a couple other items. I am trying to avoid the hydrocarbon solvents though, concerned about disposal.

I was thinking of trying a variety of media and dissolving in 200 proof ethanol. I know the pyrethrins solvate in ethanol but was considering the polarity could bind it to strongly, hence your hydrocarbons solvents lol

UV light source can degrade. UV B/C

Have oil stirring well and angle a sterilizing light at it for an hour. basically.

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thanks, my thoughts too.

Let the trials begin!

I didn’t dilute in ethanol.
Heated oil to ~100c - to stir well.
Seems to be around 1ppm remediated per hour - haven’t had to work on anything above 3-4ppm.
Potency didn’t degrade as much as I thought it might, if at all.
Color is affected - shifted towards red
didn’t redistill

Hope this helps,



Maybe sunlight and using an amber glass shield. Idk if that would work but… amber glass protects right?

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it all helps :slight_smile:

Bringing my UV light to work tomorrow to do some testing. Red color is meaningless to CO2 crude lol. Will get the test run soon, see if this is a solution and post.

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I guess I should mention this was done on CO2 produced distillate - was in distillate form at point of remediation.

This is straight up CO2 crude. Might dump it into a reactor and run it for a couple hours under the uv

Im Guessing if you introduced a sweep gas like argon or nitrogen you could prevent the color shift as well.

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i’ve got the media available to remove pyrethrins using heptane. DM me for details, you can clean that one easy!

ok, will do

nitrogen purge always

You got me interested because there were a few times I was using my rotovap with my grow tent open while it was in veg so it was in the full blue spectrum. So my whole room that i was doing the rotovap in was blue a few times I’ve rotovapped. It didn’t seem to ever really make a difference to the oil because it wasn’t directly exposed to the blue led but still wanted to toss this out here.

Would your media also help to remove Piperonyl Butoxide? Some of my distillate came up hot for both.