Cleaning SOP? Removal of pesticides from equipment

Hello all,

Pretty new to this forum but I am seeking out for some advice. I have recently received test results for a distillate batch and noticed that myclobutanil and piperonyl butoxide tested positive and were 155x over the legal limit. Now, this was not my material, this is from a so called “commercial” company who gave us fake clean test results, which concerns me because who else is doing this? Anyways, we ran the material through our closed loop, rotovap and short path distillation and I am super worried about future batches. Really not trying to buy new equipment because it is hella expensive. Does anyone know anything about removing the pesticide from our equipment? Only concerned with cleaning the equipment to prevent future runs from being contaminated for our patients. The distillate is already removed from play and trashed. I called around and no one really knows the best way to clean the equipment so I figured I’d reach out to this community. Would appreciate some feedback, thanks!

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Thanks for the info! I’ve reached out to some people and was told solvents like ethanol, acetone, and heptane should help too. Do you know if those methods would apply the same to stainless steel? Or should I just replace it? I’m not really trying to risk anything, especially after seeing those results. But also spending another 15k on glass and stainless is quite the expense.

you should be able to achieve an acceptable reduction in contamination using several sequential washes with a couple of those solvents followed by a decent detergent and lots of clean water.

so long as you remember to clean everything.

don’t forget that you’ll also need to dispose of that contaminated solvent. incineration is most appropriate.


Okay sounds good. Already in the process of getting rid of the contaminated solvent. Thanks for the feedback and linking that other forum, definitely helped me out.

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I was referring to the solvent you are going to use for cleaning.
not the solvent you’ve got in your tank.
but you’re correct, that should probably be on the “to go” list as well.
depending on you level of paranoia.

I don’t have any data on either of those two as far as co-distilling with butane.
I would not expect them to. I’d probably vent and clean my tank anyway.

you can also use 3rd party testing to convince yourself that you’ve gotten the job done by taking swabs.

Edit: for the record. given the way pesticides are distributed and concentrate, a biomass provider doesn’t have to be submitting bullshit test results to have clean COA’s on material that will test hot once extracted. As an extractor you need to be aware that “clean” testing biomass can produce dirty extract.


Rather be safe than sorry. Will dispose of everything contaminated/replaced. I’ll definitely look into doing the swabs. Good to know, figured since you are breaking down the biomass to a single chemical, other components, such as pesticides, would be more prevalent than in flower form.

There are several go tos for glassware cleaning in an organic lab.

I would recommend an isopropyl alcohol/solid KOH base bath. You can do this in a 5 gallon polypropylene bucket. There should be a recipe online or DM me for mine. Use long protective gloves (I use butyl rubber). Soak for a few hours to overnight, then wash with water until the base residue is gone. Then water with Alconox detergent, you wash with an acidic chemistry detergent too. Citranox is one such brand. After detergent, DI water, and then acetone. Dry in hot oven = done.

Nuclear option is aqua regia, nitric acid in HCl, but I’ve only ever needed this to clean filter funnels. This is a potentially dangerous reagent and don’t use it with a fumehood and proper PPE.


In the future when working with a new client never use your CLS or other aspects of your lab. Instead open blast a very small amount of their material and send that off for testing. If it passes all tests you can than extract on your big equipment. Someone on this forum gave me this advice and it has now saved us more than once.

A lot of times flower/trim can pass pesticide testing and only have small trace amounts of pesticides. When extracted this small amount will increase and often make the extracts fail. So again to be safe just do a very small open blast extraction and than send that off for testing. Thats the only way to truly know.


Use non-volatile solvent or do a small closed-loop extraction🤷

How do you incinerate contaminated solvent? I have a bunch I need disposed of. Just a propane torch?

So acetone then an alconox soak overnight cleaned with fresh water should work?

For future reference… best to get a pesticide report for EVERY batch of trim you’re going to process that was not grown in-house or via contract to not use said components.

$30 to save anyone this kind of trouble is always worth it in my opinion.

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This was all single source, I hadn’t seen problems in the past and they claimed its clean. They are always getting new clones though. Should I be testing new strains as the flower out?

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I test literally every batch that comes in personally… The trouble I would go through cleaning a Waters SFE is obscene.

If they got you once, they’ll get you again. All it takes is a new grower not knowing how to deal with a problem and taking the easy way out. That’s why contracts are nice, if they send you hot trim, then there’s repercussions.


Ideally you’d leave the setting on fire to a licensed disposal facility…

Although a controlled burn on your terms is certainly better than your waste solvent finding a source of ignition on its own.


I’d go with @drjackhughes suggestions


Hexane soak the cls for a few hours at a time & thoroughly clean the system out by hand with acetone & etho. This will take a course of a few days to properly decontaminate. Boiling the flasks is extremely dangerous & I wouldn’t suggest doing so unless you’re in a c1d2 location. Volatile gas off can be way to unpredictable. Best to just soak all glass ware in acetone & etho base with 5 gallon buckets as suggested above, you will need proper PPE. Suit up boot up, gas respirator, the world my friend. After a weeks worth of washing & cleaning all top to bottom, I’d do a swab test & “water test” on your ppm. DM if you need help.

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There should be a county facility that can intake flammable waste. Call it what you need to. Better than burning it yourself.

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No facility here. They also skipped Hazardous Waste Days last year and the next isn’t till November. What do you think? Set it up to burn or is there a way to ship it to someone who will dispose of it.