[ajbeach22]

Super critical co2 is also used for caffeine extraction in coffee, and its safer solvent for cannabis extracts and concentrates. I would never buy cbd products unless they are lab tested with a GC for contaminates and extracted with co2.

[lightedman]

Look into USP-grade acetone-extracted cannabinoids. Acetone is 100% VOC so it will evaporate away cleanly without needing a vacuum purge (I'd still heat it to 135F to boil off the acetone which boils at ~133F) and your body naturally produces it in small amounts, so a tiny bit of contamination isn't going to be likely to cause damage. It is cheap to obtain vs. compressed CO2 (the cost of the equipment required for CO2 extraction represents the bulk of the cost of the extract) so you'll also save money.

Many places that do CO2 extraction also don't use a closed-loop system, so many are just venting the CO2 directly into the atmosphere.

[fuzzfactor]

Take a look at the USP Acetone specification, it does not indicate definite ideal suitability for the task:

https://greenfield.com/wp-content/uploads/2018/11/Spec-Sheet...

This fungible specification has no specific limit for Diacetone Alcohol content, a common impurity and one which increases during storage.

Diacetone Alcohol is an industrial solvent with properties of its own, not nearly as low-boiling as Acetone. Clean Diacetone Alcohol will also show negligible Residue After Evaporation and Non-Volatile Residue under conditions of the tests, which report mostly solids content along with many higher-boiling liquid impurities but not components as moderately volatile as Diacetone Alcohol itself.

However Diacetone Alcohol can still be a significant component of the extract once the bulk Acetone has fully evaporated, depending on the conditions of the processing. Rotovap would help a lot and more than 135F would reduce residual solvent better from a viscous matrix.

The USP Purity minimum of 99.5 basically means that the water content plus any other chemical impurities such as Iso-Propyl Alcohol & Methanol (specified) and implying things like Diacetone Alcohol or Benzene, etc (but unspecified) must not add up to more than 0.5 percent.

You might even prefer to explicitly specify a maximum limit For some other target toxins, less than some low detectable amount if you were picky.

Some legitimate laboratories may not be able to detect the difference between Acetone which contains unlisted impurities and that where it is negligible.

Take a look at the associated weaselwords from legal:

https://greenfield.com/wp-content/uploads/2018/11/OVI-Residu...

Which references this as the closest applicable guideline, even though it was intended to apply to the residual solvent content of pharmaceutical products not solvents themselves:

https://www.uspnf.com/sites/default/files/usp_pdf/EN/USPNF/g...

Better than nothing but not as cautious as it could be. You may want fewer impurities than marginal drug companies anyway, you're allowed to do that. This particular supplier does look nicely better than marginal, which is good, with typicals looking well better than the limit.

Regardless with two lots of USP Acetone having apparently identically suitable certificates, one may result in its Diacetone Alcohol or other not-so-volatile components comprising a significant portion of the extract, while the other lot would not, under the same solvent-removal conditions which are excellent for the latter batch of Acetone having only the lighter impurities such as IPA & Methanol.

I would still want to test it myself first.

Source: pioneered laboratory techniques which some other testers and chemical plants eventually adopted years later, still state-of-the-art today, including this particular material. Certified billions of dollars worth of commodities like this, single-handedly more than some single petro-chemical companies can manufacture. Less than a year ago deployed a further advanced system with two backups for 100 percent uptime in a 24hr staffed operation, for when a big oil/chemical client has their ships come in, and it was Acetone. There is still no adequate publication within ASTM, been at it since dirt was rocks, and Acetone has been around even longer. Documentation not found elsewhere.