Here is an interesting article by Doug Cody at Cannabis Home Sciences on his extraction solvent research. In it he goes into depth showing why Isopropyl Alcohol and Acetone are safe solvents to use extracting cannabis concentrates, and identifies FDA maximums considered safe after purging.
He compares the FDA Permitted Daily Exposure (PDE) for Ethanol, Ethyl Acetate, Isopropyl, and Acetone to demonstrate that exceeding them is unlikely from residual solvent in concentrates and that none are of health concern at the levels typically present in concentrates.
He identifies the metabolic derivatives of the four solvents tested, and that while Ethanol is Generally Regarded As Safe (GRAS) by the FDA, our livers metabolize it into Acetaldehyde, which is a genotoxin carcinogen, and a teratogen, the World Health Organization (WHO) says that there is no safe dosage.
He notes our bodies relatively high tolerance for acetone, which is what Isopropyl alcohol is metabolized into by our livers, which our bodies produce naturally when burning fat, and has a relatively high tolerance for and while toxic at drinking dosages, is not genotoxic, carcinogenic, nor teratogenic.
He further compares the dosages of those solvents lethal to 50% of population tested, further demonstrating that the LD-50 levels required, are 2200% to 3500% of PDE.
I ran Doug’s numbers by my favorite licensed Parm D, who pointed out that “the numbers are good guidelines but are extrapolated from animal experiments as well as numbers gleaned from intended or unintended human exposures (like suicides and accidents). The estimates are best estimates and they are all we have.
While we shouldn’t worry about 50mg of solvent in a gummy…. we also can’t say with scientific certainty that it is SAFE, only that it’s far, far below the levels that we know can cause acute harm.“
She also pointed out that not only does the dose make the poison, but the route plays a big role…how much can get in at one time and how fast it uptakes when it gets there?“
Here is Doug’s article and numbers:
https://www.cannabishomesciences.com/solvents/solvent-safety-for-gwl