My advice would be to make a test batch with a two-fold process:
Put like 1g in a vial with 70% alcohol and swirl/agitate it to break up any clumps, then let it sit for a couple minutes. Dump it on flat aluminum foil and cover with a foil tent to prevent dust from falling on it as the alcohol evaporates.
Dissolve in oil, filter.
This should take care of bacterial and other contaminants as well as any breakdown products.
Test with a tiny (<0.1 mL) injection shallow subq. That way any chemical or biological issue will be apparent and superficial.
It's been left to exposed to open air. For easy reference, the volume of adult breath contains roughly 500000 bacterial cells, fungal spores, and viral particles. After years of exposure and air settling on it, there will be biological contamination. Despite the low water activity and limited nutrients, some viruses, fungal spores, and endospore forming bacteria can survive on surfaces for months to years.
So while it's true that raws have been tested over and over and over, I don't think Jano has run his buddy's closet air through an HPLC.