I wonder if this reddit comment was on to something: https://www.reddit.com/r/CannabisExtracts/comments/b1w76g/tr...

Some background information:

- Cannabis, particularly THC, extracts are quite viscous and require thinning in order to feed into a vaporizer’s heating element. In other words, even for very pure use, some thinning is necessary.

- Thinning agents include propylene glycol (PG) and polyethylene glycol (PEG), also commonly used in nicotine liquids

- A market for terpenes as a thinning agent has emerged amidst uncertainty about the long term effects of PG and PEG

I wonder if mineral oils sold as terpenes are behind the lipoid pneumonia as the commenter mentions. Considering at least some of the carts were tested to be of advertised potency, I could conceive of a contaminated batch of “terpenes” making it into a well-meaning producer’s cartridges.