Most of the pot for sale on the street in East Palo Alto California contains this stuff. Everything you described about it including a burnt plastic taste is present.
It’s being sprayed on short-term cultivation synthetic cannabis that tosses and I did an inspection for its maturity. What I found was it never reaches maturity as a growing plant. They add a copious amount of industrial chemicals into it which makes it a more marketable product. Addition of chemicals make it more life threatening.
I smoke the stuff for 25-30 years and it has brought me great joy and pleasure in my life. But now, it seems like there’s not a single solitary thing available at an affordable price that is not fortified with this garbage.
All the people that are selling this are clearly connected to the countries of origin that this dangerous synthetic cannabis or spice is coming from.
Stay away from these people and the dangerous stuff they are selling!!!