https://potguide.com/blog/article/pg-peg-and-other-vape-cartridge-additives-are-they-safe/ >By making the oil compliant with these devices, manufacturers introduce potentially unhealthy chemicals into the cannabis oil. The most common and criticized cutting agent is polyethylene glycol (PEG), which can contain ethylene oxide. Similarly so, propylene glycol (PG), which is used in the production on polymers and food processing, is often added.