My chainsaw runs on Aspen, which is a synthetic replacement for gasoline. It doesn't cause a headache when I'm exposed to the exhaust fumes for long times. It's quite expensive though, about 4€/l (15€/gallon).
Aspen2 is not green. its Aspen 4, which is part of the gasoline distilation process, but the oil they mix in for the 2 stroke engines is a syntetic bio oil.
https://www.aspenfuels.us/knowledge/what-is-alkylate-fuel/wh...