If anybody is worried about toluene, give Xylene a try .Not much difference, but I have extensive personal experience with the latter.
I've personally used it (Xylene, that is) in half a dozen performance vehicles with both standard fuel tanks and plastic NHRA approved fuel cells. No soot, no fuel system problems, and one hell of a lot of fun once I got the tuning for my engine sorted out.
The majority of the time I ran 25% Xylene, 75% 92 octane unleaded gasoline. But on occasion would run up to 33% xylene, never more because it was no longer cost effective when compared to race gas available at the drag strip.
I know gents who have used toluene, but it isn't readily available near me.
FYI, one of the fist things I did when I bought my new-to-me RIB was throw 4 gallons of xylene in the 20 gallon tank. I've found over the years that Xylene cleans out fuel systems WITHOUT braking up varnish/deposits into particles that clog carburator jets and fuel injector spray patterns. They simply dissolve.
In case it's not apparent by now, I'm a believer. lol!