Thanks for that guys
CC: wow! What can I say -that is an eye-opening bit of reading!!! I've had the misfortune of working with toluenes and other carcinogenic compounds in the past; they are seriously scary substances. IMO you can't take enough precautions to protect yourself around these things, and here we are adding it to our fuels in place of a substance 'all-but' proven to be non-harmful.
Catalytic converters? Hate the bloody things. My car is a twin-turbo, originally equipped with cats. Due the nasty habit of cats to block at the end of their useful life, pressure-pulsing the turbos I chose to cut mine out, replacing that section of exhaust with a resonator. The only 'loss' was the O2 sensor, (integral in the cat assembly) which results than a slightly richer than ideal mixture. Still searching for a way to replace the sensor -or another means of controling the mixture!