The main reason I asked is because of the experience of a friend of mine who was doing stove testing with isopropanol ("rubbing" alcohol) in his garage. He became quite ill. It took him a couple of days to feel better.

I've done very little experimenting with isopropanol for that very reason (my friend's experience) and the general reputation that isopropanol burns with a lot of soot. Nothing I've seen or read has encouraged me to try further experiments with isopropanol although maybe I should revisit that.

With respect to toxicity, it makes sense that "rubbing" alcohol wouldn't be too toxic although I know it is quite toxic if you drink it. The combustion by-products, not the ispropanol itself, are what seem to have made my friend ill.

HJ