You don't need tonnes of it to be extremely toxic. The stench of it even from a properly burning engine is extremely nasty and sickening. I'm talking about the

You don't need tonnes of it to be extremely toxic. The stench of it even from a properly burning engine is extremely nasty and sickening. I'm talking about the trace residue that you get from non-stoichiometric burning in the engine. Add to that all the excess added as guidance margin and whatever is trapped in the plumbings.