Sulfuric acid
is much more dangerous than sulfurous acid. Remember,
Johnny was a chemistry student, now Johnny is no more. For what he
thought was H2O, was H2SO4.
Actually, none of the common mineral acids (hydrochloric, sulphuric,
nitric) are particularly toxic if dilute. There are plenty of chemicals I
would not drink in solution (no matter how dilute), but those 3 acids are
not amongst them. They wouldn't do me much good, but they'd not kill me
either.
The main hazard from such acids is, of course, that they tend to
'corrode' you if concnetrated...
That's the hazard to which I refer. When concentrated, you're usually
dead before the toxicity can cause too many problems.
Peace... Sridhar