One point bears repeating.
Acids are far from the only thing that can eat away at your skin or
cause massive skin irritation. Potential for harm is not by any
means measured by pH.
Concentrated habanero pepper extract will cause extreme pain, but it
is neither an acid nor a base. Neither is Flourine or Chlorine
gasses, pure Sodium, and a whole category of other things that a real
chemist could fill you in about.
Even concentration is not enough to go on. A little mercury is only
mildly harmful and can be safely chelated out of your system.
However, if Mercury is in the right form (Dimethyl Mercury, for
example), it's fatal and can even seep through rubber gloves. An
accomplished Prof. of Chemistry was working with Dimethyl mercury,
spilled a few drops on her gloves but cleaned it off immediately.
This was enough to kill her 10 months later, after much medical
The overall suggestion? Treat every chemical like it could kill you
and you will be safe.
-- Ken, back from spending a day out in Golden Gate Park watching
Duran Duran, Seal, Liz Phair, and Maroon 5, so he's therefore too
tired to post a pun or snappy remark in his tagline.