The thought is legitimate however.  Tests for cancer inducing
    potential are expensive to conduct so they are run with doses
    just short of lethal.

LD50 doesn't have anything to do with cancer-causing potential.  If the
MSDS says it's a carcinogen, you really have to dig to find out what that
really means.  (for example, dichromates have a dangerous reputation, but
you end up noticing that the data is that chrome plating workers, who work
near huge vats of the stuff, for hours every day, end up having a "higher
incidence" of mouth and throat cancers.  Fine.  Reasonably nasty stuff, but
I don't think I need to go the full hazmat clothing route to use some
dilute solutions for assorted photography experiments a couple times a
year.)  I really, really, HATE MSDS.  All they end up telling you is
"everything is dangerous", a view that induces either paranoia or
complacence, and is therefore dangerous in itself.

BillW

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