On Mon, 14 Dec 2009 19:17:28 -0500, "Ed Huntress"
wrote:


"Richard J Kinch" wrote in message
...
Ed Huntress writes:

I thought that's why people used hydrofluoric
acid for small-batch passivating. Hot nitric is very nasty stuff.

And cold HF is even nastier.

But isn't it safer to handle, at least because of the cooler temperature?
And how about the fumes? I don't know the answers to these questions; I'm
just asking.

I'm OK with fuming HNO3 but I wouldn't mess with HF outside of a
properly-equipped lab. Quote from Wikipedia:

The danger in handling hydrofluoric acid is extreme, as skin
saturation with the acid in areas of only 25 square inches (160 cm2)
may be relatively painless, yet ultimately fatal. High concentrations
of hydrofluoric acid and hydrogen fluoride gas will also quickly
destroy the corneas of the eyes.