Kallitype (terryroth@earthlink.net)
Sat, 02 Oct 1999 10:02:57 -0700
Lee, Jonathan wrote:
>
> A 5N (normal) NaOH is 200g/liter sodium hydroxide. A 50% solution is
> 500g/liter. Provided that it is kept sealed, there should be no problem
> using this solution more or les indefinietly. Wear gloves and eye
> protection, lab coat if you have it. As NaOH solutions go, a 5N isn't that
> nasty or odorous but can cause skin burns.
>
> Jonathan Lee
>
> -----Original Message-----
> From: Nick Makris [mailto:nick@mcn.org]
> Sent: Saturday, October 02, 1999 12:16 PM
> To: Alt Photo
> Subject: RC negatives - stripping paper
>
> Hello again,
>
> Not so long ago, I read a post from Peter Fredrick regarding the removal of
> the emulsion from the paper backing of RC prints. While I have successfully
> accomplished this at times previous, he went one step further by suggesting
> the use of Sodium Hydroxide at 50% to further clear the paper.
>
> Not being very chemically minded, I have a question(s) regarding the
> strength/safety aspects of the material I have on hand. I found a plastic
> pint bottle of liquid Sod Hyd in a cupboard in my darkroom - has always been
> in the dark. It is heretofore unopened and was manufactured in 1980. The
> strength is declared at 5.000 Normal.
>
> If you would be so kind, I would like to know, 1) if this is the same stuff
> that was recommended and is the shelf life ok? 2) use it at what dilution?
> 3) besides gloves, what other safety precautions should I take??? This the
> only chemical that I have that talks about severe burns on the label,
> however, it says nothing about ventilation. I will appreciate your
> comments.
>
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wear eye protection!! WEAR EYE PROTECTION!!! Rubber dishwasher
gloves will be fine, but fer sure: wear goggles or
safety glasses with "side shields"!! Many years ago I was a research
lab manager, and had to deal with a person who got just a "teeny
splatter" of 2N NaOH in the eye. It was a very unpleasant experience
for all concerned. THis was back in the 1960's when we pipetted serum,
acids, and other noxious stuff by mouth! We learned from this.
If I had to choose, I would handle this stuff bare-handed and pipet
by mouth rather than skip the eye protection. 'Nuff said!
This archive was generated by hypermail 2.0b3 on Fri Nov 05 1999 - 21:26:26