Re: Liver of sulfur?

From: John ^lt;ap@darkroompro.com>
Date: 11/01/03-09:36:59 PM Z
Message-id: <1odf0yj23zemz.1e7k2mxx0ui1e.dlg@40tude.net>

On Sat, 01 Nov 2003 19:31:30 -0500 (EST), you wrote:

> Polytoner is the only polysulfide based toner I've used, and I found the
> odor very slight, whether because of the dilution or absorption by the
> bricks in my darkroom I know not.

        From what I understand the odor can be affected by the pH. The higher the
pH the less odor. Acid or low pH causes the release of hydrogen sulfide which
is annoying for good reason as it can be instantly deadly under concentrations
higher than 700 ppm. In fact it may be deadly in concentrations as low as 50
ppm according to USC's report at ;

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=96104950

        BTW, if one is suddenly exposed to a very high concentration (150 ppm or
higher) it is possible to overwhelm the olafactory nerves and for someone to
essentially not even know what is killing them.

-- 
Regards,
	John S. Douglas, Photographer
	http://www.darkroompro.com
Received on Sat Nov 1 21:37:09 2003

This archive was generated by hypermail 2.1.8 : 12/04/03-05:18:02 PM Z CST