From: Clay (wcharmon@wt.net)
Date: 02/20/03-02:01:25 PM Z
That book is considered a mite 'hysterical' by many alt-photo workers. While
care is obviously needed, the tone of the book does seem a little too
sensationalist. I understand she now works for the department of homeland
security.
----- Original Message -----
From: "DENNIS KLINKER" <dennis@klink47.freeserve.co.uk>
To: <alt-photo-process-l@skyway.usask.ca>
Sent: Thursday, February 20, 2003 10:13 AM
Subject: Re: Aqua Regia & safey
> Gordon this is a good idea,i am sure with all the expertise on this list
it
> will not be a problem,can i bring to your attention the book
"Overexposure"
> Health Hazards in Photography by Susan Shaw and Monona Rossol published by
> Alworth Press ISBN 0-9607118-6-4 although i could not see any mention of
> Aqua Regia there is a chapter on Photo Alt.
> Dennis Klinker
> ----- Original Message -----
> From: "Gordon J. Holtslander" <holtsg@duke.usask.ca>
> To: <alt-photo-process-l@sask.usask.ca>
> Sent: Thursday, February 20, 2003 3:29 PM
> Subject: Aqua Regia & safey
>
>
> > I received a lot of private email concerning Dick Sullivan's recent
> > posting entitled "Kitchen brewed gold chloride! Not!" (Feb 10 2003)
> > about the safety of working with Aqua Regia. A copy of his posting is at
> > the end of this message.
> >
> > This stems from an article entitled "Make your own Gold Trichloride"
> > written by Liam Lawless, published in the World Journal of Post-factory
> > Photography in May 1999 (page 30). In this article Liam Lawless
> > summarizes a method in which gold trichloride is produced from "scrap
> > gold".
> >
> > As others have noted Liam did not suggest doing this procedure in the
> > kitchen or darkroom. His procedure also avoids the problems associated
> > with storing Aqua regia by neutralizing the aqua regia solution at the
end
> > of the procedure.
> >
> > I considered how other publications associated with alternative
> > photographic processes dealt with issue of working with hazardous
> > chemicals.
> >
> > I did a "review" of many of the alt-photo web sites, those written as a
> > public service and commercial web sites, as well as a number of books.
> > Almost all of these give some sort of warning that many of the
> > chemicals used are hazardous and that people should assume everything is
> > hazardous unless they know otherwise.
> >
> > None of the sites I visisted provided any specific information on how to
> > deal with the potential hazards. Most sites didn't even identify which
> > materials were hazardous and which were not.
> >
> > Liam's article, like most other alt-photo information currently
available
> > assumes the worker is aware of the hazards involved.
> >
> > On the alt-photo list its assumed that everyone knows how to handle the
> > potentially dangerous chemicals. When we post a message about salted
> > paper we don't describe the hazards and necessary precautions to be
taken
> > when working with silver nitrate. The same for dichromates in gum
> > printing and so on.
> >
> > A lot of the people working in this field come into it with some sort of
> > training that informs them of the appropriate laboratory/chemical
> > practices. As alt-photo becomes more popular, this is becoming less and
> > less common.
> >
> > The lay-person starting to work with alt-photo can usually find plenty
of
> > information about the hazards, but little information on how to work
> > safely in this field.
> >
> > What I would like to see is an effort to properly document the potential
> > risks of each process, the basics of the chemistry involved (why there
is
> > a safety risk) and the appropriate steps that should be taken to
minimize
> > the risks.
> >
> > If people are genuinely concerned about providing indepth safety
> > information, perhaps list members could collaborate on producing
> > documentation on the proper safe darkroom/lab practices for each
process.
> > I would be happy to post these on the alt-photo archive site.
> >
> > Since the use of Aqua Regia is such a concern, perhaps we could start
with
> > this process. At this point anyone going through the archive looking
for
> > information on aqua regia and gold chloride will get the left with the
> > impression that some people think its dangerous and some people think
its
> > not.
> >
> > I would like to ask the people who have worked with aqua regia and gold
> > chloride to collaborate on a document that clearly outlines the hazards,
> > and the appropriate precautions. If people are unable to agree I would
> > like to get dissenting opionions, and post these.
> >
> > I will post one or more documents on the alt-photo archive site.
> >
> > If people are unwilling to do this then I would insist that the issue of
> > Aqua Regia safety should no longer be discussed on this list.
> >
> > Thanks
> >
> > Gord Holtslander
> > List Manager
> >
> > On Mon, 10 Feb 2003, Richard Sullivan wrote:
> >
> > > Subject: Kitchen brewed gold chloride! Not!
> >
> > >
> > > Several years ago there was a brouhaha here over an article in Post
> Factory
> > > No 3 on making gold chloride in your kitchen or darkroom.
> > >
> > > The issue at hand was safety. I believe some correction were made in
No
> 4
> > > but the problem still exists as many here might read No. 3 without the
> > > benefit of the corrections in No 4. It is highly doubtful that anyone
> would
> > > try this trick at home but someone just might as the article proposes
> just
> > > such a project.
> > >
> > > Several had said here that aqua regia would not explode in closed
> > > containers. Wrong!
> > >
> > > Liam Lawless, author of the article, said the following June of 1999
on
> the
> > > list via another members repost or forward.
> > >
> > > Liam says:
> > >
> > > >We have perhaps been remiss in implying that this process can be
> carried
> > > > >out indoors, which it definitely should not without the proper
> equipment,
> > > > >etc., but the only other point that gives me real cause for concern
> is your
> > > > >assertion that stored aqua regia could explode.
> > >
> > > Not only my assertion but that of the American Industrial Hygene
> Association!
> > >
> > > >I have, therefore, spoken
> > > > >to a chemist about this today (whose name I shall not give as he
has
> > > > >nothing to do with this debate, but who has some interesting views
on
> > > > >safety and responsibility that I hope he will one day share), and
the
> gist
> > > > >of what he told me is as follows.
> > > > >
> > > >Aqua regia is a stable mixture of acids that will not spontaneously
> explode
> > > > >at normal temperatures, though a small amount of pressure will
build
> up in
> > > > >its container until any air present is saturated with the acid
> vapours. It
> > > > >should, of course be kept in a glass or plastic container with
screw
> cap,
> > > > >which is capable of withstanding the small build-up of pressure
that
> > > > >occurs. And the general rule for acids is that they should be
stored
> in a
> > > > >cool, dark place; heat increases the pressure, and light may cause
> > > > >photolysis that in turn causes decomposition and the liberation of
> gases.
> > > > >It is also important that the container is clean, to avoid
> contaminants
> > > > >that could catalyse decomposition.
> > >
> > > This is patently wrong and compounds the error in PF No 3.
> > >
> > > To add to the warnings I have found the following at:
> > >
> > > http://www2.umdnj.edu/eohssweb/aiha/accidents/explosion.htm#Two
> > >
> > > Do a page search on "aqua regia" as the pertinent part is about 80%
down
> > > the page. It is from the American Industrial Hygene Association on the
> New
> > > Jersey Medical and Dental College site. It highlights two cases of
aqua
> > > regia explosions. These were not just caps blowing off but violent
> > > explosions shattering the glass bottles with enough force to break
other
> > > nearby bottles. Had someone been in the room and been the subject of
> flying
> > > glass and hot aqua regia spray it could have been very messy.
> > >
> > > The text follows:
> > >
> > > >Two Explosions Involving Aqua Regia (top)
> > > >Key Learning Points
> > > >1. Use a reagent that is milder than aqua regia for cleaning
glassware
> if
> > > >it will suffice.
> > >
> > >
> > >
> > > >2. Do not take aqua regia out of the fume hood in which it was
> prepared,
> > > >and do not store it there either; make only what you need and destroy
> the
> > > >residue. Aqua regia can be destroyed by cautious and careful dilution
> with
> > > >water - talk to your supervisor or your safety office for a detailed
> > > >procedure. If necessary, the solution can then be neutralized and
> disposed
> > > >of in the approved manner.
> > >
> > >
> > >
> > > >3. Never put aqua regia in a closed container or near flammables.
> > >
> > >
> > >
> > > >There have been explosions involving aqua regia ( a mixture of
> > > >hydrochloric acid and nitric acid) reported at two universities. Both
> of
> > > >the incidents took place in chemistry laboratories.
> > >
> > >
> > >
> > > >In the first incident, a graduate student was using aqua regia for
the
> > > >cleaning of NMR tubes. When he was finished, he placed the residues
> (about
> > > >50-60 ml) in a 4 litre waste bottle, capped it tightly and placed it
in
> a
> > > >flammable storage cabinet. Approximately one hour after the bottle
was
> > > >placed in the cabinet, it burst, breaking an adjacent bottle of
> pyridine.
> > > >Luckily, the pyridine did not ignite and other nearby bottles
> containing
> > > >flammable solvents did not become involved. The pyridine leaked onto
> the
> > > >floor, where it dissolved floor tiles and created a lingering bad
> smell.
> > > >The second incident occurred in a fume hood in a synthetic chemistry
> > > >laboratory. A tightly closed waste bottle containing used aqua regia
> > > >exploded, most probably due to pressure buildup inside the bottle.
> > > >Since the sash was not completely closed the broken waste bottle was
> not
> > > >contained. Broken glass as well as some liquid acid waste were thrown
> out
> > > >of the hood. Since nobody was near the hood at that moment, there
were
> no
> > > >injuries. Moreover, a nearby bottle of mercury nitrate waste was also
> > > >broken as well as the secondary container, so that a small spill
(less
> > > >than 1 liter) of liquid acid and solid mercury nitrate occurred
inside
> the
> > > >hood.
> > >
> > >
> > >
> > > >What is aqua regia?
> > > >Aqua regia has been used by chemists for centuries, especially as a
> medium
> > > >for dissolving noble metals but also for other purposes. It is a
> mixture
> > > >of concentrated hydrochloric and nitric acid which forms a powerful
> > > >oxidizing medium. Mixing an oxidizer with organic materials may
result
> in
> > > >a highly exothermic reaction. Even without other materials present, a
> > > >chemical reaction occurs slowly and brown fumes of NO2 can be
observed
> (in
> > > >freshman chemistry terms, nitric acid is reduced and hydrochloric
acid
> is
> > > >oxidized). The activity as a dissolving agent decreases slowly and
so,
> by
> > > >definition, the solution is unstable - it should be used "freshly
> prepared".
> > >
> > >
> > >
> > > >Rules for using aqua regia
> > > >Aqua regia is often used as a substitute for chromic sulfuric acid
> > > >cleaning solutions. However, aqua regia is also corrosive and
strongly
> > > >oxidizing. It is essential for some purposes but should not be used
for
> > > >routine cleaning of glassware. If a milder reagent will suffice avoid
> > > >using aqua regia. Alternatives include ultrasonic baths, alconox or
> > > >similar detergents, Pierce RBS-35 (available from VWR) or similar
> > > >detergents or biodegradable surfactants.
> > >
> > >
> > >
> > > >Be aware that sufficient pressure can build up in a short amount of
> time
> > > >to burst the container, even from a very small volume of aqua regia.
> > >
> > >
> > >
> > > >If it is decided that aqua regia is needed, wear protective clothing
> > > >(goggles, gloves, coat) and work in a clean well-ventilated fume
hood.
> > > >Keep the sash down when reactions are in progress.
> > >
> > >
> > >
> > > >Never take aqua regia out of the hood.
> > >
> > >
> > >
> > > >Prepare it, use it, and destroy any excess in the hood in which it
was
> > > >prepared.
> > >
> > >
> > >
> > > >
> > > >Only prepare the amount of aqua regia you need for immediate use.
Never
> > > >store it and never put it in a closed vessel, since evolved gases
will
> > > >cause a pressure build-up and possible explosion.
> > >
> > >
> > >
> > > >Aqua regia is a strong oxidizer. It is incompatible with organic
> solvents,
> > > >flammables and any reducing agents.
> > >
> > > --Dick Sullivan
> > >
> > >
> > >
> >
> > ---------------------------------------------------------
> > Gordon J. Holtslander Dept. of Biology
> > holtsg@duke.usask.ca 112 Science Place
> > http://duke.usask.ca/~holtsg University of Saskatchewan
> > Tel (306) 966-4433 Saskatoon, Saskatchewan
> > Fax (306) 966-4461 Canada S7N 5E2
> > ---------------------------------------------------------
> >
> >
> >
> >
>
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