Safety with chemicals

On Sat, 16 Apr 2005 12:59:39 +0200, Dada <mutt1917x DeleteThis @yahoo.it> wrote:

....
 >Fixers sold on every store makes air unbreathable, and none consider
 >them dangerous, even if they look like when you smell at them.
....


apr1505 from Lloyd Erlick,

There is absolutely no need to tolerate such materials in the
darkroom. In particular, fixer that bites the nose is unnecessary.

I have written articles on these matters, available on my website.
Look under the 'technical' button in the table of contents.

regards,
--le
________________________________
Lloyd Erlick Portraits, Toronto.
voice: 416-686-0326
email: portrait DeleteThis @heylloyd.com
net: <a style='text-decoration: underline;' href="http://www.heylloyd.com" target="_blank">www.heylloyd.com</a>
________________________________
--<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Safety with chemicals 

On Sat, 16 Apr 2005 07:55:04 -0400, Jean-David Beyer
<jdbeyer RemoveThis @exit109.com> wrote:

 >Dada wrote:
   >> I have bought "Historic Photographic Processes" by Richard
  >> Farber. Reading some parts of it I noticed that in every sensitizing
  >> process is involved one or more dangerous chemicals. Now I ask myself
  >> about the real danger they rappresent. There are a lot of exclamation
  >> marks beside the dangerous ingriedents, but also beside special
  >> operation that require attention to not spoilt results and that have
  >> nothing to do with safety. There are also, about Bichromat Gum warning
  >> about Pigments, telling that some of this could be even cancerogenic.
  >> There are generations of painters that have prepaired by themselves
  >> colours and they all have lived a very long time. Talbot live a long
  >> time too, and it doesn't like it has been killed by silver salts.
  >> Fixers sold on every store makes air unbreathable, and none consider
  >> them dangerous, even if they look like when you smell at them. I would
  >> like to know if someone of you has experience with this operations and
  >> what can tell me about the real dangers of them. Thanks.
 >
 >You might read Chapter 4, Safety In The Darkroom in Richard J. Henry's book,
 >"Controls in Black and White Photography" Second Edition. Another worthwhile
 >book is M. Alice Ottoboni's "The Dose makes the Poison -- A Plain-Language
 >Guide to Toxicology" Second Edition.

Could you tell me mora about it? I don't live in England and is not
really simple for me to find those books. If you could summarize some
of the contents you would help me. Thanks<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Safety with chemicals 

Dada wrote:
 > On Sat, 16 Apr 2005 07:55:04 -0400, Jean-David Beyer
 > <jdbeyer RemoveThis @exit109.com> wrote:
 >
 >
  >>Dada wrote:
  >>
   >>> I have bought "Historic Photographic Processes" by Richard
   >>>Farber. Reading some parts of it I noticed that in every sensitizing
   >>>process is involved one or more dangerous chemicals. Now I ask myself
   >>>about the real danger they rappresent. There are a lot of exclamation
   >>>marks beside the dangerous ingriedents, but also beside special
   >>>operation that require attention to not spoilt results and that have
   >>>nothing to do with safety. There are also, about Bichromat Gum warning
   >>>about Pigments, telling that some of this could be even cancerogenic.
   >>>There are generations of painters that have prepaired by themselves
   >>>colours and they all have lived a very long time. Talbot live a long
   >>>time too, and it doesn't like it has been killed by silver salts.
   >>>Fixers sold on every store makes air unbreathable, and none consider
   >>>them dangerous, even if they look like when you smell at them. I would
   >>>like to know if someone of you has experience with this operations and
   >>>what can tell me about the real dangers of them. Thanks.
  >>
  >>You might read Chapter 4, Safety In The Darkroom in Richard J. Henry's book,
  >>"Controls in Black and White Photography" Second Edition. Another worthwhile
  >>book is M. Alice Ottoboni's "The Dose makes the Poison -- A Plain-Language
  >>Guide to Toxicology" Second Edition.
 >
 >
 > Could you tell me mora about it? I don't live in England and is not
 > really simple for me to find those books. If you could summarize some
 > of the contents you would help me. Thanks

I do not live in England either.

It is really difficult to teach a course in toxicology in only a few words
in an Internet posting even were I a professional toxicologist, which I am not.

Here is my attempt.

USE A LITTLE COMMON SENSE! Now there is nothing so rare as common sense, so
I hope you are one of the elect who have it.

Dr. Henry was an MD who did mainly work in research chemistry. He advocated
not taking an hysterical approach to black and white darkroom safety.

M. Alice Ottoboni, Ph.D., was Staff Toxicologist with the California State
Department of Public Health for over twenty years. Her book is not a course
in toxicology, but it explains the subject in a way that an educated member
of the general public can understand. To do that limited task required her
244 pages. It is already a summary. For me to attempt to summarize her
summary in a few sentences would do it an injustice.

If you care, you will just have to do a little work, perhaps at a good
public or university library. I hope your country has libraries and
universities.

--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ PGP-Key: 9A2FC99A Registered Machine 241939.
/( )\ Shrewsbury, New Jersey <a style='text-decoration: underline;' href="http://counter.li.org" target="_blank">http://counter.li.org</a>
^^-^^ 08:50:00 up 5 days, 2:05, 4 users, load average: 3.45, 3.36, 3.32<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Safety with chemicals 

On Sat, 16 Apr 2005 08:55:12 -0400, Lloyd Erlick <Lloyd at @the-wire.
dot com> wrote:

 >On Sat, 16 Apr 2005 12:59:39 +0200, Dada <mutt1917x.RemoveThis@yahoo.it> wrote:
 >
 >...
  >>Fixers sold on every store makes air unbreathable, and none consider
  >>them dangerous, even if they look like when you smell at them.
 >...
 >
 >
 >apr1505 from Lloyd Erlick,
 >
 >There is absolutely no need to tolerate such materials in the
 >darkroom. In particular, fixer that bites the nose is unnecessary.
 >
Right, when I can I use sodium thiosulfate that doesn't smell, but the
problem is with conservation. I have read that you can't put it in the
bottle after using it, because it will not work the day after. This is
the problem, because now I am trying pinhole photography and I need to
see the result to understund what kind of exposure times are the best
for the camera I have made (times on schedule are not always right),
and to do it everyday, I need to conservate chemicals from day to day.
I would be possible to make a sodium thiosulfate fixer and to add a
component to conserve it, but a component that doesn't smell?<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Safety with chemicals 

Dada <mutt1917x.DeleteThis@yahoo.it> wrote:

  >>
 > Right, when I can I use sodium thiosulfate that doesn't smell, but the
 > problem is with conservation. I have read that you can't put it in the
 > bottle after using it, because it will not work the day after. This is


TF-2 doesn't smell. Well maybe if you pour it up your nose-)

<a style='text-decoration: underline;' href="http://www.jackspcs.com/tf2.htm" target="_blank">http://www.jackspcs.com/tf2.htm</a>

Keeps very well.

Nick<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Safety with chemicals 

On Sat, 16 Apr 2005 16:55:57 +0200, Dada <mutt1917x.DeleteThis@yahoo.it> wrote:

 >On Sat, 16 Apr 2005 08:55:12 -0400, Lloyd Erlick <Lloyd at @the-wire.
 >dot com> wrote:
 >
  >>On Sat, 16 Apr 2005 12:59:39 +0200, Dada <mutt1917x.DeleteThis@yahoo.it> wrote:
  >>
  >>...
   >>>Fixers sold on every store makes air unbreathable, and none consider
   >>>them dangerous, even if they look like when you smell at them.
  >>...
  >>
  >>
  >>apr1505 from Lloyd Erlick,
  >>
  >>There is absolutely no need to tolerate such materials in the
  >>darkroom. In particular, fixer that bites the nose is unnecessary.
  >>
 >Right, when I can I use sodium thiosulfate that doesn't smell, but the
 >problem is with conservation. I have read that you can't put it in the
 >bottle after using it, because it will not work the day after. This is
 >the problem, because now I am trying pinhole photography and I need to
 >see the result to understund what kind of exposure times are the best
 >for the camera I have made (times on schedule are not always right),
 >and to do it everyday, I need to conservate chemicals from day to day.
 >I would be possible to make a sodium thiosulfate fixer and to add a
 >component to conserve it, but a component that doesn't smell?



apr1605 from Lloyd Erlick,

It is very easy to make a sodium thiosulfate fixer that has absolutely
no smell. Ansel Adams published a fixer formula in the Appendix of
"The Print" for a fixer he called 'plain fixer'. It consists of 160
grams anhydrous sodium thiosulfate and about twenty grams of anhydrous
sodium sulfite per liter. It stores as well as any other fixer, and it
has a relatively low capacity so there should be no need to store for
long periods. It is very cheap and easy to prepare. I go on a greater
length in one of the articles on my website.

(In case I have not been descriptive enough, sodium sulfite is an
ingredient often called an 'oxygen scavenger'. It reacts with oxygen
very readily, more so than sodium thiosulfate, and therefore protects
the thiosulfate from oxidation in a fixer solution. The protection
will last for many days or even weeks, hopefully long enough for the
worker to use up the capacity of the fixer.)

regards,
--le
________________________________
Lloyd Erlick Portraits, Toronto.
voice: 416-686-0326
email: portrait.DeleteThis@heylloyd.com
net: <a style='text-decoration: underline;' href="http://www.heylloyd.com" target="_blank">www.heylloyd.com</a>
________________________________
--<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Safety with chemicals 

In article <g6m7j2-154.ln1 DeleteThis @barley.site>,
  Nick Zentena <zentena DeleteThis @stout.hophead.dyndns.org> writes:
 >
 > TF-2 doesn't smell. Well maybe if you pour it up your nose-)
 >
<font color=purple> > <a style='text-decoration: underline;' href="http://www.jackspcs.com/tf2.htm</font" target="_blank">http://www.jackspcs.com/tf2.htm</font</a>>
 >
 > Keeps very well.

Does anybody have experience with Arista Premium Powder (Odorless) Fixer,
or know what it's equivalent to?

<a style='text-decoration: underline;' href="http://www.freestylephoto.biz/sc_prod.php?cat_id=303&pid=595" target="_blank">http://www.freestylephoto.biz/sc_prod.php?cat_id=303&pid=595</a>

According to the MSDS sheet (available from
<a style='text-decoration: underline;' href="http://www.freestylephoto.biz/t_msds_arista.php" target="_blank">http://www.freestylephoto.biz/t_msds_arista.php</a>), it's got sodium
thiosulfate (like the formula to which you referred), sodium acetate, and
sodium metabisulfite.

FWIW, I'm interested because I feel like I've got a slightly sore throat
and a slightly runny nose for a day or so after an enlarging session, so
I'm looking for chemicals that are somewhat less irritating, and the
Arista is the least expensive "odorless" fixer I've seen advertised. (I'm
currently using Dektol, Kodak indicator stop bath, and Kodak fixer.) I
might eventually get into mixing my own stuff, like TF-2, from scratch,
but I'm not quite ready to explore that area. Advice on other developers
and/or stop baths is also appreciated, or if anybody can suggest which of
the chemicals is likely to be causing my mild reaction, I can focus on
that one. Thanks.

--
Rod Smith, rodsmith DeleteThis @rodsbooks.com
<a style='text-decoration: underline;' href="http://www.rodsbooks.com" target="_blank">http://www.rodsbooks.com</a>
Author of books on Linux, FreeBSD, and networking<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Safety with chemicals 

On Sat, 16 Apr 2005 18:02:02 -0000, rodsmith.DeleteThis@nessus.rodsbooks.com (Rod
Smith) wrote:

 >...
 >FWIW, I'm interested because I feel like I've got a slightly sore throat
 >and a slightly runny nose for a day or so after an enlarging session
....


apr1605 from Lloyd Erlick,

This is a good example of why I went on a smell abatement rampage in
my darkroom a few years ago. There is absolutely no reason to tolerate
any such irritation.

In high school I had a chemistry teacher who had grown tired of
teenagers. His attitude had become scornful and snide to the extreme.
He inadvertently told us the reason we should not use fixers that bite
our noses ...

The gas coming out of these fixers is sulfur dioxide. Sulfur dioxide
dissolves readily in water, and our mucous membranes contain plenty of
water. If we inhale sulfur dioxide, it dissolves in the water in our
mucous membranes, which are located in our noses, bronchia and lungs,
and reacts with the water to form sulfurous acid. These locations
contain plenty of oxygen, and sulfurous acid oxidizes readily to form
sulfuric acid. This is why it bites your nose, and I have been unable
to include the appropriate level of snideness; it's a tone of voice, I
guess.

A fixer that contains no acid will not emit sulfur dioxide. It's very
easy and cheap to make fixer from raw materials. I have an article
about it on my website, under the 'technical' heading' in the table of
contents.

regards,
--le
________________________________
Lloyd Erlick Portraits, Toronto.
voice: 416-686-0326
email: portrait.DeleteThis@heylloyd.com
net: <a style='text-decoration: underline;' href="http://www.heylloyd.com" target="_blank">www.heylloyd.com</a>
________________________________
--<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Safety with chemicals 

"Lloyd Erlick" <Lloyd at @the-wire. dot com> wrote in
message news:l3k261lm9auofe9l0b2kem88ei858dvcno@4ax.com...
 > On Sat, 16 Apr 2005 16:55:57 +0200, Dada
 > <mutt1917x.TakeThisOut@yahoo.it> wrote:
 >
  >>On Sat, 16 Apr 2005 08:55:12 -0400, Lloyd Erlick <Lloyd at
  >>@the-wire.
  >>dot com> wrote:
  >>
   >>>On Sat, 16 Apr 2005 12:59:39 +0200, Dada
   >>><mutt1917x.TakeThisOut@yahoo.it> wrote:
   >>>
   >>>...
   >>>>Fixers sold on every store makes air unbreathable, and
   >>>>none consider
   >>>>them dangerous, even if they look like when you smell at
   >>>>them.
   >>>...
   >>>
   >>>
   >>>apr1505 from Lloyd Erlick,
   >>>
   >>>There is absolutely no need to tolerate such materials in
   >>>the
   >>>darkroom. In particular, fixer that bites the nose is
   >>>unnecessary.
   >>>
  >>Right, when I can I use sodium thiosulfate that doesn't
  >>smell, but the
  >>problem is with conservation. I have read that you can't
  >>put it in the
  >>bottle after using it, because it will not work the day
  >>after. This is
  >>the problem, because now I am trying pinhole photography
  >>and I need to
  >>see the result to understund what kind of exposure times
  >>are the best
  >>for the camera I have made (times on schedule are not
  >>always right),
  >>and to do it everyday, I need to conservate chemicals from
  >>day to day.
  >>I would be possible to make a sodium thiosulfate fixer and
  >>to add a
  >>component to conserve it, but a component that doesn't
  >>smell?
 >
 >
 >
 > apr1605 from Lloyd Erlick,
 >
 > It is very easy to make a sodium thiosulfate fixer that
 > has absolutely
 > no smell. Ansel Adams published a fixer formula in the
 > Appendix of
 > "The Print" for a fixer he called 'plain fixer'. It
 > consists of 160
 > grams anhydrous sodium thiosulfate and about twenty grams
 > of anhydrous
 > sodium sulfite per liter. It stores as well as any other
 > fixer, and it
 > has a relatively low capacity so there should be no need
 > to store for
 > long periods. It is very cheap and easy to prepare. I go
 > on a greater
 > length in one of the articles on my website.
 >
 > (In case I have not been descriptive enough, sodium
 > sulfite is an
 > ingredient often called an 'oxygen scavenger'. It reacts
 > with oxygen
 > very readily, more so than sodium thiosulfate, and
 > therefore protects
 > the thiosulfate from oxidation in a fixer solution. The
 > protection
 > will last for many days or even weeks, hopefully long
 > enough for the
 > worker to use up the capacity of the fixer.)
 >
 > regards,
 > --le
 > ________________________________
 > Lloyd Erlick Portraits, Toronto.
 > voice: 416-686-0326
 > email: portrait.TakeThisOut@heylloyd.com
<font color=purple> > net: <a style='text-decoration: underline;' href="http://www.heylloyd.com</font" target="_blank">www.heylloyd.com</font</a>>
 > ________________________________
 > --
The sulfite in fixing baths serves a couple of purposes.
In the usual acid fixing bath it is necessary to prevent the
acid from decomposing the thiosulfate. In a neutral fixing
bath much less sulfite is necessary and there is no
generation of sulfur dioxide gas because of the lack of
acid. Acid fixing baths typically have about 15 grams/liter
of sulfite. A non-acid bath needs no more than about 5
grams/liter although a bit more will help prevent staining
from carried over developer. The acid in fixing baths is
necessary for the hardener. If the hardener is left out the
fixing bath does not need to be acid although the acid has
the advantage of prevent carried over developer from
continuing to be active in the fixer. A fixer made with
either sodium or ammonium thiosulfate (rapid fixer) and
sulfite is quite satisfactory provided a sufficient rinse
between developer and fixing bath is used. A "plain water"
stop bath must be more than just a dip in water, it should
be a short wash to remove as much developer from the
emulsion as possible.
The use of a non hardening fixing bath will result in
greater washing efficiency, a neutral fixing bath in even
better washing efficiency. However, the use of a sulfite
wash aid such as Kodak Hypo Clearing Agent will result in
even faster washing when used with any fixer.


--
---
Richard Knoppow
Los Angeles, CA, USA
dickburk.TakeThisOut@ix.netcom.com<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Safety with chemicals 

"Dada" <mutt1917x RemoveThis @yahoo.it> wrote in message
news:hhr161h43cvc985m9pcmhmv4e2aiip1nqt@4ax.com...
 > I have bought "Historic Photographic Processes" by Richard
 > Farber. Reading some parts of it I noticed that in every
 > sensitizing
 > process is involved one or more dangerous chemicals. Now I
 > ask myself
 > about the real danger they rappresent. There are a lot of
 > exclamation
 > marks beside the dangerous ingriedents, but also beside
 > special
 > operation that require attention to not spoilt results and
 > that have
 > nothing to do with safety. There are also, about Bichromat
 > Gum warning
 > about Pigments, telling that some of this could be even
 > cancerogenic.
 > There are generations of painters that have prepaired by
 > themselves
 > colours and they all have lived a very long time. Talbot
 > live a long
 > time too, and it doesn't like it has been killed by silver
 > salts.
 > Fixers sold on every store makes air unbreathable, and
 > none consider
 > them dangerous, even if they look like when you smell at
 > them. I would
 > like to know if someone of you has experience with this
 > operations and
 > what can tell me about the real dangers of them. Thanks.

There are some chemicals used in photography, especially
some alternative processes, that must be handled with care
and with some knowledge of basic chemical safety.
Processes like Gum Bichromate, Carbon, and others use
Potassium bichromate to sensitize the coating. This material
can cause severe burns so the powder and concentrated
solutions should be kept off the skin. Some chromium
compounds are carcinogenic (valence 6 but not valence 3). In
general substances like bichromate should be handled with
protection by means of nitrile gloves, an apron, a face
mask, and good ventillation.
Most chemicals used in conventional B&W photography are
not dangerous in the amounts and forms used. Prepared or
packaged chemistry is not particularly hazardous but the use
of gloves and a face mask (for powders) are good
precautions.
Fixing baths can emmit sulfur dioxide gas. This has a
sharp odor. It can set off asthma in those sensitive to it.
A non-acid fixing bath will eliminate the odor since it
comes from a reaction between the acid and other
ingredients. The acid is needed only if a hardener is used.
Some are sentive to the odor of Acetic acid, used in stop
baths and some fixing baths. If a non-acid fixer is used an
acid stop bath can not be used, rather a plain water short
wash takes its place. If a conventional fixer is used there
are a number of alternatives to Acetic acid. Citric acid is
odor free. It is not quite compatible with alum hardener but
is perfectly satisfactory for a non hardening acid fixing
bath. Ilford's packaged stop bath is citric acid. There are
other alternatives.
Silver nitrate is hazardous but is not used in many
conventional B&W darkroom processes. It is used mainly in
emulsion making and in some toners.
It is difficult to find reliable information on chemical
safety. Some of the more popular books, especially those
intended for artists, are written by people with
questionable qualifications in toxicology and are full of
errors and exagerations. _The Dose Makes the Poison_ by M.
Alice Ottoboni, as recommended by J-P Beyer in another post
is a good place to start.
MSDS can be misleading because they are _legal_ not
scientific or technical documents, meant mostly to protect
the manufacturer from legal jeapordy, and often discuss the
problems of massive storage or use of the substances they
cover.


--
---
Richard Knoppow
Los Angeles, CA, USA
dickburk RemoveThis @ix.netcom.com<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Safety with chemicals 

Dada wrote:
 >
  > > apr1505 from Lloyd Erlick,
  > >
  > > There is absolutely no need to tolerate such materials in
  > > the darkroom. In particular, fixer that bites the nose
  > > is unnecessary.
  > >
 >
 > Right, when I can, I use sodium thiosulfate that doesn't
 > smell, but the problem is with conservation. I have read
 > that you can't put it in the bottle after using it,
 > because it will not work the day after.
 >

UNADULTERATED S. or A. thiosulfate will do the job.
Neither gives forth any fumes or oder, solid, concentrate,
or working strength. Preservatives and ph modifiers, which
are not needed, are added to all off the shelf fixers.
I use fixer, S. or A., VERY DILUTE, one-shot; use once
then toss. Place enough of the solid or concentrate in the
needed amount of solution. Do a few tests.
S. or A. Thio, I keep a few small bottles on hand. When
needed I add one to make up the solution volume needed.
Doing as I do you will always have fresh fixer and
know that it will fully do the job.
Use off the shelf fixers the same way, VERY DILUTE, one
shot. Oder and fumes will be at a minimum. Dan<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Safety with chemicals 

"Lloyd Erlick" <Lloyd at @the-wire. dot com> wrote

 > There is absolutely no need to tolerate ... fixer
 > that bites the nose...

Some, on the other tong, love the smell of fixer
in the morning.

In either case, the parfume of fixer is not, AFAAK,
harmful.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
To reply, remove spaces: n o lindan at ix . netcom . com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Safety with chemicals 

On Sun, 17 Apr 2005 15:58:30 GMT, "Nicholas O. Lindan" <see RemoveThis @sig.com>
wrote:

 >"Lloyd Erlick" <Lloyd at @the-wire. dot com> wrote
 >
  >> There is absolutely no need to tolerate ... fixer
  >> that bites the nose...
 >
 >Some, on the other tong, love the smell of fixer
 >in the morning.
 >
 >In either case, the parfume of fixer is not, AFAAK,
 >harmful.


apr1705 from Lloyd Erlick,

The perfume of fixer is quite different from the bite.

Plain fix has a very pleasant, distinctive, gentle scent due to sodium
thiosulfate. One must be around it for a while, or lean over and look
for it, to smell it. Like a good perfume! To me, this is the scent of
the darkroom, the smell of photography (along with the smell of a roll
of film and the smell of a newly opened package of paper).

The bite of sulfur dioxide is not the smell of fixer in the morning,
at least not to me.

regards,
--le
________________________________
Lloyd Erlick Portraits, Toronto.
voice: 416-686-0326
email: portrait RemoveThis @heylloyd.com
net: <a style='text-decoration: underline;' href="http://www.heylloyd.com" target="_blank">www.heylloyd.com</a>
________________________________
--<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Safety with chemicals