Elemental selenium

Wilco Oelen wrote:
Hello,

I obtained a small amount of elemental selenium (a very fine grey/black
powder) and intend to use it for preparing a Selenium toner. I did a
search on its properties and came across some discussions on selenium
toxicity. Some people were really afraid of it, but I think much of the
discussion is based on hysteria, people being afraid of everything
which is chemical. However, the discussions (and also the MSDS) have
triggered me and made me cautious.

Now I want to ask you, what is its _real_ toxicity? Please no hysteria
on chemistry, but real advice. I have experience with quite some toxic
chemicals like ammonium dichromate, thiourea, sulfides, vanadium
compunds, and many other metal salts. Before I use the selenium I want
to assess the risks of it, based on your comments. A comparison with
other toxic compounds would be useful for me, i.e. how does it compare
to using dichromates or something like that.

Thanks for your reply,

I would ignore the issue by using pre-mixed toner, such as Kodak's Rapid
Selenium Toner. I assume you would not drink it, etc.

The main problem with making your own is that the powder is easy to get
into the air and inhaled. If you are a trained chemist or chemical
technician and know how to control powders (most photochemicals are not
powders, but crushed crystals), you can probably handle it OK. But I am
not, so I would not.

Also, if it is like powdered boric acid, it may be tough to get it into
solution in the first place.

--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 241939.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 16:45:00 up 7 days, 2:26, 4 users, load average: 0.15, 0.17, 0.11

Wilco Oelen wrote:
Hello,

I obtained a small amount of elemental selenium (a very fine grey/black
powder) and intend to use it for preparing a Selenium toner. I did a
search on its properties and came across some discussions on selenium
toxicity. Some people were really afraid of it, but I think much of the
discussion is based on hysteria, people being afraid of everything
which is chemical. However, the discussions (and also the MSDS) have
triggered me and made me cautious.

Now I want to ask you, what is its _real_ toxicity? Please no hysteria
on chemistry, but real advice. I have experience with quite some toxic
chemicals like ammonium dichromate, thiourea, sulfides, vanadium
compunds, and many other metal salts. Before I use the selenium I want
to assess the risks of it, based on your comments. A comparison with
other toxic compounds would be useful for me, i.e. how does it compare
to using dichromates or something like that.

Thanks for your reply,

I would ignore the issue by using pre-mixed toner, such as Kodak's Rapid
Selenium Toner. I assume you would not drink it, etc.

The main problem with making your own is that the powder is easy to get
into the air and inhaled. If you are a trained chemist or chemical
technician and know how to control powders (most photochemicals are not
powders, but crushed crystals), you can probably handle it OK. But I am
not, so I would not.

Also, if it is like powdered boric acid, it may be tough to get it into
solution in the first place.

--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 241939.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 16:45:00 up 7 days, 2:26, 4 users, load average: 0.15, 0.17, 0.11

"Wilco Oelen" wrote in message
om...

Now I want to ask you, what is its _real_ toxicity? Please no hysteria
on chemistry, but real advice. [...]

It's red powder, correct? (Making sure you have real elemental selenium
powder). It's practically harmless as-is. Now what you make from it is
another matter. What else is going into your brew? Selenium compounds such
as Hydrogen Selenide is quite deadly.

Here are three formulas I found for making selenium toners. Sorry for the
tossed-salad formatting once they were copied into this message.

--------

Adam's Toner Formula
Part A: boiling water 250 ml.
sodium sulfide crystals 60 gm.
selenium metal powder 5 gm.

Part B: water (125 deg. F.) 3 liters
sodium thiosulfate 660 gm.

Add A to B, then dissolve sodium bisulfate 210 gm. Add water to make 4
liters total.
Presoak print in Kodalk for 15 to 30 sec., use toner straight.

---------


Rapid Selenium Toner (formula source unknown - found on my computer from a
long deceased project)
Part A: sodium sulfide 60 gm.
water (hot?) 500 ml.
selenium metal powder 2 gm.

Part B: ammonium chloride 20 gm.
water 500 ml.

Add B to A when A is cool. Solution will keep indefinitely. Dilute for
desired color.

---------


IT-3 Two-bath Selenium Redish-Brown Toner (from Barfen Darkroom Chemicals
Handbook, Dr.
Shaul Tal editor, 1982, Restem LTD, Tel Aviv, Israel)
Part A: Pot. Ferricyanide 100 gm
Pot. Bromide 100gm
Water 1 liter

Part B: Sodium sulfide 104 gm
Selenium powder 6.8 gm
Water 1 liter
Bleach in A (1+9); wash;tone in B (1+10) for 2-3 min.

-----

Bill Schneider

Here are three formulas I found for making selenium toners. Sorry for the
tossed-salad formatting once they were copied into this message.

--------

Adam's Toner Formula
Part A: boiling water 250 ml.
sodium sulfide crystals 60 gm.
selenium metal powder 5 gm.

Part B: water (125 deg. F.) 3 liters
sodium thiosulfate 660 gm.

Add A to B, then dissolve sodium bisulfate 210 gm. Add water to make 4
liters total.
Presoak print in Kodalk for 15 to 30 sec., use toner straight.

---------


Rapid Selenium Toner (formula source unknown - found on my computer from a
long deceased project)
Part A: sodium sulfide 60 gm.
water (hot?) 500 ml.
selenium metal powder 2 gm.

Part B: ammonium chloride 20 gm.
water 500 ml.

Add B to A when A is cool. Solution will keep indefinitely. Dilute for
desired color.

---------


IT-3 Two-bath Selenium Redish-Brown Toner (from Barfen Darkroom Chemicals
Handbook, Dr.
Shaul Tal editor, 1982, Restem LTD, Tel Aviv, Israel)
Part A: Pot. Ferricyanide 100 gm
Pot. Bromide 100gm
Water 1 liter

Part B: Sodium sulfide 104 gm
Selenium powder 6.8 gm
Water 1 liter
Bleach in A (1+9); wash;tone in B (1+10) for 2-3 min.

-----

Bill Schneider

William Schneider wrote:

Here are three formulas I found for making selenium toners. Sorry for the
tossed-salad formatting once they were copied into this message.

--------

Adam's Toner Formula
Part A: boiling water 250 ml.
sodium sulfide crystals 60 gm.
selenium metal powder 5 gm.

Part B: water (125 deg. F.) 3 liters
sodium thiosulfate 660 gm.

Add A to B, then dissolve sodium bisulfate 210 gm. Add water to make 4
liters total.
Presoak print in Kodalk for 15 to 30 sec., use toner straight.

---------

Rapid Selenium Toner (formula source unknown - found on my computer from a
long deceased project)
Part A: sodium sulfide 60 gm.
water (hot?) 500 ml.
selenium metal powder 2 gm.

Part B: ammonium chloride 20 gm.
water 500 ml.

Add B to A when A is cool. Solution will keep indefinitely. Dilute for
desired color.

---------

IT-3 Two-bath Selenium Redish-Brown Toner (from Barfen Darkroom Chemicals
Handbook, Dr.
Shaul Tal editor, 1982, Restem LTD, Tel Aviv, Israel)
Part A: Pot. Ferricyanide 100 gm
Pot. Bromide 100gm
Water 1 liter

Part B: Sodium sulfide 104 gm
Selenium powder 6.8 gm
Water 1 liter
Bleach in A (1+9); wash;tone in B (1+10) for 2-3 min.

-----

Bill Schneider

You might also try Selsun Blue shampoo as the second part of the two step
method.

William Schneider wrote:

Here are three formulas I found for making selenium toners. Sorry for the
tossed-salad formatting once they were copied into this message.

--------

Adam's Toner Formula
Part A: boiling water 250 ml.
sodium sulfide crystals 60 gm.
selenium metal powder 5 gm.

Part B: water (125 deg. F.) 3 liters
sodium thiosulfate 660 gm.

Add A to B, then dissolve sodium bisulfate 210 gm. Add water to make 4
liters total.
Presoak print in Kodalk for 15 to 30 sec., use toner straight.

---------

Rapid Selenium Toner (formula source unknown - found on my computer from a
long deceased project)
Part A: sodium sulfide 60 gm.
water (hot?) 500 ml.
selenium metal powder 2 gm.

Part B: ammonium chloride 20 gm.
water 500 ml.

Add B to A when A is cool. Solution will keep indefinitely. Dilute for
desired color.

---------

IT-3 Two-bath Selenium Redish-Brown Toner (from Barfen Darkroom Chemicals
Handbook, Dr.
Shaul Tal editor, 1982, Restem LTD, Tel Aviv, Israel)
Part A: Pot. Ferricyanide 100 gm
Pot. Bromide 100gm
Water 1 liter

Part B: Sodium sulfide 104 gm
Selenium powder 6.8 gm
Water 1 liter
Bleach in A (1+9); wash;tone in B (1+10) for 2-3 min.

-----

Bill Schneider

You might also try Selsun Blue shampoo as the second part of the two step
method.

In article ,
(Dan Quinn) wrote:

(Wilco Oelen) wrote

I did a search on its properties and came across some
discussions on selenium toxicity.


There is at least one good post this NG dealing with the makeing
of toner using elemental selenium. Did you find that post? Dan

No, but I believe Tim Rudman gives a recipe in his wonderful toning book.

--

-tony

http://www.shapesandshadows.com

In article ,
(Dan Quinn) wrote:

(Wilco Oelen) wrote

I did a search on its properties and came across some
discussions on selenium toxicity.


There is at least one good post this NG dealing with the makeing
of toner using elemental selenium. Did you find that post? Dan

No, but I believe Tim Rudman gives a recipe in his wonderful toning book.

--

-tony

http://www.shapesandshadows.com

"Wilco Oelen" wrote in message
om...
Hello,

I obtained a small amount of elemental selenium (a very
fine
grey/black powder) and intend to use it for preparing a
Selenium
toner. I did a search on its properties and came across
some
discussions on selenium toxicity. Some people were really
afraid of
it, but I think much of the discussion is based on
hysteria, people
being afraid of everything which is chemical. However, the
discussions
(and also the MSDS) have triggered me and made me
cautious.

Now I want to ask you, what is its _real_ toxicity? Please
no hysteria
on chemistry, but real advice. I have experience with
quite some toxic
chemicals like ammonium dichromate, thiourea, sulfides,
vanadium
compunds, and many other metal salts. Before I use the
selenium I want
to assess the risks of it, based on your comments. A
comparison with
other toxic compounds would be useful for me, i.e. how
does it compare
to using dichromates or something like that.

Thanks for your reply,

Wilco

Elemental Selenium is toxic but much less so than
Selenium compounds. The main danger is inhalation of the
powder. Selenium, contrary to some conventional wisdom, is
NOT a metal, but has some characteristics of a metal. It is
NOT stored in the body and is not a "heavy metal" like lead
or Mercury.
Use great care in handling the powder to avoid getting
it airborne. Wear an effective dustmask.
Powdered Selenium dissolves with great difficulty, the
solutions must be boiled for some time. At least one patent
for a Selenium toner requires boiling for 24 hours!
Ansel Adams has a formula for a Selenium toner in the
early edition of his book _The Print_.
Sodium sulfide is used in most of the toners to help the
Selenium to dissolve. Such toners are probably combination
toners with some sulfiding of the image. The color may be a
little different than a pure Selenium toner like Kodak Rapid
Selenium Toner but the images should be well protected.


--
---
Richard Knoppow
Los Angeles, CA, USA