Thiocyanate

Photo Engineer · Jul 22, 2006

Many times, there has been rather heated debate over the use of thiocyanate salts in photographic processing solutions.

One, in particluar, is the use in fixers.

I would like to let you know that I just found out that it is used in some brands of toothpaste. BIOTENE toothpaste for an example, contains potassium thiocyante.

Just FYI, this reaffirms my previous contentions that thiocyanate salts are not unduly toxic.

PE

Donald Miller · Jul 22, 2006

Could this be the missing ingredient in the hand coating holy grail? Buy lots of toothpaste everyone.

Donald Qualls · Jul 22, 2006

Photo Engineer said:
I would like to let you know that I just found out that it is used in some brands of toothpaste. BIOTENE toothpaste for an example, contains potassium thiocyante.

Just FYI, this reaffirms my previous contentions that thiocyanate salts are not unduly toxic.

Based on this MSDS, I have to say it's rather surprising to see thiocyanates in toothpaste, though the LD50 is high enough that a few milligrams in an inch-long ribbon likely wouldn't have much effect. I see it listed as an inactive ingredient, and well down the list (just above the blue dye), where I'm used to seeing preservatives. I wonder what its purpose is in that formulation?

Still, based on the MSDS, I wouldn't want to use it in solutions I'd put my hands in (yeah, I know, we're told we shouldn't put our hands in any photo chemicals these days, but the powder on latex gloves is pretty nasty and latex isn't impervious to everything anyway); it's specifically noted as an irritant.

Kobin · Jul 22, 2006

Use powderless nitrile, Donald. The chance of synthesizing to the non organic rubber is much smaller. I get them from an Amazon store, 3 -100 count boxes for less than $40. I used to buy 50 count boxes at Home Depot or Lowes for $8.50, but I haven't found any there for months. I suppose too many meth lab guys were buying them. Nitrile also resists chemical migration better than latex.

I use Biotene mouthwash; I wonder if it has-- It does! Pot Thiocynate, just in front of the natural enzymes.

K.

blaze-on · Jul 23, 2006

Kobin said:
Use powderless nitrile, Donald. The chance of synthesizing to the non organic rubber is much smaller. I get them from an Amazon store, 3 -100 count boxes for less than $40. I used to buy 50 count boxes at Home Depot or Lowes for $8.50, but I haven't found any there for months. I suppose too many meth lab guys were buying them. Nitrile also resists chemical migration better than latex.

I use Biotene mouthwash; I wonder if it has-- It does! Pot Thiocynate, just in front of the natural enzymes.

K.

I just ordered two 100 count boxes of Nitrile (powderless) from Dead Link Removed
for $5.53 a box...and free shipping through August 31

Kobin · Jul 23, 2006

Thanks for the site, blaze-on. Great price.

K.

pelerin · Jul 25, 2006

Photo Engineer said:
Many times, there has been rather heated debate over the use of thiocyanate salts in photographic processing solutions.

One, in particluar, is the use in fixers.

I would like to let you know that I just found out that it is used in some brands of toothpaste. BIOTENE toothpaste for an example, contains potassium thiocyante.

Just FYI, this reaffirms my previous contentions that thiocyanate salts are not unduly toxic.

PE

PE,
I understand Thiocyanate is used as an additive in reversal developers to keep the highlights clean. Could it be used in small amounts in Paper developer (replacing some or all of the restrainer) to gain clean whites w/out the change in printing speed associated with e.g., Benzotriazole.
Celac.

Photo Engineer · Jul 25, 2006

pelerin said:
PE,
I understand Thiocyanate is used as an additive in reversal developers to keep the highlights clean. Could it be used in small amounts in Paper developer (replacing some or all of the restrainer) to gain clean whites w/out the change in printing speed associated with e.g., Benzotriazole.
Celac.

Not as far as I know.

And remember that reversal processing and papers are both far from negative processing and film. They are four different subjects.

PE

Gerald Koch · Jul 26, 2006

When thiocyanate is used in reversal processing its purpose is not that of an antifoggant but as a silver halide solvent.

Years ago thiocyanate was added in small amounts to paper developers but the intent was to obtain richer blacks. I have no idea how it would effect modern papers.

Wigwam Jones · Jul 26, 2006

Donald Qualls said:
Based on this MSDS, I have to say it's rather surprising to see thiocyanates in toothpaste, though the LD50 is high enough that a few milligrams in an inch-long ribbon likely wouldn't have much effect. I see it listed as an inactive ingredient, and well down the list (just above the blue dye), where I'm used to seeing preservatives. I wonder what its purpose is in that formulation?

Apparently useful to fight gingivitis?

http://www.ncbi.nlm.nih.gov/entrez/...ve&db=PubMed&list_uids=12492909&dopt=Abstract

Donald Qualls · Jul 26, 2006

Re: thiocyanate in toothpaste

Wigwam Jones said:
Apparently useful to fight gingivitis?

http://www.ncbi.nlm.nih.gov/entrez/...ve&db=PubMed&list_uids=12492909&dopt=Abstract

Possibly, but if that's why it's there, shouldn't it be listed in "active ingredients" instead of "inactive"?

Wigwam Jones · Jul 26, 2006

Donald Qualls said:
Re: thiocyanate in toothpaste

Possibly, but if that's why it's there, shouldn't it be listed in "active ingredients" instead of "inactive"?

You got me. Are added vitamins listed an 'active ingredient' in breakfast cereal?

As I understand it, an 'active ingredient' is almost literally the 'magic part' of the compound. Perhaps the FDA must rule that it is playing a pharmaceutical role before they can list it as such. Or, it may be listed as inactive because it does not clean teeth as such, but provides some other reputed benefit instead (gum health).

Just some guesses. I really have no idea.

ZorkiKat · Jul 27, 2006

Speaking of thiocyanates, is there still signficance today (with current emulsions) 1930s "fine grain" developers like DK20?

Jay

don sigl · Jul 27, 2006

blaze-on said:
I just ordered two 100 count boxes of Nitrile (powderless) from Dead Link Removed
for $5.53 a box...and free shipping through August 31

This link is not working. Anybody else checked it?

Wigwam Jones · Jul 27, 2006

don sigl said:
This link is not working. Anybody else checked it?

http://www.dontheglove.com

The link posted appears to have a period between www and dontheglove.com, but in reality, it doesn't. This should work.

Gerald Koch · Jul 27, 2006

ZorkiKat said:
Speaking of thiocyanates, is there still signficance today (with current emulsions) 1930s "fine grain" developers like DK20?

No, they are apt to cause dichroic fog with today's emulsions.

Photo Engineer · Jul 27, 2006

The only medical use I could find reference to is as a hypotensive.

PE

Thiocyanate

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