No More Pure Ammonia In Canada

fgorga · May 19, 2021

DMJ said:
I use the recipe from Hirsch's book Photographic possibilities:
1L water (20C)
Sodium thiosulfate 50g
Household ammonia (plain) 12ml

I think household ammonia is 5 to 10 percent ammonium hydroxide (NH3) in water and plain means that there shouldn't be any detergents added? Available in the US in hardware stores, supermarkets and Amazon.

The very names of household ammonia:

https://en.wikipedia.org/wiki/Ammonia_solution

Is the ammonia necessary? The recipe for van dykes calls for sodium thiosulfate only, 6 minutes.

Let's get the chemistry correct... ammonia (NH3) is a poisonous gas.

What we are talking about here is 'household ammonia', a solution of ammonium hydroxide (NH4+ OH-). Ammonium hydroxide is produced when you bubble gaseous ammonia into water.

As for the designation 'plain' with regard to household ammonia, you are correct. The 'plain' indicates no detergents or other additives.

Is the household ammonia necessary? Not really. However, it greatly increases the speed of fixing. We are talking 1-2 min vs. the 6 you cite. (I use 'plain old' hypo myself for salted-paper; two trays, 4 min each.)

fgorga · May 19, 2021

Two23 said:
Can you not remove water from the 6% strength to get what you want?

Kent in SD

In principle the answer to your question is "yes".

BUT, and that is a big capitalized BUT!!! , this is not simple or easy.

The simple and easy fix is to just use a larger volume of the more dilute solution and (if necessary) reduce the volume of water somewhere else in the recipe as I described else where in this thread.

fgorga · May 19, 2021

Bronson Dugnutt said:
The ammonium ions are the important bit; I would think that NH4OH could substitute for NH4Cl in a rapid fixer formula if the impact on pH of the hydroxide is accounted for (and vica versa presuming the chloride is benign to kallitype).

As an aside, is the new restriction a result of the proposed changes to Canada's CEPA law?

I agree... the ammonium is the important component here.

Ammonium (NH4+ in aqueous solution is in equilibrium with ammonia (NH3). The ammonia forms complexes with the silver ions that are much more soluble in water than un-complexed silver. This is the basis for "rapid fixing".

As for the ammonium chloride vs. hydroxide issue, I would guess that fixer made with the hydroxide is probably somewhat more efficient than the chloride. The hydroxide solution will have a higher pH than the chloride solution and thus the amount of active species, i.e. the NH3, in the solution will also be somewhat higher.

mshchem · May 20, 2021

Walmart, Menards, other markets still sell "household ammonia" . My Mom would mix up her own, window washing, and general cleaner, I can still smell that stuff. Household Ammonia is a dilute solution of the powerful dangerous lab and industrial chemical, Ammonium hydroxide. This is seriously dangerous stuff..
Here's what Walmart has

Ces1um · May 20, 2021

Andrew O'Neill said:
I ran out of it when I was making kallitype fixer. I've used this fixer (25g sodium thiosulfate Anhyrdrous; 50ml ammonia) for many years. No one has it anymore as it's illegal to sell here, according to the store clerk. Oh well.... I mixed up one that I used to use (Sandy King's) and it'll do. I just appreciated the convenience of the ammonia based rapid fix, and its one minute fixing time. What are others using to fix their kallitypes?

AWESOME Products La's Totally Awesome Pure Ammonia, 64 oz: Amazon.ca: Home & Kitchen

Would this work? I doesn't say that it's diluted in any way on the label from what I can tell.

grain elevator · May 20, 2021

Confusing stuff. I've never heard of any household use of ammonium hydroxide whatsoever. Is that a North American germophobe thing?
There was a recent thread about the need for a bit of sulfite in fixer, is that no issue here?

nmp · May 20, 2021

Ces1um said:
AWESOME Products La's Totally Awesome Pure Ammonia, 64 oz: Amazon.ca: Home & Kitchen

Would this work? I doesn't say that it's diluted in any way on the label from what I can tell.

With that price I would call it Awesome too....

In any case, I strongly suggest to buy a bottle that has the concentration spelled out on the label or on a MSDS so you have a reference for the next time. There are a lot of variations from brand to brand. For example, the Walmart Great Value ammonia linked above is only 2% (it's not on the bottle) that would be too low:

http://msds.walmartstores.com/clien...HazdocumentKey=undefined&MSDS=0&subformat=NAM

:Niranjan.

AgX · May 20, 2021

grain elevator said:
Confusing stuff. I've never heard of any household use of ammonium hydroxide whatsoever. Is that a North American germophobe thing?

Maybe you are just too young to know. Likely there are also regional aspects. I remember the smell of Ammonia and of Eau de Javel even when they cleaned the stoops in Flanders.

fgorga · May 20, 2021

Ces1um said:
AWESOME Products La's Totally Awesome Pure Ammonia, 64 oz: Amazon.ca: Home & Kitchen

Would this work? I doesn't say that it's diluted in any way on the label from what I can tell.

This is an example of the plain old household ammonia that we have been talking about. It is "pure" only in the sense that it contains no detergent. It is, in reality, a solution of ammonium hydroxide that is sold as a consumer product which is commonly, but chemically incorrectly, called "ammonia ".

You will not find pure (in the chemical sense) ammonia in a plastic bottle anywhere. Pure ammonia is a gas. It comes in steel cylinders under high pressure. It is quite toxic.

AgX · May 20, 2021

fgorga said:
It is, in reality, a solution of ammonium hydroxide that is sold as a consumer product which is commonly, but chemically incorrectly, called "ammonia ".

Even the term Ammonium Hydroxide is debatable, actually it is a physical solution of Hydrogen nitride (NH3) (Ammonia) in water, which then produces also Ammonium Hydroxide (NH4OH) in chemical solution, with which it is in equilibrium.

The german term for the aqueous solution is in translation Ammoniawater, but common on bottles you just see Ammonia.

nmp · May 20, 2021

fgorga said:
I agree... the ammonium is the important component here.

Ammonium (NH4+ in aqueous solution is in equilibrium with ammonia (NH3). The ammonia forms complexes with the silver ions that are much more soluble in water than un-complexed silver. This is the basis for "rapid fixing".

As for the ammonium chloride vs. hydroxide issue, I would guess that fixer made with the hydroxide is probably somewhat more efficient than the chloride. The hydroxide solution will have a higher pH than the chloride solution and thus the amount of active species, i.e. the NH3, in the solution will also be somewhat higher.

I am having trouble understanding the role of ammonia in addition to making the fixer alkaline so as to reduce what Christopher James calls bleach-back. In the book (p254, 2nd edition,) he says to use either sodium carbonate (which is what I do for my salt prints and POP) or ammonia but makes no distinction with regards to speed of the fixer. The diy version of the so-called rapid fixer that I can find referenced use some form of ammonium salt such as ammonium chloride, sulfate, acetate etc as a rough substitute for actual ammonium thiosulfate. For example:

https://www.photrio.com/forum/threads/rapid-fixer-without-ammonium-thiosulfate.102211/

https://www.photrio.com/forum/threads/ammonium-hypo-from-sodium-hypo-and-ammonium-chloride.168053/

I am not disputing anything here (I am not qualified,) just wondering if there is any benefit to using ammonia instead of sodium carbonate which is much more controllable and convenient without having to deal with a pungent smell.

:Niranjan.

fgorga · May 20, 2021

nmp said:
I am having trouble understanding the role of ammonia in addition to making the fixer alkaline so as to reduce what Christopher James calls bleach-back. In the book (p254, 2nd edition,) he says to use either sodium carbonate (which is what I do for my salt prints and POP) or ammonia but makes no distinction with regards to speed of the fixer. The diy version of the so-called rapid fixer that I can find referenced use some form of ammonium salt such as ammonium chloride, sulfate, acetate etc as a rough substitute for actual ammonium thiosulfate. For example:

https://www.photrio.com/forum/threads/rapid-fixer-without-ammonium-thiosulfate.102211/

https://www.photrio.com/forum/threads/ammonium-hypo-from-sodium-hypo-and-ammonium-chloride.168053/

I am not disputing anything here (I am not qualified,) just wondering if there is any benefit to using ammonia instead of sodium carbonate which is much more controllable and convenient without having to deal with a pungent smell.

:Niranjan.

I think that there are two things to consider in this regard, the first is the pH. My understanding is that keeping the fixer alkaline increases its stability. In that regard either ammonium hydroxide or sodium carbonate will work.

The second consideration is the speed of fixing. In this context, the two compounds are different. Only the ammonium compound will give the 'rapid' fixing. See my post above for that mechanism.

Personally, I'm with you in wanting to avoid the odor. I use sodium carbonate in my fixer for salted-paper prints.

As far as all of the various mixtures mentioned in the posts you cited, it is important remember that we are dealing with aqueous solution and ionic compounds (salts). When you dissolve a compound such as sodium carbonate in water, you don't have sodium carbonate any more, you have sodium ions and carbonate ions. If you add another compound to the solution you are just adding more and/or different ions... often in these mixtures, most of the compounds are spectators, just hanging around and not participating in the desired chemistry.

fgorga · May 20, 2021

AgX said:
Even the term Ammonium Hydroxide is debatable, actually it is a physical solution of Hydrogen nitride (NH3) (Ammonia) in water, which then produces also Ammonium Hydroxide (NH4OH) in chemical solution, with which it is in equilibrium.

The german term for the aqueous solution is in translation Ammoniawater, but common on bottles you just see Ammonia.

The designation 'hydrogen nitride' is not chemically correct... nitride is an ion, a nitrogen atom with a charge of minus three. Thus the term hydrogen nitride implies an ionic compound. Ammonia (NH3) is not ionic, the bonding is covalent.

Additionally, the term ammonium hydroxide is not 'debatable ', at least among chemists. When you dissolve ammonia in water, the two compounds react to give ammonium ions and hydroxide ions, i.e. ammonium hydroxide.

You are correct though in saying that the ammonium ion is in equilibrium with ammonia. This is want gives these solutions their distinctive odor. The balance between ammonium and ammonia is determined by the pH, the lower the pH the more the balance shifts towards ammonium. The converse is also true.

AgX · May 20, 2021

fgorga said:
The designation 'hydrogen nitride' is not chemically correct... nitride is an ion, a nitrogen atom with a charge of minus three. Thus the term hydrogen nitride implies an ionic compound. Ammonia (NH3) is not ionic, the bonding is covalent.

Well, Nitride designates not an ion, but a whole molecule containing N-3. Molecules that can be either ionic as Li3N or rather covalent as Al3N.

The term Hydrogen Nitride you will find at english Wikipedia (Ammonia) and even explicetely at german Wikipedia (Nitride).

But I admit chemical Terminology is tricky and I am the least to know and Wikipedia can be erroneous too, but I got nothing better at hand. (The terminology I was trained with is completely outdated meanwhile.)

Tom Kershaw · May 20, 2021

I've just had a look at the household ammonia I have in my darkroom and the percentage is listed as 9.5% 'ammonia solution'.

AgX · May 20, 2021

The household grade seems to vary between 6% and 10%, depending on supplier

Andrew O'Neill · May 20, 2021

mshchem said:
Walmart, Menards, other markets still sell "household ammonia" . My Mom would mix up her own, window washing, and general cleaner, I can still smell that stuff. Household Ammonia is a dilute solution of the powerful dangerous lab and industrial chemical, Ammonium hydroxide. This is seriously dangerous stuff..
Here's what Walmart has
View attachment 274890

Not in Canada anymore.

Tom Kershaw · May 20, 2021

I don't have need for it at the moment but 33% solution appears to be available on the open market in the UK:
https://www.ebay.co.uk/itm/163152977932?hash=item25fcace00c:g:sG0AAOSwwpdW2YS3

Andrew O'Neill · May 20, 2021

nmp said:
I am having trouble understanding the role of ammonia in addition to making the fixer alkaline so as to reduce what Christopher James calls bleach-back. In the book (p254, 2nd edition,) he says to use either sodium carbonate (which is what I do for my salt prints and POP) or ammonia but makes no distinction with regards to speed of the fixer. The diy version of the so-called rapid fixer that I can find referenced use some form of ammonium salt such as ammonium chloride, sulfate, acetate etc as a rough substitute for actual ammonium thiosulfate. For example:

https://www.photrio.com/forum/threads/rapid-fixer-without-ammonium-thiosulfate.102211/

https://www.photrio.com/forum/threads/ammonium-hypo-from-sodium-hypo-and-ammonium-chloride.168053/

I am not disputing anything here (I am not qualified,) just wondering if there is any benefit to using ammonia instead of sodium carbonate which is much more controllable and convenient without having to deal with a pungent smell.

:Niranjan.

The smell doesn't bother me. Good air circulation. Fix time of one minute. How long do you fix with the carbonate?

nmp · May 20, 2021

fgorga said:
The second consideration is the speed of fixing. In this context, the two compounds are different. Only the ammonium compound will give the 'rapid' fixing. See my post above for that mechanism.

That's the thing. If it was an all-ammonium compound i.e. ammonium thiosulfate, this would be true. But in this case, when you add ammonium hydroxide to sodium thiosulfate, sodium ions are still there dominating the the multistep complexation with silver halide and thiosulfate ions. To what extent, NH4+ stops being a spectator and getting in on the action is what my question is.

If there was a significant effect on speed by just adding household ammonia, why was that not a standard and why trying to use a more expensive ammonium thiosulfate to make rapid fixers such as TF-4 or TF-3?

Anyway, this is now become an academic discussion - far from Andrew's simple question in the OP. Thanks for indulging me.

:Niranjan.

nmp · May 20, 2021

Andrew O'Neill said:
The smell doesn't bother me. Good air circulation. Fix time of one minute. How long do you fix with the carbonate?

I don't have experience with kallitype or VDB - only with salt prints and POP. My fixing is 5 minutes with fresh one-time use of (15% Na thiosulfate + 0.2% Na carbonate.) The siderotypes are easier, as I understand, to fix since the silver is in the form of soluble silver nitrate most of which comes out in the rinsing and developing before hand and not silver halide embedded in the fibers of the paper as is in the case of salt prints.

:Niranjan.

lantau · May 22, 2021

AgX said:
Well, Nitride designates not an ion, but a whole molecule containing N-3. Molecules that can be either ionic as Li3N or rather covalent as Al3N.

The term Hydrogen Nitride you will find at english Wikipedia (Ammonia) and even explicetely at german Wikipedia (Nitride).

But I admit chemical Terminology is tricky and I am the least to know and Wikipedia can be erroneous too, but I got nothing better at hand. (The terminology I was trained with is completely outdated meanwhile.)

In Ammonia, Nitrogen is considered to formally have Oxidation State +III. So it is a hydride, if anything. Like Hydrocarbones are Alkanes, Ammonia is the simplest Azan. You may have heard of Boranes (BH4, B2H6,etc), Alanes (AlH3) and Silanes (SiH4, Si2H6).

Ammonia (gas) is highly soluble in Water (702L at 20°C, a 35% solution). And with Ammonia being a weak base, the aqueous solution is mostly dissolved NH3 (as a hydrate), indeed, and a small amount of dissociated Ammonium hydroxide (less than 1%).

AgX · May 22, 2021

The Nitrogen in Ammonia has the oxidation number -III.

lantau · May 23, 2021

AgX said:
The Nitrogen in Ammonia has the oxidation number -III.

Sorry, I should not have left out 'formally'. In nomenclature the convention is that elements from maingroup VI and higher are elektronegative enough to have hydrogen as a positive partner. So for nitrogen, formally, N is considered to be the positively charged partner and the hydrogen is considered to be the hydride.

And then there is the newer nomenclature of Azane for Ammonia, diazane for Hydrazin, etc, which does not rely on that fiction.

The first nomenclature should be in your old text book, if you still have your Hollemann.

AgX · May 23, 2021

I guess I am not the only one that finds that all very confusing... But as they say: there is life-long learning.

No More Pure Ammonia In Canada

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