a few citiric acid questions

CMoore · Oct 9, 2017

Not trying to put one of our sponsors on the spot, but.........
1. For making a Stop Bath..... Is there any "practical" difference between what is available on Amazon (food grade/non-gmo) and what is sold by Photographers Formulary.?

2. This warning form the PF website.....
6.2
Environmental precautions
Do not let product enter drains
.......I assume are they talking about Not Dumping the pure powder. There should be no problem with dumping a Citric Acid stop bath.?

Thank You

adelorenzo · Oct 9, 2017

No difference AFAIK. I bought 25 lbs of the food grade stuff for about $75 shipped a few years ago. I don't bother measuring it too accurately, I have a little plastic scoop in the jar that I know roughly how much I holds.

Given that citric acid is a food ingredient I cant imagine how it would harm anything. I certainly pour it down the drain.

trendland · Oct 9, 2017

CMoore said:
Not trying to put one of our sponsors on the spot, but.........
1. For making a Stop Bath..... Is there any "practical" difference between what is available on Amazon (food grade/non-gmo) and what is sold by Photographers Formulary.?

2. This warning form the PF website.....
6.2
Environmental precautions
Do not let product enter drains
.......I assume are they talking about Not Dumping the pure powder. There should be no problem with dumping a Citric Acid stop bath.?

Thank You

Env

CMoore said:
Not trying to put one of our sponsors on the spot, but.........
1. For making a Stop Bath..... Is there any "practical" difference between what is available on Amazon (food grade/non-gmo) and what is sold by Photographers Formulary.?

2. This warning form the PF website.....
6.2
Environmental precautions
Do not let product enter drains
.......I assume are they talking about Not Dumping the pure powder. There should be no problem with dumping a Citric Acid stop bath.?

Thank You

Citrinic acid is a danger to human health.
It has also the potential to be a danger to water organism. So there are a couple of facts to avoid environmental destructions.
One simple example to explain :
If you let 250000 gallons citinic acid
( 10% ) in a smal lake this will kill lot of water organisms and has also an possibble impact to ducks and water birds.
It is also poisoness : If you drink 2 gallons citrinic acid 25% at one time
you can get hard complications.
It has the potential to be lethal - with only a little more dosis (35 - 45% citrinic acid per gallon)

......

Ok - seriously : A stop bath on the base of citrinic acid is just a confortable (a luxury) form of a bw developer stop caused from its better smell.
The cheaper the better it is.And please don't buy it at Photographers Formulary.
Best you can get is 25% acid from supermarked.
But beware of : If you want to use it for food - it is concentrated (25%) don't drink it undeluted. Therfore on every bottle a warnig is on it.
Housewifes should know it also.

with regards

MattKing · Oct 9, 2017

I'm not sure what citrinic acid is, but I expect it is different than citric acid (although language differences may mean I'm wrong).
Powdered citric acid is pretty strong if you have it on its own. If you were to dump it down a drain, when it got wet in the drain the resulting solution would probably be a very strong and concentrated acid, held in a confined place, with a few other things around it that might very well react to a strong acid. Might not be a good idea.
If you drop a teaspoon of it in a litre of water - not so concentrated, so not nearly as much of a potential problem.
I've got a couple of bags of citric acid I got from a U-brew beer making place. I'm not overly worried about them.

Gerald C Koch · Oct 9, 2017

Citric acid is a moderately strong acid much stronger than acetic acid. In the lab where I worked we always flushed the drain after putting any chemical down it.

Svenedin · Oct 9, 2017

I used to use an indicator stop bath based on citric acid. This was sold as a liquid concentrate. I stopped (no pun intended) using it because bugs grew in the concentrate. Clearly it is biodegradable! Actually there is a biochemical pathway called the “citric acid cycle” (Krebs Cycle). All aerobic organisms use this pathway to release energy from food. It is not going to cause harm down the drain unless dumped in massive quantities. Would you worry about pouring orange juice down the drain?

Photo Engineer · Oct 9, 2017

Citric acid is a moderately strong organic acid as noted above, but no one has mentioned its BOD or COD which are the Biological and Chemical Oxygen Demand. This acid has a large footprint in consuming Oxygen in water during decomposition and thus it can retard the growth of fish or bacteria in water besides changing pH. So, it is not desirable to put the solid down the drain, but is reasonable to do it as a solution - in moderation!

PE

Barry Kirsten · Oct 9, 2017

I use the Kodak SB-8 stop bath formula: citric acid 15g per litre of water. I think at this concentration it'd be environmentally safe, given that it is diluted greatly in the drainage system. Certainly compared with other chemicals we use in photography, I think citric acid is relatively harmless. The only adverse comment I have seen about citric acid as a stop bath is that being organic it can develop growths in the bottle over time. I have a batch mixed about 8 months ago and it's still perfectly clear.

Svenedin · Oct 9, 2017

Barry Kirsten said:
I use the Kodak SB-8 stop bath formula: citric acid 15g per litre of water. I think at this concentration it'd be environmentally safe, given that it is diluted greatly in the drainage system. Certainly compared with other chemicals we use in photography, I think citric acid is relatively harmless. The only adverse comment I have seen about citric acid as a stop bath is that being organic it can develop growths in the bottle over time. I have a batch mixed about 8 months ago and it's still perfectly clear.

Mine grew white goo within a few weeks but maybe I was unlucky. I've not had the issue with acetic acid but organic growths can occur in vinegar so it can happen.

trendland · Oct 10, 2017

MattKing said:
I'm not sure what citrinic acid is, but I expect it is different than citric acid (although language differences may mean I'm wrong).
Powdered citric acid is pretty strong if you have it on its own. If you were to dump it down a drain, when it got wet in the drain the resulting solution would probably be a very strong and concentrated acid, held in a confined place, with a few other things around it that might very well react to a strong acid. Might not be a good idea.
If you drop a teaspoon of it in a litre of water - not so concentrated, so not nearly as much of a potential problem.
I've got a couple of bags of citric acid I got from a U-brew beer making place. I'm not overly worried about them.

Oh yes you are right is it the special compound of E6 "citinic acid" I often have mixed this in the past.
It is to avoid fog I don't remember right
but it may be part of the first developer.
But I am quite sure C.Moore does mean
CITRIC ACID....

with regards

trendland · Oct 10, 2017

MattKing said:
I'm not sure what citrinic acid is, but I expect it is different than citric acid (although language differences may mean I'm wrong).
Powdered citric acid is pretty strong if you have it on its own. If you were to dump it down a drain, when it got wet in the drain the resulting solution would probably be a very strong and concentrated acid, held in a confined place, with a few other things around it that might very well react to a strong acid. Might not be a good idea.
If you drop a teaspoon of it in a litre of water - not so concentrated, so not nearly as much of a potential problem.
I've got a couple of bags of citric acid I got from a U-brew beer making place. I'm not overly worried about them.

Totaly confused - No the compound I mixed sometimes (only from translation)
is just again CA. CITRACINIC ACID !

Sounds sometimes very simular these
acids ...........
Sorry best is to use cas.numbers to avoid mixing that is best method.
Yes - but here we have citric acid in diferent spellings ...
We all know the function in different cases (change ph).
Acetic acid will do the job in bw stopbath
also.

with regards

trendland · Oct 10, 2017

Gerald C Koch said:
Citric acid is a moderately strong acid much stronger than acetic acid. In the lab where I worked we always flushed the drain after putting any chemical down it.

I am not sure about : If you have concentrated (10%) acetic acid in comparison with concentrated (25%) citric acid - the last one is much stronger
as you stated !
But if both are in same concentration
( 10% ) there is a mighty difference ?
Is it realy much stronger ?
You might be right - but why is this so ?

with regards

trendland · Oct 10, 2017

Barry Kirsten said:
I use the Kodak SB-8 stop bath formula: citric acid 15g per litre of water. I think at this concentration it'd be environmentally safe, given that it is diluted greatly in the drainage system. Certainly compared with other chemicals we use in photography, I think citric acid is relatively harmless. The only adverse comment I have seen about citric acid as a stop bath is that being organic it can develop growths in the bottle over time. I have a batch mixed about 8 months ago and it's still perfectly clear.

Yes don't worry you are absolute safe
(environmentally) It is more a case to your leading lines theoratically.But you do not so 50times a day!
And it should be a case if you take it into
your aquarium but who is so stupid?
It is allways a question of concentration.
1/2 gallon 5% citric acid is deluted after some seconds with factor10 and when it reached first rats in the severage they obviously could smell it but delution is then under 0,001% because of more than some cubic meters of water.

with regards

Gerald C Koch · Oct 10, 2017

I can't find any references to 'citrinic acid.' It's most likely a misprint. Some years ago there was a chemical called citrazinic acid used in color processes. But it is IIRC not used in the E6 process.

Anon Ymous · Oct 10, 2017

Gerald C Koch said:
I can't find any references to 'citrinic acid.' It's most likely a misprint. Some years ago there was a chemical called citrainic acid used in color processes. But it is IIRC not used in the E6 process.

There's citrazinic acid, something used in E6 CD.

CMoore · Oct 10, 2017

What about the chemical itself...does it "matter" where i buy it from.?
Are these THree equally as able to make a decent Stop Bath.?
Thank You

1. http://stores.photoformulary.com/citric-acid/

2. https://www.amazon.com/Spicy-World-...F8&qid=1507654319&sr=8-9&keywords=Citric+Acid

3. https://www.chemistrystore.com/product.cgi?group=339&product=17474

darkroommike · Oct 10, 2017

If you are also putting your used developer down the drain mix the developer and stop bath together before you put it down the drain and flush with lots of water, just the water from your tray wash up, etc,., is probably sufficient. And if it fizzes (it might, might not) wait until it stops fizzing before it goes down the drain. And if you are using an indicator stop it's also fun to watch it turn from yellow to purple.

Wayne · Oct 10, 2017

Photo Engineer said:
Citric acid is a moderately strong organic acid as noted above, but no one has mentioned its BOD or COD which are the Biological and Chemical Oxygen Demand. This acid has a large footprint in consuming Oxygen in water during decomposition and thus it can retard the growth of fish or bacteria in water besides changing pH. So, it is not desirable to put the solid down the drain, but is reasonable to do it as a solution - in moderation!

PE

Stop making sense. This is the internet.

Photo Engineer · Oct 10, 2017

Yes Wayne, the internet. I'm trying to avoid "fake information".

Citrazinic acid is used in the E6 CD as a competing coupler to control Dmax and color reproduction. It forms a soluble green dye.

PE

Bob Carnie · Oct 10, 2017

adelorenzo said:
No difference AFAIK. I bought 25 lbs of the food grade stuff for about $75 shipped a few years ago. I don't bother measuring it too accurately, I have a little plastic scoop in the jar that I know roughly how much I holds.

Given that citric acid is a food ingredient I cant imagine how it would harm anything. I certainly pour it down the drain.

Where did you find that amount of citric acid ??

adelorenzo · Oct 10, 2017

Bob Carnie said:
Where did you find that amount of citric acid ??

I bought it on eBay. I also got 25 lbs. of sodium thiosulfate for about the same price. Here is the seller I bought it from, looks like it is a fair bit cheaper than it was when I bought it a few years ago and still free shipping.

http://www.ebay.com/itm/Citric-Acid...k-Consists-of-5-5-Lb-Packs-9751-/202056691022

Patrick Robert James · Oct 10, 2017

I get Citric Acid at the health food store. Not the cheapest way to buy it, $9/lb, but it sure is convenient! I keep it in a quart ice cream container and just leave a spoon in it. One heaping spoonful just happens to be the right amount for a stop bath. It is all very convenient. Plus, it doesn't smell like Acetic Acid. There is no indicator of course, but I don't put enough prints through it for it to matter. If I am in the darkroom more than a few hours, I just throw another spoonful in.

Arklatexian · Oct 10, 2017

Bob Carnie said:
Where did you find that amount of citric acid ??

Have you heard or read that drinking large amounts of orange juice over a prolonged length of time can affect the enamel of your teeth? I have and I don't think that the water in the OJ is the reason. As usual, when drinking anything, moderation is the key.......Regards!

Gerald C Koch · Oct 10, 2017

Anon Ymous said:
There's citrazinic acid, something used in E6 CD.

My bad! The 'Z' key on my keboard among others does not always make contact. Further citrazinic acid is used in the E6 color developer. I had the formulas here but decided to wing it without checking. Anyhow citrazinic acid competes with the color developing agent to lower the contrast of the top emulsion layer.

lensmagic · Oct 15, 2017

Photo Engineer said:
Yes Wayne, the internet. I'm trying to avoid "fake information".

Citrazinic acid is used in the E6 CD as a competing coupler to control Dmax and color reproduction. It forms a soluble green dye.

PE

Fake information would have us using digital cameras!

a few citiric acid questions

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