Borax purity grade

john_s · Dec 9, 2007

It depends what the impurities are too. Once I was agonising over whether to buy 96% or 98.5% sodium sulphite. I asked the suppliers what the impurities were, and it was mostly sodium sulphate, which is not going to do anything noticeable in a developer or a fixer or a wash aid. The problem then was simple, since the price differential was significant.

What sort of impurities would be bad news for a developer? Insoluble stuff will settle, if you have time. Metal ions? What else?

Photo Engineer · Dec 9, 2007

Halides, Calcium, Magnesium, Sulfides. Lots of things actually.

Photograde chemicals are certified to have the right proportion or lack of these items. You don't want sodium bromide with sodium iodide in it for example, or you don't want carbonate with halide in it.

The list is long.

PE

gainer · Dec 9, 2007

I certainly would not use iodized table salt to make up the 50 grams or so of an ersatz Microdol X, but it would take much more than 1 0r 2% of NaCl in the 2 grams of borax in a liter of D-76 to have any measurable effect on that batch. In any case, you don't want salt in soap, as you know if you've been in the Navy or even on a troop ship. (far fetched, of course.) What surprised me most in this interchange about the evils of cheap borax was the 0.89% of impurities allowed in a batch of analytical grade sodium tetraborate decahydrate. What also surprised me was the fact that certain of our resident chemists would make a blanket statement about the unsuitability of household borax without identifying the actual impurities that make it unsuitable. The pentahydrate or the anhydrate could, in some uses, qualify as an impurity when the borax is used as a quantitative analytical reagent, but would have no effect that we could measure or even see. I know, better safe than sorry, but if 99.11% purity qualifies as analytical grade, you could be safe AND sorry without knowing why. Now, if the allowed impurities were known to be photographically inert, like quartz particles, we could tolerate, probably, 95% purity as long as the impurities settled out or dissolved. As you know, I have been using nearly saturated solutions of borax in some developers and have not seen any sign of sediment or colloidal suspension when I use 20 Mule Team Borax. If there are any harmful soluble impurities, they have not shown up in any photographic way.

Photo Engineer · Dec 10, 2007

Patrick;

Sometimes it is not what the impurity is, or how much is present, but rather the amount of variability that is introduced by the variability in manufacturing a 'cheap' household product compared to a photo grade chemical.

As an example, Detol contains bromide. Today, most papers are high in chloride and some are pure chloride (or nearly so). Any variability in bromide purity or any iodide salt in any of the chemicals causes a big swing in speed and contrast of chloride papers. Iodide in some salts in developers for films changes the edge effects because iodide is a 'buffer' for edge effects.

So, some hidden or difficult to measure effects may vary and qualitative or eyeball tests will not show it. And, BTW, this becomes even more critical in color.

PE

gainer · Dec 10, 2007

Photo Engineer said:
Patrick;

Sometimes it is not what the impurity is, or how much is present, but rather the amount of variability that is introduced by the variability in manufacturing a 'cheap' household product compared to a photo grade chemical.

As an example, Detol contains bromide. Today, most papers are high in chloride and some are pure chloride (or nearly so). Any variability in bromide purity or any iodide salt in any of the chemicals causes a big swing in speed and contrast of chloride papers. Iodide in some salts in developers for films changes the edge effects because iodide is a 'buffer' for edge effects.

So, some hidden or difficult to measure effects may vary and qualitative or eyeball tests will not show it. And, BTW, this becomes even more critical in color.

PE

There is no disagreement there, as far as I am concerned. The disagreement on my part is that some household products may actually be required to be more pure than would be required for photographic use. The analytical reagent use of borax appears to require no more than 99.11% purity. Is that sufficient for medical use? Would we not want to know the nature of the impurities? But because we do not seem to know what the purity of 20 Mule Team Borax is, or what its impurities might be, we resort to something that is certified by some vendor as "Photographic quality" which, for all we know, may have come out of a barrel of 20 Mule Team Borax, and even if we knew it to be analytical reagent grade, we still don't know if it could have come out of the same barrel, simply because we do not know the purity of 20 Mule Team Borax that we get at the supermarket. Talk about assumptions!

Is there some test we photographers could do in order to find out if indeed there is sufficient reason to avoid using the "cheap" stuff? BTW, I don't think cheapness has much to do with my choice. It is more a case of ready availability. If I run out of borax, I cannot run out and get the analytical grade, or the so-called photographic grade, but I can get what I have used for at least 60 of my 80 years within 10 miles of my rural home.

Photo Engineer · Dec 10, 2007

And I can't disagree with you either.

I can only say that the variability may be on the micro scale of image quality in negatives and may not be visible unless you do direct comparisons or quantitative tests, and so you may not get the best out of your imaging process.

I know you are right when you say that certain impurities vary for human consumption that cannot be present in photo chemicals and vice versa. I've seen that before. Silver salve uesd for human skin in burn cases is not of the same purity as silver metal used for making emulsions and so on and on and on. I cannot give exact figures on effects nor can I list the possible impurities that cause these problems, nor can I give amounts that can be tolerated. I have run quantitative tests in the past to show that there are tolerable limits and intolerable amounts of many 'impurities' in photo systems. Thats about it.

PE

DarkroomExperimente · Dec 10, 2007

"As an example, Detol contains bromide."

what is Detol?

never heard of that before...when I googled it I came up with a type of soap, but didn't see anything that seemed related to photography

Photo Engineer · Dec 10, 2007

DarkroomExperimente said:
"As an example, Detol contains bromide."

what is Detol?

never heard of that before...when I googled it I came up with a type of soap, but didn't see anything that seemed related to photography

Sorry, DEKTOL.

Typo.

PE

DarkroomExperimente · Dec 10, 2007

thanks, my typo-detector wasn't working

gainer · Dec 10, 2007

I think PE meant "Dektol", which usually contains KBr in its recipe and definitely in the packaged product.

The 20 Mule Team box says unequivocally "Contains no phosphates or chlorine." If it contains any sand, I have never seen it, and I think I would have if it were there. It has been used as a flux for brazing and silver soldering, and the borax bead that is well known in flame testing.

I still don't know how we are assured that the borax we buy from a photochemical supplier is any more pure than what we get in that box, or conversely, how we know that the box contains a less pure product for photo purposes. The MSDS, as we have seen in the past, only warns of hazardous materials, and may report such oddities as "Borax....100% +/-1%." Is there a test by which the supplier can be assured? Or is the world taking the other guy's word for it, who is just having a big laugh while he gets a jug of household borax, photo borax, assayer's borax, medicinal borax... all from the same barrel?

dancqu · Dec 10, 2007

gainer said:
...the so-called photographic grade, ...

So-Called! Photo Grade is every bit as much
a Grade as is USP. Even today, I dare say, World
Wide each month tons of PHOTO GRADE chemicals
are being shipped. Dan

Kirk Keyes · Dec 10, 2007

Patrick - While I don't have details on Photographic Grade chemicals, I do have info on ACS (American Chemical Society) Reagent Grade chemicals (which will say "ACS Grade" or "Reagent Grade" on the label. According to the 4th Ed of "Reagent Chemicals, American Chemical Society Specifications", sodium borate (aka Borax or sodium tetraborate) must pass specifications for the following requirements:

Insoluble Matter: not more than 0.005%
pH of a 0.01M solution: From 9.15 to 9.20 at 25C
Chloride: not more than 0.001%
Phosphate: not more than 0.001%
Sulfate: not more than 0.005%
Calcium: not more than 0.005%
Heavy metals (as Pb): not more than 0.001%
Iron: not more than 0.0005%

Differences from Photographic Grade, I don't know. I don't have the specs. But I suspect it is similar.

PE mentioned the following: Halides, Calcium, Magnesium, Sulfides. Halides may fall under the test listed for Cl, but Mg and Sulfide are not listed for ACS grade. The tests are generally easy to do, and only a few specify atomic absorption equipment, but being the gadgeter that you are, I'm sure if you got a copy of Scott's "Methods of Chemical Analysis" from the 1920, you could hack out a few of these tests at home. I think Google books has that online for one of the early editions.

Kirk Keyes · Dec 10, 2007

Oh, and I understand that AR (analysed reagent) grade is ACS (or Reagent) grade that has had the batch analysed and the results of the analysis are printed on the label so that you can verify that your needs will be met by the results of that batch analysis.

Perhaps Mick could give us a list of the specifications on his bottle?

Photo Engineer · Dec 10, 2007

Kirk;

Usually the ACS analytical grade lists those contaminants most commonly found in a given type of reagent. Thus there is usually no analysis for something that is not usually found. A pro forma test is made but that is about it. So, you don't expect to see Tellurides or Selenides or Sulfides in Borax and so a simple test to show presence or absence is sufficient.

The ACS grade above is close to exactly photo grade. In fact we used ACS Analytical grade for almost everything.

PE

gainer · Dec 10, 2007

Kirk, having that information is part of the solution. The other part is finding the analysis of 20 Mule Team Borax, since the argument at hand is whether the borax at the supermarket is good enough for most photographic purposes, which I take to mean any use where borax is specified as part of a solution for processing black and white film, but a particular grade is not specified.

In my three years of study of chemical engineering at WVU I did well in qualitative and quantitative lab courses. What got me to change to aeronautical engineering was physical and organic lecture and lab courses, a lecturer who didn't know how to lecture, a 21 credit-hour load, courting my future wife, and I forget what else, all in the same semester. I made the mistake of studying all night before finals. I drank tea that was so dark you couldn't see through it, brewed in a coffee percolator. The tea wore off suddenly about the time the exam began and I don't remember anything until the assistant woke me when time was up.

Photo Engineer · Dec 10, 2007

Kirk;

I forgot.

Insoluable matter than cannot be filtered out well can absolutely ruin negatives by leaving small particles trapped in the emulsion.

PE

Kirk Keyes · Dec 10, 2007

Here's a link to Scott's Vol. II
http://books.google.com/books?id=CpUAAAAAMAAJ&pg=PA1289&dq=scott+chemistry+analytical#PPR1,M1
if anyone is interested in seeing what it's like.

Kirk Keyes · Dec 10, 2007

Well Pat, here's how you do the insoluble matter test, from the ACS book:

Dissolve 20 g in 300 ml of water, heat to boiling, and digest in a covered beaker on the steam bath for 1 hour. Filter through a tared, porous porcelain or a platinum filtering crucible, wash thoroughly, and dry at 105C. The weight of the residue should not exceed 0.0010 gram.

You've got the 20 mule team, hitch'em up and drive them to the lab.

Murray@uptowngallery · Dec 10, 2007

Doesn't have anything to do with borax, but just generally speaking toward subtleties, I find it interesting how some kallitype/VanDyke Brown/Argyrotype color/tone results in the final print depend upon the humidity in the sensitized paper.

There are so many variables and variations, who really knows.

I did find an alternate source of borax for those who are happy with bulk alternative suppliers- I can't remember the exact name but it's a swimming pool product called ProTeam something, maybe ProTeam Supreme made by Haviland in Grand Rapids, MI. I intend to call them some morning when I remember & ask about purity. What will probably happen is, as PE Ron says, they'll tell me 95% and I'll have some thing to worry about.

Murray@uptowngallery · Dec 10, 2007

Murray@uptowngallery said:
Doesn't have anything to do with borax, but just generally speaking toward subtleties, I find it interesting how some kallitype/VanDyke Brown/Argyrotype color/tone results in the final print depend upon the humidity in the sensitized paper.

There are so many variables and variations, who really knows.

I did find an alternate source of borax for those who are happy with bulk alternative suppliers- I can't remember the exact name but it's a swimming pool product called ProTeam something, maybe ProTeam Supreme made by Haviland in Grand Rapids, MI. I intend to call them some morning when I remember & ask about purity. What will probably happen is, as PE Ron says, they'll tell me 95% and I'll have some thing to worry about.

They have a "PLUS" version, that has boric acid and fragrance. That's not the one.

gainer · Dec 11, 2007

Kirk Keyes said:
Well Pat, here's how you do the insoluble matter test, from the ACS book:

Dissolve 20 g in 300 ml of water, heat to boiling, and digest in a covered beaker on the steam bath for 1 hour. Filter through a tared, porous porcelain or a platinum filtering crucible, wash thoroughly, and dry at 105C. The weight of the residue should not exceed 0.0010 gram.

You've got the 20 mule team, hitch'em up and drive them to the lab.

Well, now, is that the requirement for film developing or for some other purpose. Did you run that test to see if the borax you would use for D-76 meets the spec? Do you have someone's word that the insoluble matter in 20 grams of your borax does not exceed 0.0010 g? You're putting me on, aren't you?

gainer · Dec 11, 2007

Photo Engineer said:
Kirk;

I forgot.

Insoluable matter than cannot be filtered out well can absolutely ruin negatives by leaving small particles trapped in the emulsion.

PE

I have made many lousy negatives in my time, but I can't say I ever observed that one. Over and underexposure or over or under development I have seen often, and motion blur and focus errors too, but most of my bad negatives were just not good pictures to begin with. In the old days of softer thicker emulsions I had my share of reticulation as well. I have to admit that I did not always use borax in my developers. In my days of photographing from my chair as first oboist of the Norfolk and Peninsula Symphonies, now merged into the Virginia Symphony, My favorite developer was a phenidone, hydroquinone, sulfite concoction with no other alkali.

Kirk Keyes · Dec 11, 2007

gainer said:
Well, now, is that the requirement for film developing or for some other purpose.

That's the requirement to meet the specifications for ACS Reagent Grade, just as I plainly stated above.

Mick Fagan · Dec 11, 2007

Well I'm not sure if this will work, I typed it into word and am just going to paste it.

It's what is written on my bottle of reagent grade Borax.

Analytical Reagent grade Sodium Tetraborate

Na2B4O7, 10H2O = 381.43

Assay = 99.101%

Insoluble 0.005%
Cl 0.001%
PO4 0.001%
SO4 0.005%
Ca 0.005%
Fe 0.0005%
Heavy Metals (as Pb) 0.001%

Hmm, the subscript numbers have all come out at the same size as the rest of the type. What I did was to underline all of the numbers which should have been subscript characters.

Mick.

gainer · Dec 11, 2007

I finally learned how to use the Acrobat reader to search the net. 20 Mule Team Borax is the Technical grade and contains greater than 99% sodium tetraborate decahydrate. It contains no chlorine and no phosphates. 20 grams will not dissolve in 300 ml water at 20 C where the solubility is 4.71% by weight. All the good tables and curves are shown. Have a ball. I will continue to use the cheap stuff for anything I'm likely to do in the darkroom.

Borax purity grade

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