Benzotriazole questions ...

[karthik]

I am looking into using Benzotriazole (BTAZ) to revive some fogged Kodak Polycontrast Rapid II RC paper, and have a few questions.

1. Sourcing: Is there any place in Vancouver that sells BTAZ, either in pure form or in solution (like Edwal Liquid Orthazite)? Leo's doesn't have it. Is Photographer's Formulary my only choice?
2. Disposal: What exactly is the recommended procedure? The MSDS I have been able to find online for BTAZ or Liquid Orthazite type products specifically say that it should not be allowed to enter the sewage system. I have also found papers online which show the persistence of BTAZ as a water pollutant since it is not broken down easily.
3. What happens to BTAZ eventually (i.e., by the end of the printing session) when I add a bit of it to my paper developer?

Thaks --- Karthik

 

[Ian Grant]

I don't know about sourcing but disposal well . . . . .

The level used in developers is extremely low, if you're worried about pollution then there's far worse in every domestic household and you've not thought or worried about that.

You can send your waste developer for disposal, but all that happens is they have a licence to pour it down the drain. I worked for a licensed waste disposal company and specifically with the regulators with regards to photo chemicals, all the water boards (UK) wanted was silver recovered, solutions effectively neutralised and released slowly, but we were talking many 1000's of litres at a day. They were concerned with the load (dilution) at sewage treatment works. I was dealing with London which had very strict levels, like New York, Toronto etc.

Ian

 

[nworth]

The last time I looked, Photographers' Formulary still supplied benzotriazole. It is usually used in a one or two percent solution and very small quantities. Disposal rules vary from one political jurisdiction to another. Benzotriazole is pretty harmless, however, and disposal of small quantities like these down the drain is generally permitted.

 

[2F/2F]

There is also Bostick and Sullivan.

 

[Iwagoshi]

Try Calumet, or do an (there was a url link here which no longer exists), I believe someone posted an alternative home brew and chemical information.

 

[Mahler_one]

Artcraft has it...just checked.

artcraftchemicals.com

 

[tac]

I got it from Artcraft. Also, buy the smallest quantity you can; a little bit goes a long way. It doesn't dissolve well in water, so I use 90% isopropyl alcohol to make up a 10% solution, then measure that solution accurately with a 1cc syringe. Let us know what you discover!

 

[karthik]

Thanks everyone for the suggestions. I'll get it from Photoformulary/Artcraft.

 

[MartinP]

That name brings back memories - 'Kodak Polycontrast Rapid II RC paper'. When I worked in a lab that was used for the cheapest grade of black-and-white machine printing that we made. For our own non-serious work, and through the same machines, I used Ilford Multigrade RC. Sorry if this sounds a bit argumentative, it is not meant in that way, really just to say there are better products easily available, but IMHO that paper is really not worth struggling with - unless maybe you have a special process for something which will only work with Polycontrast I guess.

 

[MattKing]

Glazer's in Seattle had some Photographer's Formulary benzotriazole on the shelf when I was last there.

 

[karthik]

That name brings back memories - 'Kodak Polycontrast Rapid II RC paper'. When I worked in a lab that was used for the cheapest grade of black-and-white machine printing that we made.

That's interesting. I got 250 sheets for free and was curious about its vintage - Google shows up so little related to this paper that I thought the label had a typo. I presume it predates the internet and nobody cared for it enough to ever write anything about it online.

I don't really have any particular reason for playing around with this other than the fact that I prefer experimenting with this instead of papers I normally use.

 

[Wade D]

I have always used potassium bromide (KBr) as a restrainer to limit age fog on film/paper and it works well. It lowers the speed of the film/paper a bit. Older film/paper requires a longer exposure anyhow to get usable tones above the base density.

 

[Ian Grant]

I have always used potassium bromide (KBr) as a restrainer to limit age fog on film/paper and it works well. It lowers the speed of the film/paper a bit. Older film/paper requires a longer exposure anyhow to get usable tones above the base density.

The downside with some papers is that adding KBr rapidly increases the warmth, not an such an issue with Bromide papers or films but it can lead to muddy tones.

A little Benzotriazole has a substantially larger effect.

Ian

 

[bdial]

As a starting point, how much benzotriazole do you use for reducing fog, or cooling the tone?

 

[Ian Grant]

10 - 20ml of a 1% Benzotriazole solution, add in 10ml steps until you get no more cooling effects, too much will just reduce paper development.

Ilford IBT is a 10gm Benzotriazole in 1 litre of 1% (10g/litre) Sodium carbonate (anhyd). That's 10g of each but dissolve the carbonate first.

Ian

 

[bdial]

Thanks Ian.

A 1% solution...
I guess the 100g jar I just got from Artcraft will be a lifetime suppply. Though I do have several boxes of age-fogged free paper.

 

[Gerald C Koch]

Don't use the Ilford product in film developers as the carbonate will throw the pH of the developer off. In paper developers bromide will warm the tone while benzotraizole will cool it down. Using too much will produce a definite blue tone with some papers.

Try www.techcheminc.com, $15 for 100 grams of benzotriazole. Gppd source of many photo chemicals.

 

[Ian Grant]

Benzotriazole was often sold in a Sodium Carbonate solution, and this can only be beneficial when used in film processing because on it's own the Benzatriazole drops the film speed the very slight increase in pH will help offset this. But we are talking small, as a 30ml/litre addition of Ilford IBT has quite a strong restraining/anti-foggant effect, and the 0.3g Sodium Carbonate it contains is fairly insignificant.

Ian

 

[Mike Wilde]

>Sourcing: Is there any place in Vancouver that sells BTAZ, either in pure form or in solution

Send me a PM with your postal adress, and I will mail you a few weighed out grams. I bought a bottle of the stuff before Claire closed JD Photochem down, and it is several lifetimes worth for me.

 

[Gerald C Koch]

Benzotriazole was often sold in a Sodium Carbonate solution, ... 30ml/litre addition of Ilford IBT has quite a strong restraining/anti-foggant effect, and the 0.3g Sodium Carbonate it contains is fairly insignificant.

Ian

The amount of carbonate cited in the example (0.3 g) will seriously effect the action of poorly buffered developers such as D-23 or D-76.

 

[Ian Grant]

The amount of carbonate cited in the example (0.3 g) will seriously effect the action of poorly buffered developers such as D-23 or D-76.

0.03% Sodium Carbonate isn't going to have any significant effect on a developer already containing 10% Sodium Sulphite which on it's own has a pH of 9.9

Benzotriazole is not recommended for film developers anyway due to it's effect on film speed and Dmax.

Ian

 

[Gerald C Koch]

With fresh film added antifoggants are usually not needed with many commercial developers. However, they may be required with film that is old or improperly stored.

Benzotriazole or another anti-fog is positively required in the formulation of phenidone based developers as this family of developing agents produce quite a bit of developer fog. Look at the Kodak patent for HC-110.

There are also other uses, for many years Kodak recommended adding benzothiazole to fine grain developers such as Microdol to lengthen development time and therefore the emulsion's contact with the high sulfite solution.

For reasonable amounts of benzotriazole, if you look at the development curves for a particular developer with various concentrations of benzotriazole added you will find that the curves are identical merely shifted to the right toward longer development times with increasing antifog concentration.

 

[Ian Grant]

2 issues.

Benzotriazole shouldn't be used with a previously exposed "old" film of unknown provenance, however it may be beneficial if you want to use old film in your camera & test the film/developer combination with it added first.

PQ developers don't need Benzotriazole to prevent base fog at all - they are already better than an MQ dev in that respect, the only reason it's added to print developers is to give Colder tones because with none PQ developers are far warmer than MQ equivalents. Very early Ilford commercial PQ devs gave problems with Bromide papers, customers complained of image colour shifts.

Ian

 

[Gerald C Koch]

PQ developers don't need Benzotriazole
Ian

Phenidone and its derivatives do not cause fog with low speed film emulsions or when used in low pH developers. But as film speed and/or developer pH increases one is required. This may be due to the fact the phenidone is not as sensitive to bromide concentration as metol. For this reason they are already present in commercial developers. The user may not wish to add additional antifoggant but one is already there. That was my point, I was commenting on the assertion that antifoggants were never needed for film developers.

 

[peoplemerge]

Resucitating this old thread because it helped explain a head scratcher tonight. Using slightly old paper, I ran out of Ilford PQ Universal (1+9). I mixed up some fresh Dektol, and suddenly my paper is fogged! 1/2 oz (per quart working soln) Edwal liquid orthazite doesn’t even come close to the pearly whites I saw with PQ but I can get there dropping from 2m to 90s in the Dev bath. Thank you, Photrio community!