The Perils of Pyro???
On a rainy Saturday, it's my family's custom to hie ourselves to a Barnes and Noble about 20 miles from our home to drink coffee and read. (The seven year old happily curls up in the children's section...but has no coffee that we know of.) I like to catch up on all the photography magazines to which I don't subscribe and will usually buy the ones that offer something worth taking home.
Today, in the May/June issue of Phototechniques, I came across an exceedingly forthright essay by Howard Bond titled: "Pyro Investigation: Pyro's Benefits May Not Be Worth Its Costs" in which he compares the results of several negatives of the same subject developed in D76 and PMK Pyro and the consequent prints including one coupled with an unsharp mask. His conclusion seems to be that the "meager benefits" that might be detected by use of pyro are significantly compromised by it's inherent health hazards, and certainly don't hold a candle to the benefits of unsharp masking in terms of sharpness. He writes: "A biochemist friend told me that the pyro molecule is similar to the pesticide molecule that has been giving Canadian farmers Parkinson's disease (not proof, but a red flag). Anecdotes don't prove anything, but it is interesting that the most famous pyro user, Edward Weston, died of Parkinson's disease." He further states in a subsequent paragraph: "Granted, I am not aware of any proof that long-term low-level exposure to pyro causes a specific health problem. On the other hand, the only evidence a pyro enthusiast can offer for the safety of its use is "Nothing has happened to me yet."
So...though I've bought the "Book of Pyro" and the PMK kit that comes from Bostick and Sullivan, it shall remain unopened until I am sure beyond any reasonable doubt that it is safe...including the remote consequences of inadvertant exposure by accident.
Many on this site seem to be enamored of the stuff. I'd like to suggest a discussion that offers an alternative view or corroborates Howard Bond's assesment.
see, I am a Rodinal user. It is extremely easy to mix and cheap!
I just don't see the point of having to mix all the chemicals for the pyro formulas.
Also, Rodinal has been around quite a long time and doesn't seem to have ill effects on anybody.
so for me its Yay for rodinal...
This was already discussed a month or so ago. Maybe try a search of the archives - I'm too lazy to do it myself.(At least I think it was here. It might have been over at photo.net now that I think about it) One thing someone in that thread pointed out was that Bond was comparing the developers with TMax, and that the T-grained films, TMax in particular, tend to be the least suitable for pyro developers. It also discussed that all chemical formulas are toxic in the right circumstances, and that most modern pyro formulas are so dilute that while the wearing of rubber gloves is recommended, the same could be said for pretty much all photo chemicals.
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Being rather impulsive and impetuous, and always wanting to try new THINGS, I do appreciate your note, John, which presents a warning toward another view. So thanks, 'cause I too like to frequent the coffee shoppes with my 4 1/2 and 6 year old wee ones. And, I'd like to continue doing so.
K. L. Taylor
Black and White Studios
I believe there is very through discussion at the LF forum about this. The article is nothing more than another pitch for unsharp masking by Howard Bond. There are many things in the article that are if not inaccurate they are at least biased. For one, he used PMK with tmx 100, a film that most everybody that uses PMK knows it does not stain as well as most other developer.
As to the toxicity, Bond cites the book by Susan Shaw, a book that is full of errors and is nothing more than a compilation of MSDSs or toxicity data, without any regard to the use and method of use of the chemicals and certainly without any intelligent analysis.
To judge toxicity you need to look at 3 important factors. Chemical concentration, length of time exposed to the chemical and route of entry into the system.
Lets start with the concentration. I dont recall exactly the LD50 of pyro, but I remember is somewhere around 250 mg/kg. With PMK you start with a 10% stock solution, so if we fudge a little and set the density of this solution to 1, you have in the stock solution 100,000 mg/kg. To use it you then dissolve the stock solution a 100 fold, leaving you with approximately 1000 mg/kg. Now, lets say the average person who uses this developer is 176 pounds or 80 Kg. If you multiply 80 x 250 mg/kg, you find that a dose that would be harmful to you would be around 20,000 mg/kg. IOW 20 times more than what you use for developing and twice as much than what is contained in the stock solution.
Lets move on to the length of exposure time. The LD50 doses are arrived by feeding the subject big amounts of the chemical on a daily basis until 50% of the subjects die. This can take days, weeks or months, depending on the chemical. Unless you plan to add 20 grams of pyro to your diet on a daily basis, the chances that you will be exposed to pyro long enough to cause you harm are close to infinitesimal.
Now, finally we move on to the route of entry. Lets say you decide to develop with PMK and you put your hands in the developer without gloves. Lets further assume that you absorb all of the pyro through your skin (clearly impossible, the pyro would be gone and you would not have a developing action). At this time you have been exposed to a dose that is 20 times lower than the one determined to be harmful and if you stop developing, you have only been exposed for a small amount of time.
Of course, if you develop everyday, take no precautions and eat, drink and smoke in your darkroom, well then yes your chances of getting sick are greater, but it might not be only because of the pyro.
Now, the sentence about the pesticide. First, pyro is used in hair dye, I dont see people dropping off like flies after getting their hair tinted. Second, just because it is similar, does not mean it is the same, nor that it has the same effects on the body. Funny thing is, D76 has a developing compound that is very similar to pyro, yet we dont see Bond making any objections to it.
The Parkinson's statement is so ridiculous it chaps my hide. For one, Weston also used amidol, another benzene derivative, for another, there are millions of people who get Parkinson's without ever coming within 50 miles of pyro. His statement that people say "well nothing has happen to me" as proof of safety should not even be written, since he only offers the case of one person who happened to use pyro and get Parkinson's. How stupid is this?
Bottom line John, the article is a self serving ad for his unsharp mask and his workshops, he wrote about things about which he has no knowledge based on the flawed and alarmist research of a woman whose only merit was to read MSDS sheets and write about them on a terrible book.
It is unfortunate that people like him write these things and they become part of the "truths" of photography, just because Bond said it.
I cannot guarantee you 100% that nothing will happen to you, but with a little bit of care, good laboratory practices and a little bit of common sense I can guarantee you that if a drop falls on your arm, your gonads are not going to shrivel. All this based on careful analysis of the evidence, not on some hear say, or faulty information from from a woman that was too lazy to think.
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No, Noblebeast (that's fun to type) the article from Phototechniques is not the one to which you refer. Nor was it a topic here in the time I've been a habitue...(February). I suspect Mr. Bond..... Howard Bond (that's fun to type too) is on a bit of a crusade and may be so in several forums. I think if someone suggested leprechaun sweat was a magic elixer of photoformulary, someone else would be happy to debunk it. But in this case, aside from the, as he put it, "meager benefits" the safety concerns are the secondary but more critical issue.
When I first began to read this forum I was new to the term "pyro-cat" and laughed out loud at the notion that 'Garfield' had a cousin who shared my passion for analog photography. It's easy to be swept up in the tsunami of ULF and arcane materials as grails seeking questers (or are they questors). But, health issues are no joke. I still invite those who are practicioners to hold forth...or at least make a credible case.
I seem to have been typing when Jorge was....sorry about that.
IMO Howard Bond didn't research the subject very well and produced a very biased report.
The World Health Organization has some very good literature on this subject. The Benzene Ring compounds used for photographic developing are all toxic and pyrogallol, pyrocatechol and hydroquinone all occur in nature. However, these chemicals all oxidize and break down very quickly in nature - unless there is a massive contamination event (like the massive dumping of Pyrocatechol in China).
These Benzine Ring compounds all represent a health threat if their dust is inhaled, if they are ingested, or if they are absorbed through the skin. Reasonable safety precautions (like Nitrile gloves, masks, etc.) can reduce or eliminate these risks.
If you are a tobacco smoker, you have taken a fair amount of Pyrocatechol and other related Benzene Ring compounds into your respiratory system already (and this is not a good thing).
Hydroquinone has the same molecular formula and weight as Pyrocatechol, with the Hydroxyl attached to a different site on the Benzene Ring. Hydroquinone is a major component in both D-76, HC-110 and Dektol to name just a few developers. Hydroquinone requires the same safety/handling precautions as Pyrogallol and Pyrocatechol.
Arguably, the safest and least toxic developers are the Phenidone/Ascorbic Acid developers - like Pat Gainer's brews - but you really don't want to drink them, either.
Everything is analog - even digital :D
No problem John, I could go on and on about what all is wrong with the article, but I did not want to bore people and my answer was long enough as it is.
Originally Posted by jovo
Well if your that conserned about Pyro, what about DiHydrogen Monoxide? It been involve in more deaths than Pyro, and is use to compound every formula I know about. It's been found in every
cancer tumor study. It can burn you in it's gasious state and can
cause death if your lungs become saturated with it. Yet every
photochemical manufacturer still uses it!
"Just because nobody complains doesn't mean all parachutes are perfect."