John, wherever you got those posts from, they were not from me. I have found a post from you here
which I do not recognize as anything I have ever written. Could you possibly have got this material from my co-author Steve Anchell? Wherever you got it from, I don't think much of it.
Regarding Pyrogallol and toxicity, I really think Gordon Hutchings is the expert on this; I trust his asseveration that the chemical is unusually dangerous -- certainly more so than HQ. To take an MSDS as a literal statement of established scientific truth is ridiculous. They are often contradictory or have a commercial agenda. Gordon is not a scientist but he has done a good three decades of careful research on this chemical. I don't think the observations in his book are fanciful. Just my opinion.
Thanks, Ron, for looking out for my back! Greetings and best wishes to everyone !
Originally Posted by john_s
PS: Don't use mercury without exceptional protection!!! Arnold Newman told me it was the one chemical he wouldn't let his assistants use. He thought it too dangerous, he didn't want the responsibility of harming them. So on the rare occasions he's had to use it, he did it himself. What a guy!
I'll revise my list of toxicity to include Pyro, Selenium, Mercury and Cadmium not necessarily in that order. They are all nasty!
I agree with Bill, mercury is not to be trifled with. As part of a large team at Kodak, we worked hard to eliminate Mercury and Cadmium from films and papers. I was on the color paper team. We also virtually eliminated Mercury. A tiny amount of mercury remained in one layer of color paper.
Apologies to Bill Troop
Bill, I have done you an injustice and I apologise. The notes that I had were in a clipboard of various notes which I had collected that expand on the contents of "The Film Developing Cookbook" and which I had entitled "Anchell and Troop" and the article was in fact by Steve Anchell. I am really sorry that I was so careless. The web address of that article is:
So again, please accept my apologies, and I take the point made by PE that everyone knows how dangerous mercury is, and would act accordingly.
Thanks very much, John! You really had me worried for a minute there. I was thinking -- could I have lost my mind and actually written that stuff about mercury? Steve is the greatest co-author ever, but -- let's put it this way: I accept full responsibility for every syllable in the Film Developing Cookbook. I don't accept any responsibility for anything Steve has written on his own. With regard to the general issue of carcinogenicity, as we all know, there would be few women left on Earth if the photographic chemicals commonly used in hair dyes were all that carcinogenic. Somehow, in over a century of use, there seems to be little decisive linkage. With regard to pyro, the chemical, throughout most of the 20th century, was used so many orders of magnitude less than HQ that the medical evidence (and the need to acquire it) simply isn't there. I know Steve believes that careless pyro use was responsible for health problems with the Weston men; that hasn't been medically established; it's anecdotal opinion. But there is a lot of anecdotal opinion out there. A lot. Since we will never know just how dangerous pyro really is (because it will never be used enough to warrant the research), it seems to me prudent to treat it with extra care. What's the harm in spending a few more minutes in the darkroom making sure you minimize your exposure to chemicals? The darkroom is a serious place; it's not a playpen.
Originally Posted by john_s