Clarification about Pyro

[John Boeckeler]

Almost makes me want to go digital.

[Kirk Keyes]

Brian - if you look in the earlier thread, you will find mention of studies that have been done on rabbits and mice (see http://ntp-server.niehs.nih.gov/htdocs/Chem_Background/ExecSumm/Pyrogallol.html This document is written by the National Institute of Environmental Health Sciences - I again suggest that everyone take a look at this document and read through it at least once.)

A quarter of the way through the document you will find this sentence, "Lifetime dermal exposure of mice and rabbits to low doses of pyrogallol did not induce toxic effects." So while it apears that no one has done any tests to determine the chronic effects on humans, these tests have been done on mice and rabbits.

Pyro use in developers is exactly this kind of exposure - low dermal dosages. And as Jorge points out above, our photographic exposures are for rather short periods of time. If one adds in the protection that will be gained by the use of gloves, then the risk of exposure to the pyro in the first place is greatly reduced. Certainly much lower than the exposure you get by placing you hands into a tray of Dektol.

Speaking of Dektol, has any one here bothered to read the MDSD that Kodak has for it? See http://www.kodak.com/US/en/corp/environment/kes/healthSafety/pdfs/consumer/B_W.pdf. Kodak is talking about it when diluted as recommended, and it contains the sentence, "In case of contact, immediately flush eyes and skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes." This doesn't sound like something we would want to get anywhere near! But how many of us feel that Dektol is nothing to worry about?

Jeremy - one reason that I find nitrile gloves better is that they appear to be tougher than latex, and there is less risk of the tearing during use. Maybe I just have large hands, but I find that even with fresh latex gloves, quite a few seem to break immedately while putting them on. I rerely ever have a nitrile glove break like this. So I kind of feel that nitrile are better. And they are usually a cool blue or purple color, not that boring beige color that latex comes in! and don't be cheap - do not reuse your gloves. Replace them when you remove them.

Steve Simmons- how about the idea to find a toxicologist or a doctor that is knowledgable in industrial medicine? That would go a long way and most certainly be a very definitive article for the photographic field. Just make certain that references and sources are given, as you see the kind of response that appearantly unsubstantiated claims are given (and rightly so).

[Nick_3536]

"recommend exposure to no more than 2 mg/m3 of hydroquinone"

Could I get this in english? 2 mg per cubic metre? A cubic metre of what? Me? Air? Developer?

[Chris Gittins]

>Could I get this in english?

NIOSH and OSHA recommend that people not be exposed to more than 2 mg hydroquinone per cubic meter of air at any time.

That concentration refers to hydroquinone particulates in air, such as you might encounter when you're making up a stock solution. Take home message: wear protection to prevent inhallation of particulates, such as a dust mask, and work in a well-ventilated area when you're mixing up your D76, etc. stock.

The NIOSH guide I have does not offer any quantitative exposure guidelines with respect to hydroquinone dissolved in water, which will be the primary type of exposure once the developer is mixed. NIOSH's only recommendation with respect to dermal exposure is to prevent it.

[mark blackman]

Steve, I for one am grateful that you've bothered to cover this subject, and look forward to reading Richard's comments, which I'll take on board and deal with as an adult.

I sometimes wonder about the negative crap posting on here, is it jealousy I wonder, and why does it all seem to emanate from the USA? View Camera may not be the best photography magazine in the world but it certainly is the only one I know of that covers the LF scene.

All you need to do to make me a really happy bunny is conifer the same rights you give to your American subscribers to those of us elsewhere.

[Brian Ellis]

Kirk - I apparently didn't make my point clear. As I said, I have no idea whether pyro is toxic or not (and don't care, I don't use it though I have in the past). I also have no idea (and don't care) whether any studies have been done on humans, mice, rabbits, space aliens, or anyone or anything else. I just find it extremely odd that someone would say in one sentence that no studies have been done concerning its hazardous nature and in the next sentence say it isn't hazardous. I just don't see how one makes the leap from the first sentence to the second. That was all I was pointing out. As to whether it is really hazardous or not, and as to what studies, if any, have been done, I'll leave the arguments about that to the people who use it and care but I'm not one of those people.