Pyro & Toxicity : LUSENET : B&W Photo - Film & Processing : One Thread

I've read some comments here and in Gordon Hutchings book about pyro being toxic. As I'm using it regularly, I'm interested if anyone can tell me about its toxicity. Is it cumulative? I believe it affects the kidneys. It's difficult to estimate how much a careful user might absorb if he/she is a frequent user, but how much do you need to cause an effect? Is the effect permanent? Is it carcinogenic? Any help would be appreciated.

-- john stockdale (, April 30, 2001


Look below and you'll find two other threads that address this topic. The instances Hutchings sites involve the tray processing of pyro negatives with bare hands in a photo studio darkroom every day for years. The amount even a sloppy user might get on his hands using a tank would be so little by comparison as to be negligible. Don't worry (and don't bathe in it). You'll be fine.

-- Brian Hinther (, April 30, 2001.

I wouldn't worry about the toxicity terribly. Wear rubber gloves at all times when handling the chemistry, and you should be fine. I've read that pyrogallol crystals are very dangerous for the lungs if the dust is breathed, so I recommend purchasing premixed chemistry (e.g. from Photographer's Formulary) rather than making your own from powder or mixing prepackaged powdered PMK.

-- Jim MacKenzie (, May 01, 2001.

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