Pyrogallol: Crystalline, Very Fine Powder or Both?

Snapshot · Aug 13, 2007

Hi All,

I have recently purchased some pyrogallol to make PMK and 510-Pyro film developer (my pyrocatechol hadn't arrived to make Pyrocat-MC). However, the pyrogallol seems to be a very fine powder when I was expecting a more crystalline structure. It does appear to be vaguely crystalline but it is so fine that it easily dissipates into a cloud. For some reason I felt there was a possibility the folks game me the wrong stuff.

Does anyone have any experience with pyrogallol and what form it generally comes in? I'm sure the folks that dispensed the pyro knew what they were doing but a little more certainty to ease my concern would be of benefit to me. Thanks in advance for your responses.

colivet · Aug 13, 2007

Usually pyrogallol turns yellowish when wet. Take the tip of a spoon of the powder and put a drop of water an see what happens. I am no chemist but that is what I would do.

pgomena · Aug 14, 2007

That which I've used is a light tan powdery/crystalline substance, a very funny texture. It is easily airborne, which why you should use a dust mask while mixing it or do it outdoors. Breathing the dust is not good.

Peter Gomena

Donald Miller · Aug 14, 2007

Mine is a fine powder. It has been reported that for that reason one should avoid inhaling the possible airborne dust.

Snapshot · Aug 14, 2007

Well, it seems I have pyrogallol. I was concerned that I was given the wrong chemical by mistake. Thanks for helping me out.

eclarke · Aug 14, 2007

Be careful with the pyrogallol. I can literally swim in Metol with no ill effects but the first time I used the pyro with my normal handling techniques (gloves, mask) my skin broke out and I had a rash for a couple days..Evan Clarke

Snapshot · Aug 14, 2007

eclarke said:
Be careful with the pyrogallol. I can literally swim in Metol with no ill effects but the first time I used the pyro with my normal handling techniques (gloves, mask) my skin broke out and I had a rash for a couple days..Evan Clarke

Good idea. It's my understanding that it's quite poisonous. What kind of mask did you use? I know that nitrile gloves are recommended and I've been using them. However, I have an inexpensive standard dust mask. Should I spring for a more expensive model?

eclarke · Aug 14, 2007

I used a regular 3M dust mask. My skin broke out, face, neck and arms. I mix it outside now instead of the darkroom and it's a large darkroom..Evan

Pyrogallol: Crystalline, Very Fine Powder or Both?

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