Pyrocat HD in Glycol shelf life

[Cor]

I find a magnetic, heated stirrer very handy:

http://www.keison.co.uk/stuart_cr302.shtml

This is a realy fancy one, but if you are patient and look at the usual places you must be able to find a cheaper (second hand) example.

Best,

Cor

[Ed Richards]

I would seriously weight the incremental benefit of mixing it yourself against the potential risks of introducing seriously toxic chemicals into your environment. I would at least mix it outdoors, rather than in the darkroom.

[Kirk Gittings]

Even though the OP of this thread was a false alarm, I'm interested in maximizing shelf life so there are no surprises-so the HDC version is especially attractive and it is not available commercially. So I would really be mixing it just once a year at most. Which of the ingredients are so toxic?

[Richard Wasserman]

Pyrocatechin is the one you need to worry about, especially in its powder form. You don't want to breathe it which should become obvious if you smell it—it's not pleasant. Not that I recommend that you stick your nose in it... Work neatly, wear a good particulate respirator, and have good ventilation—outdoors isn't a bad idea. Once it's mixed the breathing issue goes away. Wear Nitrile gloves if you're putting your hands in it, otherwise don't drink it or bathe in it and you'll be fine,

[Jim Noel]

Pyrocatechin is the one you need to worry about, especially in its powder form. You don't want to breathe it which should become obvious if you smell it—it's not pleasant. Not that I recommend that you stick your nose in it... Work neatly, wear a good particulate respirator, and have good ventilation—outdoors isn't a bad idea. Once it's mixed the breathing issue goes away. Wear Nitrile gloves if you're putting your hands in it, otherwise don't drink it or bathe in it and you'll be fine,

Pyrocatechin is certainly the most toxic in the formula, but the wearing of a dust mask and care in adding the powder to the liquid will prevent any problems. I have been mixing my own pyrocatechin and pyrogallol developers since the 1940's with no health problems resulting. Carefully dip the spoon in the powder and place it very low above the weighing paper so you don't cause the very light powder to become airborne. Do the same when moving the powder from the scale to the liquid.

By the way, many who warn against the use of these chemicals mix their own developers using hydroquinone which is at least as toxic.