View Full Version : Pollution/Pyro?

23-Apr-2012, 02:24

I bet this has been covered before but:

Now that I'm not using my kitchen as much for film development, I'm considering Pyro.

I know that it's toxic as powder, less toxic as liquid.

I'm just wondering, if after I use it, if I flush it down the drain, is it something that's going to cause problems downstream? I'm using XTOL currently and I'm pleased with the results. So I don't have to switch. I wouldn't feel good adding more shit to the water supply, no matter what the results.


Ken Lee
23-Apr-2012, 04:36
Many household cleaners are corrosive and toxic. The birth control hormones and antidepressants excreted daily into the water supply constitute a far bigger problem, I suspect.

Pyrocatechin is/was used to dye people's hair brown, among other things. A few liters of it is probably nothing compared to what leaks out of a typical automobile. I've often wondered: where does all the rubber go, from the millions of tires that "wear down" every year on the road?

My view is that if you were operating on an industrial scale, it would be worthy of serious consideration. A few liters here and there are inconsequential compared to the rest of what our households put into the water supply, and the toxic plastic which wraps all the things we buy and then goes into a landfill or is burned in an incinerator.

What is XTOL composed of: 4-Hydroxymethyl-4-methyl1-phenyl-3-pyrazolidone?

How safe is it to drink that? :cool:

Jay DeFehr
23-Apr-2012, 07:51

These compounds oxidize and break down pretty quickly. Not an issue at household scale.

23-Apr-2012, 08:01
Followup question:
What would happen in a household septic system? We live in the woods and have a septic system. Would it be best for me to save developing chemicals and take them to a proper waste disposal facility?
Thanks for your answers.


Doremus Scudder
23-Apr-2012, 08:10
Pyrogallol and pyrocatechol break down rapidly in water-treatment plants and septic tanks. No need to worry about polluting the environment with them, or most developers for that matter.

The real pollutants from black-and-white processing come from the fixer and selenium toners. Silver in the fixer and unused selenium from tone dumped before exhaustion collect and concentrate in sludge in water-treatment facilities. They are not bio-degradable. I recommend silver recovery where possible and replenishment and re-use of selenium toners.

And, don't empty used fixer into a septic system. Silver will kill off the bacteria over time. A little now and then wouldn't hurt much, but if you dump a lot of used fixer into a septic system, then you may destroy it's ability to break down the waste.

My darkroom in Oregon is on a septic system. I dump developers and stop baths (mixed together first to neutralize a bit), but take the fix to silver recovery or, at least, to the municipal sewer (photo labs with silver-recovery systems are getting harder to find, and, lately, I have the feeling that the hazmat facilities don't get the fixer to silver recovery either...).



23-Apr-2012, 13:01
Thanks! I knew about silver in fixer and will treat it accordingly. It's good to know that minute quantities of developer are not a problem.


J. Fada
23-Apr-2012, 20:10
If I am not mistaken, if you are concerned about polluting with Pyrogallol than don't pee in the toilet either. :)

In other words, don't worry about it.

Drew Wiley
24-Apr-2012, 08:42
I think there would be real issues with tanning developers on an industrial scale, hypotehtically for instance, if all of a sudden someone was going to start up processing lots and lots of true Technicolor movie film. Pyro solutions also have certain medical application in labs which are EPA monitored. I had a friend in charge of EPA inspections in
this area and he said home darkroom aren't even on their radar. Perhaps the most damaging chemcials put down the drain around here (coastal) are household and driveway surfactants like Simple Green. Despite being nontoxic per se, they kill aquatic life like crazy by smothering gills, even at extreme dilution.

24-Apr-2012, 15:16
Ok, thanks guys. Maybe I'll give it a try.

And buying it in liquid form and using it in my studio (which is next to my bedroom) should be safe enough as long as I keep it off me?

I'm afeard because my testicles are pretty small already.