Safe disposal of chemistry (especially fixer)

[macandal]

I'm getting ready to begin developing my film at home (mainly 4x5). My question is, how do I safely dispose of fixer, mainly, and if there are any other chemicals (in the developing process only) that I should also be concerned about their proper disposal. I ask this because the place where I have been developing film until now, they also don't allow people to dump the water you use to wash away the remaining fixer. This also goes in a special container, and they also don't allow people to dump the washing agent down the drain. This also gets collected in the receptacle where the water used to wash away the fixer goes.

Anyway, how do I properly dispose of fixer? And is fixer the only chemical I should worry about or is there anything else?

Thanks.

 

[MartinP]

You can almost certainly ignore what is actually chemically safe or sensible.

The thing you should comply with are your local laws which will be much, much stricter than is actually required - the reason for compliance being that you can probably get a large fine by not following the regulations, however excessive they may be. Some part of your local government will have a PDF file, or a human, that will answer your questions.

Bearing in mind that the largest component of your leftover chemistry will be water, one approach is to let it evaporate. This reduces the volume and weight of your problem considerably.

 

[macandal]

You can almost certainly ignore what is actually chemically safe or sensible.

I don't understand what you mean?

The thing you should comply with are your local laws which will be much, much stricter than is actually required

I'm pretty sure my local laws would tell me don't dump fixer down the drain...

 

[removed account4]

hi mario

i guess what martinp was suggesting is that photochemicals are benign and one should be able
to dispose of them with your drain, since you dispose of other household "stuff" that way,
but the local laws don't permit that.

usually municipalities have a household waste disposal day and if you save your chemistry you can
most likely dispose of it there. call your local water/sewer commission and i guess they will give you
what is OK and NOT-OK to put down your drain. in a lot of places as long as you mix everything but your fixer together
it neutralizes it all, and along with a big sink full of water it can go down the drain, but in some places it is not like that
so you need to find out ...

if you want to get the silver out of your fixer before you either have someone pick it up or you bring it to your household waste disposal place
you can easily reclaim most if not all the silver from it. there are a few simple ways to do this ...

you could use steel wool .. it will remove the silver and replace it with iron at a molecular level .. but then what do you do with the steel wool
and the sludge .. its kind of messy i guess. i used to do this with copper flashing, before it became expensive .. it was easy.

another way is through electrolysis. i sell small inexpensive devices that will electroplate the silver out of your well spent fixer. it has to be well spent
( used over and over ) but it will remove the silver, all but maybe 50-55 parts / million ...
if your fixer isn't well spent, well it will burn out the magnet, smell bad and it will turn black.

there is also something i sell called a trickle tank. its just like using steel wool, but it is self contained in a media bucket so there isn't any mess
if used correctly, you can remove most of the rest of the silver from your fixer ( and wash water! )
you can run it through 2x and maybe get your chemicals down to around 1 or .5 parts / million ...
you can then dump off your spent fixer with the household waste and make $ off the silver you removed.
i'm not into the hard-sell, but if you want to learn more about this stuff, i will be happy to help you out.
http://www.nanianphoto.com/silvermagnet.pdf

have fun figuring out what to do, cause you're gonna hear a lot of opinions

good luck !
john

 

[MattKing]

This might help: http://www.sunsetscavenger.com/hazardousWasteFacility.htm

I would talk to them as well.

And I bet Matt (tjaded here on APUG) would have some perspective on this.

By the way, it would be great if threads like this had a location in the title, because the rules on this are location specific. For example, there are no restrictions imposed in my area on down the drain disposal of small volumes (home darkroom size) of standard darkroom chemicals.

For clarity, I would include selenium toner among the chemicals that should be handled carefully.

 

[MartinP]

You have to follow the local regulations, which may possibly depend on disposal volumes. It is an option to lobby to have them changed or to move your location. You have no other legal options.

The main chemical used in rapid fixers is also used in swimming pools. Various silver compounds were used as a wound disinfectant before antibiotics. Beyond normal precautions, as written in the product information, don't worry about the standard chemistry - just keep yourself out of trouble by following the local rules.

Good point about selenium toner, and a few other less common toners. These tend to be more unpleasant than the regular chemistries. Don't try evaporating these toners out, as the dust will be more problematic than the liquids. However, do note that selenium toners can be used, with replenishment and filtration, for a very long time.

 

[removed account4]

You have to follow the local regulations, which may possibly depend on disposal volumes. It is an option to lobby to have them changed or to move your location. You have no other legal options.

The main chemical used in rapid fixers is also used in swimming pools. Various silver compounds were used as a wound disinfectant before antibiotics. Beyond normal precautions, as written in the product information, don't worry about the standard chemistry - just keep yourself out of trouble by following the local rules.

Good point about selenium toner, and a few other less common toners. These tend to be more unpleasant than the regular chemistries. Don't try evaporating these toners out, as the dust will be more problematic than the liquids. However, do note that selenium toners can be used, with replenishment and filtration, for a very long time.

martin

ammonium thiosphate is not used in swimming pools, it is used as fertilizer, sodium thiosulfate ( HYPO ) was used in swimming pools ...
but not much anymore ... you may be hard pressed to find a swimming pool supply place to sell you hypo crystals.

 

[Doremus Scudder]

You don't tell us where you are...

Most municipalities in the U.S. allow small amounts of photochemicals to be discharged into the municipal sewer system, i.e., hobbyist amounts. Larger users, such as photofinishers are subject to other regulations. Check with your city and see.

Some practical advice. Normal developers and stop baths are relatively benign. You can safely dispose of them into a sewer system (even a septic system in reasonable amounts). Notwithstanding, you should check your local regulations.

Fixer with lots of dissolved silver in it is the real problem (unused fixer is fairly benign and you can dispose of it in the sewer system).

There are a couple of ways to deal with silver-rich fixer:

If there is a photofinisher in your area (they are getting harder to find), you can take your spent fixer to them. They will likely take it for free because they reclaim the silver from it and make a bit on it. That's what I used to do till photofinishers disappeared in my area.

If your volume warrants it, you can get one of John's silver magnets and do your own silver recovery. I do not own one, but have heard good things about them. After silver recovery, fixer can be disposed down the drain.

If your local regulations allow, you may be able to dispose of small amounts of used fixer into the municipal sewer. This is, unfortunately, what I have been doing lately. It's legal, but I'd really like a better solution. But, my U.S. darkroom activity only produces 5-10 gallons of used fixer a year; not that much.

Lastly, you can collect your fixer and take it to the hazmat facility in your area. I used to do this, but became convinced that the fixer would never make it to silver recovery due to the ineptness of the hazmat facility personnel. They simply dumped it into a large drum labeled "photo chemicals" (even though I told them it was fixer and needed to go to silver recovery...). It's likely still sitting in that drum somewhere at a waste depot.

Evaporation and disposing later at a hazmat facility is another option.

Best,

Doremus


www.DoremusScudder.com

 

[Ian Grant]

Having been in the trade - precious metal recovery and photographic effluent disposal - I totally agree with Doremus,

We were licenced to carry and dispose of Developer, fixer, Bleach, bleach fix etc, on an industrial scale the silver's removed then the dev & fix etc mixed as that neutralises the alkali dev with the slightly acid fixer then the whole lot discharged to the sewer. The water board (UK) stipulated the discharge volumes/rate so that they knew their sewage treatment works could cope.

We also fitted silver revery units and the water boards actually preferred smal scale licensed disposal from labs straight to the sewer as that meant far greater dilution. They weren't interested in small (home) darkrooms although technically they were covered by the same regulations.

Ian

 

[Neal]

Dear Mario,

The city of South San Fransico (I don't really know if it is in your area) has a drop off site. There should be a site like this available to you.

Neal Wydra

 

[fotch]

.........................
if your fixer isn't well spent, well it will burn out the magnet, smell bad and it will turn black.

.....................

good luck !
john

Can you elaborate on this? How much do you have to reuse it to be "well spent" ?
How can you tell?
How likely is it that your going to burn out the magnet?

 

[MartinP]

martin

ammonium thiosphate is not used in swimming pools, it is used as fertilizer, sodium thiosulfate ( HYPO ) was used in swimming pools ...
but not much anymore ... you may be hard pressed to find a swimming pool supply place to sell you hypo crystals.

Absolutely right, sorry about that. I mixed up my fixers, Sodium thiosulfate is the 'old fashioned' stuff, as used by Ansel Adams etc.

 

[Mr Bill]

...( used over and over ) but it will remove the silver, all but maybe 50-55 parts / million ...
if your fixer isn't well spent, well it will burn out the magnet, smell bad and it will turn black.

Can you elaborate on this? How much do you have to reuse it to be "well spent" ?
How can you tell?
How likely is it that your going to burn out the magnet?

fotch, in the line above your quote John mentioned about 50 parts per million (~ 1/20 gram per liter) of silver as a lower limit on how far the "magnet" can go. So any silver content higher than this can likely be plated out.

I've never used the Silver Magnet, but have quite a bit of silver recovery experience. The idea is that an electrolytic silver recovery system must keep it's plating current below the point where "sulfiding" occurs (this is when the plate turns very dark). Many people call this a "burned plate," although it's not really burned, it just has that appearance. Anyway, as silver is removed from the fixer, the allowable current limit gets lower and lower. If you don't know when to quit, you'll cover the cathode with silver sulfide, which inhibits further plating.

I'm sure you won't really "burn out" the Magnet's power supply, but you could possibly cover the insides with enough silver sulfide to prevent further plating. My understanding is that the Magnet has some LEDs to indicate the status of plating, so normally there should be no problems. If I'm wrong about any of this, I'm sure John can correct me on it.

 

[removed account4]

hey mr bill !

thanks for chiming in while get accurate numbers from
the folks that make the magnet ..

hi fotch, mr bill is 100% right on ..
according to the folks that make the magnet
it requires that you have at least 100ppm ( parts / million )
of silver in the fixer. i am sure it can run with lower concentrations
( above the 50-55ppm end-point ) but it runs more efficiently with high concentrations.

as mr bill said, it won't burn out the power supply, but it will leave you with a black smelly useless cathode
if you run it without high enough concentrations of silver in the fixer. it doesn't happen very often, but once in a while
i get an email from someone who forgot to use spent fix, and instead used 1-shot fix ... and it rendered the magnet useless.

there are test-strips available to see how much silver is in the fixer, but the clip test can be accurate enough.
for film fix double the clear time and split it between 2 baths, and when it takes double the initial unused fix clear time
it is time to desilver the fixer. make bath #2 your new bath #1 and make a fresh bath for #2 ...
a lot of people are kind of freaked out buy using the fixer to capacity, but it is pretty safe, seeing you have a second bath that is always far from
being spend.

if shot fix is your thing, the whole ion transfer de-silver method might work well in your situation ... it works with low concentrations of silver ( 1 shot fix, wash water &c ).

john