Chemicals Lifespan

[steve_johnston9]

<p>Am looking to start developing my own film at home. I have heard it mentioned that the chemicals have a limited lifespan. How long is this ? Also what is an environmentally good way to dispose of the chemicals afterwards ?</p>

[mauro_franic]

<p>What film and chemicals will you use?</p>

[Alan Marcus]

<p>First about chemical disposal:<br>

A home darkroom, not a commercial business, need not worry about chemical disposal. This is because, despite what you read and hear, photo chemicals are reasonably benign. That being said, sometimes-local sewer codes at set to impossible or perhaps impractical limits for some of ingredients. Best to check with your local sewer authority.</p>

<p>The shelf life of photo chemicals are all over the map. Most liquid and power concretes are good for years if the packaging has not been disturbed. As a general rule, from concentrates we make a stock solution by dilution with water. If stored in sealed bottles, stock solutions are good for several months. For use, we further dilute the stock solutions with water to make a working solution. Now the life of a working solution is measured in days and hours.</p>

<p>Some tips:<br>

Shelf life for mixed solutions is best if the container is glass. Polyethylene bottles are generally OK . Bottles should be brown or green as these curb reactivity to light. Squeeze plastic bottles to avoid an air space in the container. Glass marbles added to a glass bottle will diminish the air space. Most photo chemicals, especially developers oxidize over time. Developers are derivatives of benzene and when oxidized, revert to coal tar. Note the color of all solutions when fresh. If a color change is noted or precipitates form, then down the drain. It is wise to always use fresh chemicals. It is wise to test stored chemicals if the work is important. </p>

[cricketprints]

<p>If you have a local mom & pops photo lab (not Walgreen's/CVS) they should be happy to take your used fixer & stab for proper silver recovery. </p>

[walter_degroot]

<p>alan is right on.<br>

everything has some anti-enviromental problems.<br>

even back in cave man days. ( no toilets or clean water systems)<br>

there are a few photo chemicals -- that you are unlikely to use-<br>

like chomoum intensifier and some toners-<br>

that are hazardous both to you and the enviroment.<br>

I do not know if they even still exist.<br>

Once color solutions were a hazard,. but Kodak changed and improved processes to eliminate thewse chemicals. They realized that folks often did not take proper steps to<br>

dispose of these things.<br>

Older alkaline batteries were previously tossed in the trash<br>

neder ones, with the pine tree sybol are safer to dispose.</p>

<p> </p>

[craig_shearman1]

<p>B&W chemicals like Kodak D-76 film developer, Dektol paper developer and either Kodak Fixer or Kodak Rapid Fixer are definitely good for 2-3 months once mixed. I've used six-month old chemicals without bad results. Key thing to look for is when the developer starts to turn brown rather than just slightly off clear. As for disposal, it all just goes down the drain. You don't want to drink the stuff but there is no environmental hazard involved, certainly far less than the phospates, etc., in the rinse water coming out of your washing machine or dishwasher. Color chemicals are more complex but again not an issue in the quantities you're likely talking about. Do not go asking your local sewer authority what's OK -- that would only put you on their radar screen for complying with regulations that are intended for industrial or commercial entitities. And I would be extremely surprised if any local lab would want to be bothered with disposing of your chemicals. First of all it isn't necessary and there isn't enough silver involved short of commercial quantitites to make it worth the trouble. Secondly if they are big enough to be regulated by local authorities, then putting anything into their waste stream from a third party just increases the risk that they'll get cited for putting something down the drain they weren't supposed to.</p>

[larrydressler]

<p>Fixer last a long time after mixed and stop bath too it is the developer that goes bad quickly. I use HC-110 and rodinal highly concentrated liquids and mix them one shot right from the concentrate. I I put them in smaller plastic bottles and then put rubber caps on them designed to use a medicine syringe. I suck out the amount I need mix with water and develop.</p>