silver in film

[Mike Riches]

Hi

OK all you black & white shooters out there .

I need to know how much silver is in a roll of film ?

Its a question our safety guy at my school asked

Thanks in advance.

 

[haempe]

If I remember correctly around 1/4 g per roll...
this is just a vague value from memory, maybe someone has more accurate data...

 

[sevo]

The figures I remember from times when I was recovering silver from my fixer/blix were around 1-5g per square metre depending on the film type and brand - more (up to 15g) for colour film and for some films (lith, x-ray) usually not sold in rolls. There are approximately thirty rolls to the square metre, so even in the worst case, fast colour film, that is about 0.5g per roll. And more like 0.2g or less for modern black and white films - of which only about 75% will end in the fixer for average exposed subject matter.

 

[sepiareverb]

Its a question our safety guy at my school asked

This doesn't sound good.

I'd let him know how much silver you have in your teeth also, perhaps you can be put on disability.

 

[mwoenv]

Here's a good reference on silver in photographic processes:

http://www.kodak.com/ek/uploadedFiles/J210ENG.pdf

If the question has been raised with respect to what you can discharge to the sewer, the document in this link is useful with respect to discharge to public sewage tratment plants which sometimes have limits on the concnetration or amount of silver you can discharge to them:

https://www.pmai.org/WorkArea/linkit.aspx?LinkIdentifier=id&ItemID=7040

Call your local sewage treatment plant to see if they have an industrial pretreatment program which could contain limitiations on silver.

However, in general, the concentrations and amounts of silver are negligible unless you are operating a large lab.

 

[rpsawin]

Hi

OK all you black & white shooters out there .

I need to know how much silver is in a roll of film ?

Its a question our safety guy at my school asked

Thanks in advance.

At the very least It will vary based on format/length and type of emulsion. Certain "old school" type films have a higher silver content than modern type film. You may be able to find this info out by contacting the manufactures.

 

[Photo_Smith]

A troy ounce of silver (31g) is enough to make 5000 35mm colour films.
(source Kodak)

 

[sevo]

A troy ounce of silver (31g) is enough to make 5000 35mm colour films.
(source Kodak)

That would be too low, in the Kodak paper linked further up they claim that about 48 troy ounces can be recovered from 5000 rolls of Kodak Gold. It is more plausible as a figure for the silver loss, i.e. the silver remaining in the film, washed away or otherwise not recoverable.

 

[Photo_Smith]

That would be too low, in the Kodak paper linked further up they claim that about 48 troy ounces can be recovered from 5000 rolls of Kodak Gold. It is more plausible as a figure for the silver loss, i.e. the silver remaining in the film, washed away or otherwise not recoverable.

That figure is directly from Kodak quoted in Robert Shanebrooks book 'Making Kodak film' on page 35.

It would I'd think be a pretty accurate estimate that each tabular film would contain about 0.05g of silver which is a figure quoted to me by Kodak research when I visited on 2004.

Your figure would place 1.5kg of silver in 5000 films which would mean the raw silver cost in 5000 films at around $1000.

I guess your figure could be right, in which case each film would have about 0.25g of raw silver.

 

[Bill Clark]

There are a lot more chemicals that could be considered unsafe stored under your sink and/or out in your garage. I can name a few if you're interested.

Doesn't answer your question but sometimes folks need to turn the media off. They're trying to get the most eyeballs which reflect what they can charge advertisiers.

However, you can call your sanitary sewer people and/or find a pdf that determines what is hazardous, concentrations, and what you need to do. AG (silver) recovery seems to be the item of concern.