Long story short (TLDR), you should ask an allied institution if you can simply add this to their on-site accumulate of used film for silver recovery. There should be plenty of those around the San Jose and San Francisco area; call up some colleagues and see if you can get a small favor. Adding one sheet to their stockpile should be essentially imperceptible to them. Unfortunately disposing of your one sheet on your own will be ridiculously expensive for the given volume, and the reason is that it is regulated at the city, county, state, and even federal level. Mainly this is because it has two concerns; 1) the nitrate- and acetate-based film is unstable, potentially flammable, and is considered hazardous, and 2) the silver it contains is toxic if it is released into the environment, particularly for aquatic life.
At the Minnesota Historical Society we have accumulated waste silver-based film on-site for many years, and when we reach a tipping point, we schedule with a recycling company to come and pick it up. Typically they only want certain types of film, and specifically this is related to how much silver can be recovered from it (not all types of film contain silver). We tried to dispose of some "thermal film" a few years ago and were told they did not want that as it contained little to no silver (it is simply non-hazardous solid waste). We are usually disposing of historic deteriorating 4x5 negatives made of nitrate- and acetate-based film, and also worn-out rolls of microfilm, though other formats may also be included in small quantities. A few years ago we disposed of a significant amount of deteriorating motion picture stock. Recyclers also typically want only clean film, with minimal to no packaging, envelopes, tape, plastic spools and the like, and it can take some time and effort to remove these materials before they will take it away. Once those are removed it should be possible for them to weigh your film, and that will generally tell them how much silver they can expect to recover from it. Unfortunately when the microfilm is removed from the spool it takes up a lot more volume, which may also trigger a disposal event.
Typically we have 2-3 drums we accumulate these in, which probably total 50-100 gallons of volume, and often weigh 50-200 pounds (depending on the volume and density of the film). Thankfully we have a dedicated hazardous waste storage room that vents directly out of the building, but even with that our fire inspector does not want us to have more than a couple hundred pounds on hand before scheduling a disposal event. If this stuff were to ignite (or possibly auto-ignite) it would cause a big problem as it burns amazingly fast, and typically cannot be extinguished before it burns completely, and can cause extensive damage to a building.
Recyclers used to pay us a few hundred dollars to take it away, because they could recover the silver and sell it for a profit. This whole process has become harder for us to do as it appears there are fewer recycling companies willing to do silver recovery. Part of the reason is since the demise of photographic film, there are fewer places disposing of silver-based film, and at this point it appears it is mainly museums and medical practices (old x-ray films) that need this service. My understanding is California is becoming one of the last holdouts of the silver recovery industry, due to the large filmmaking industry that was there. We accumulate waste silver-based film intermittently, but typically need to dispose of it about every ten years. The last few times we have had a recycler pick up they have taken it away for free, which is still better than having us pay to have it taken away, but the writing seems to be on the wall that in the future we may have to pay to have it taken away, and even then they may have to ship it to California as that may become the last holdout for some of these silver recovery firms.
Good luck and take care, Tom
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Thomas Braun
Senior Objects Conservator
Minnesota Historical Society
Minneapolis MN
(612) 824-6121
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Original Message:
Sent: 03-03-2023 15:57
From: Carolyn Schimandle
Subject: Hazardous waste disposal of one nitrate negative
I have one, only one, deteriorating nitrate negative to dispose of. I know it is HAZARDOUS WASTE. Does anyone know what type of hazardous waste facility I should get it to? Particularly, would a household hazardous waste site be able to handle it?
Sadly, our environmental safety person just left his job, and nobody has been able to answer the question for me. Everything online just says to dispose of as hazardous waste.
It's sitting by my desk in a buffered four-flap enclosure, and I'd really like to get it out of here and to the proper facility.
Carolyn Schimandle
Parks Program Coordinator for Interpretation, Region 2
Santa Clara County Parks
408-834-2397
Parkhere.org