Photo-processing wastes may contain silver which is considered a toxic heavy metal by the Environmental Protection Agency. The silver is primarily present as soluble silver thiosulfate complex. Silver sulfide is present in smaller amounts. Depending on the stage from which the waste originates and the type of film processed, the silver concentration can range between 5 mg/L and 12,000 mg/L. Therefore photo-processing solutions and spent rinse waters are classified as hazardous wastes. In addition to photo-processing solutions and spent rinse waters, films and negatives may contain high silver concentrations and require management as hazardous wastes.
It is illegal to dispose of hazardous wastes via drains, normal trash, or any other means which would result in a release to the environment or discharge to the city sewer system. Photo-processing solutions and spent rinse waters must either be collected and sent to Environmental Health and Safety (EHS) for disposal or processed to remove the silver before drain disposal. All films and negatives must be collected and sent to EHS.
For photographic waste such as used solution and treated paper, EHS must make a hazard determination for proper disposal method. Disposal depends on the particular process and the material’s characteristic. It should be assumed that the waste solution and treated paper exhibits the same Hazardous Waste Characteristics as would the chemical applied to it.
If you have a photo-processing area and would like to EHS perform a hazard assessment of your waste or have a silver recovery unit installed, please call EHS at x81450.
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