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University of Colorado Denver

Environmental Health and Safety, University of Colorado Denver

Compliance Assistance

Photo Developers

Silver Recovery Unit
​Throughout the University of Colorado Denver | Anschutz Medical Campus photo developer units are used in various departments and laboratories to process images.  Chemicals, the discharge from the processing units, and even certain waste films are regulated by the Colorado Department of Public Health and Environment (CDPHE) and the US Environmental Protection Agency (EPA) under the Clean Water Act (CWA) and Resource Conservation and Recovery Act (RCRA).  To ensure that your research and academic activities on campus are not interrupted due to regulatory oversight, please ensure that your image/photo processing operations adhere to the procedures set forth by the Environmental Health and Safety (EHS) department.  Register your units through EHS, use a silver recovery unit, and properly manage waste chemicals, films, and papers.  The information below is provided for the general campus community.  For more information please contact Environmental Health and Safety at 303-724-0345.

 Photo developers

Photo developers develop photographic images or print media using chemicals.


 The importance of proper silver disposal

  • ​If you use fixer or similar solutions in a photo developer or in a darkroom as part of your duties at UC Denver, then you are discharging silver that must be recovered before it reaches the environment.  The silver in this process can be harmful to both humans and the environment.  Even at low concentrations, silver can adversely affect aquatic life.
  • This document provided below discusses why the requirement exists and takes you through the steps of setting up and maintaining a silver recovery system.

 Record keeping

  • Record keeping is essential for properly documenting and managing your chemical processors in accordance with regulatory requirements.  You must keep certain records and should be able to present these during inspections:
    1. The date the silver recovery unit filter was changed or its discharge tested.  Verification can be the invoice for the filter and/or service.  Dating the filter canister helps track this.
    2. The date the contracted service provider conducted maintenance on the unit.  Documentation can be the invoices/bills as long as those specify date of service.
  • Other important information to document includes:
    1. Department responsible person (and alternates if applicable) for the unit
    2. Service provider name
    3. Equipment location
    4. Make and model of the unit
    5. Hazardous waste disposal methods used (as applicable)
  • Provided below is a log sheet to track the dates of maintenance and silver recovery unit change out.  When the log sheet is full print out a new copy, staple the old one behind it and tape it back on the wall.  Please remember to write the name of your contracted service provider on the new log sheet.
  • Please have your contracted service provider fill the log out when they perform such services.  The log must be hung up on the wall in the photo developer room.  This will allow the Environmental Health and Safety auditor to collect this information without having to do a face-to-face audit with the person responsible for the unit.

 Proper chemical disposal

  • ​Do not pour chemicals used in the photo developer process down the drain
  • If you need to dispose of a chemical, or have any questions regarding proper chemical disposal methods please contact the Hazardous Waste Group
  • If you are managing the chemicals yourself, you need to ensure that you are properly disposing of fixer and other chemicals that cannot go down the drain without treatment/filtering.

 Contracted service provider

​Most researchers are using a contracted service provider for the management of their photo developer processing units.  The contractor provides services that include:

  • Chemical testing and refills
  • Equipment maintenance cleaning
  • Installation and changing of silver recovery units (filters that re required when discharging chemicals directly to sanitary sewers such as floor drains or sinks)

List of contracted providers on campus (AMC):

  • Medical imaging Technologies
  • Merry X-Ray
  • Rocky Mountain Radiographics
  • T.G X-Ray

If you do not use a contracted service provider and are managing your own chemical processes, please contact EHS for guidance to help you meet your regulatory requirements.

  • Christina Aguilera, Environmental Compliance and Industrial Hygiene Manager, 303-724-0242



 Recommendations and tips

  • ​The recommended standard for maintenance to the unit is once per month
  • The recommended standard to change the silver recovery unit is once per year
  • When your contracted service provider is conducting maintenance on the unit, ask them to check the silver recovery unit to see if it needs to be changed sooner than its next scheduled date.  Also remind them to fill out the log sheet when any maintenance or silver recovery unit change out is done to the machine
  • Make sure there is an emergency contact card outside the photo developer room.  This way if there is a spill or other emergency, the contact person will be informed by Facilities Management personnel
  •  If the P.I or the lab manager is no longer responsible for the machine, please contact Environmental Health and Safety so that the information can be updated

For more information on photo developer requirements, visit the following:


 Decommissioning a darkroom or photo developer

​EHS and your Silver Recovery vendor should be notified when decommissioning or moving a photo developer from a UC Denver building.  Facility Managers should report all new or relocated darkroom and photo developers to EHS at (303)-724-0345.9

 Registration form

​If you have a new unit, you must register it with EHS.


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