Even when not required by environmental regulations, the following best practices are recommended. In some instances, best practices presented here are actually required by regulations.
Silver Recovery Options
Processing spent developer/fixer (and other silver containing material, for that matter) through a silver recovery unit can allow the material to be considered non-hazardous, however you should check with EH&S staff to determine your school's procedure on this issue. Some facilities have on-site silver recovery units, while other facilities contract this to a licensed contractor. Using a silver recovery process may save you money and allow you to avoid handling many materials used/produced as part of the photo developing process as hazardous waste. Suitable recycling methods include:
Off-site Silver Reclamation Facility - Developer/fixer disposal can be handled through an off-site silver reclamation facility that is licensed to accept hazardous waste. Make certain you obtain the appropriate copies of the manifests and any certificates of reclamation for shipments sent to these companies.
Operate your own silver recovery unit - Purchase and use your own silver recovery unit on-site. Operating this type of unit will require certain regulatory requirements. Make certain that the concentrations of silver in your recovery process waste are allowable to be discharged to the local sewer system.
Acid is used in photo developing stop bath solutions. For safe acid storage and handling, adhere to the following:
Always store acids in a cabinet for which the material of construction is compatible with acid.
Working with acid should always take place in an acid hood with adequate ventilation.
When mixing stop baths, always add acid to water and not water to acid.
Utilize and have available the proper safety equipment/devices such as eye protection, emergency eye-washer and shower.
Waste Handling and Disposal
Best practices or regulatory requirements related to waste handling and disposal include the following activities:
Perform regular housekeeping activities in waste storage areas.
Reuse or recycle materials whenever possible.
Inspect waste management areas for spills and waste management containers for leaks.
Track waste generated, evaluate the process generating the waste and look for ways to reduce waste generation.
Characterize waste streams.
Find substitutes for harmful chemicals; properly dispose of unusable chemical inventory.
Segregate and separate wastes.
Do not dispose of liquid wastes such as oils or hazardous materials into dumpsters or drains.
Maintain adequate supplies of spill response equipment and materials in accessible locations near areas where spills may be likely to occur.
Perform and document in a logbook periodic inspections of hazardous and non-hazardous waste storage areas.
Training employees in proper procedures to reduce your facility's impact on the environment is a best practice. More detailed training information is provided in the regulatory requirements sections of the tour. Employee training may include the following:
- Spill response training for personnel who handle hazardous materials,
- Right-to-know training to inform users of the dangers inherent to the hazardous materials being used, and
- Hazardous materials management.
Photo Development Process
- When mixing powdered developers, ensure proper ventilation (this is required by OSHA), preferably with a fume hood.
- Ensure good ventilation of the darkroom with between 10 and 20 air changes per hour.
- Wear gloves and goggles when handling photochemicals.
- To prevent evaporation or release of toxic vapors and gases, cover all solutions when not in use.
- Replace other highly toxic developers such as catechin, chlorquinol, or pyrogallol with less toxic developers such as phenidone.
- Keep hypo eliminators away from sources of heat.
- Read the updated Material Safety Data Sheets (MSDS) on all chemicals used in the developing of film. MSDSs must be available to employees at all times.
- Eliminate trip hazards by keeping containers off the floor.
- Do not store chemicals that may react with each other in the same area.
- Do not eat, smoke or drink in the facility.
- Using a pre-made liquid developer is safer than mixing powdered developers. If powdered chemicals must be mixed, do so in a fume hood or glove box.
- All darkrooms should have eyewash stations that connect to the water supply and use "hands-free" operation.
- Label containers of photochemicals.
- Neutralize any acid spills using a buffering agent prior to cleaning up with inert or other non-reactive adsorbents; use acid spill kits for small to medium size spills.
- Use a damp towel or sponge to clean up spills of dusts and powders.
- Photochemicals with a pH of less than or equal to 2 or greater than or equal to 12.5 (pH £2 or pH ³12.5) must not be poured down the drain.