Recycle aluminum plates, negatives and any other silver laden paper. Image Processing Silver compounds are classified as hazardous wastes under state and federal law if liquid wastes exceed five milligrams per liter of silver at a pH of 5.0. If process baths are discharged into the sewer, a permit by the local sanitation department is usually required. Concentrations of silver-contaminated wastewater must be maintained below the limits established by the sewer authorities. Ways to Manage Silver Eliminate it by using silver-free films.
Some silverless products are vesicular, diazo and eletrostatic films.
Photopolymer films contain carbon black as a substitute for silver. Recover silver from fixing baths and have a commercial recycler pick it up. Purchase a silver recovery unit and perform the recycling of fixer on premises. Add ammonium thiosulfate to silver contaminated baths to extend the allowable buildup of silver. Process Baths Use an acid stop bath prior to the fixing bath.