The keys to pollution prevention in the printing industry are material substitution, ink recycling, and minimization of changeover. Below are some recommendations for good operating practices.

• Segregate spent fix baths segregated from rinse waters and developer solutions. Silver recovery is more efficient on the more concentrated spent fix waste stream.
• Optimize bath life and reduce wastewater quantity by adjusting chemical replenishment rates and wash water flow rates on photoprocessor.
• Keep lids on bulk solutions to prevent oxidation and contamination while in storage.
• Use materials on a first in, first out basis so as to not exceed shelf life and thus reduce waste. Do not get rid of expired products by discharging to wastewater treatment system.
• Purchase ink from distributors that will take back unused or spent ink.
• Special non-drying aerosol materials can be sprayed on ink fountains to keep them from drying out overnight. Fewer ink fountain cleanings will be required.
• Purchase new developing machines that use less rinse water and have squeegees or air blades to reduce dragout from chemical baths to rinse water.
• Add acetic acid to the fix bath. This keeps the pH low, maximizing soluble complexes and extending bath life.
• Recycle inks to make black inks or filter out inks instead of discharging to sewer.
• Change from alcohol based to water based inks and aqueous type cleaning agents.
• Save rinse water and transfer to an ink splitting device that absorbs the various ink pigments on a cellulose-based porous material. Then the nearly clear filtrate may be permitted to flow to the sanitary sewer. (First check with your local sewer authority for authorization.) The pigment-colored cellulose can be sent along with other wastes to the local landfill.

Benefits of water based inks and cleaning agents:

• Reduce solvent emissions by 80% or more.
• Reduce toxicity of liquid and gaseous wastes by approximately 90%.
• Wastes that were previously classified as hazardous can be recycled or disposed of as nonhazardous, thus saving disposal costs.
• There is no difference in raw material costs for inks and cleaners, productivity may increase, no capital expenditures are required, insurance costs may decrease and nondisposable wiping materials provide a savings.

For more information, visit the following pages in the VA SBAP web site:

Fact Sheets & Guidance Material: P2 Fact Sheets & Libraries

Resources By Industry Sector: Printing & Photoprocessing index

SOURCE:
The Virginia Office of Small Business Assistance would like to thank the Alabama Department of Environmental Management, Pollution Prevention Unit for the use of this fact sheet. The information for this fact sheet was obtained in part from Ink and Cleaner Waste Reduction Evaluation for Flexographic Printers EPA/600/SR-93/086 July'93