As of April 30 2007, this document is NO LONGER IN USE by the World Bank Group. The new versions of the World Bank Group Pollution Prevention and Abatement Handbook Environmental, Health, and Safety Guidelines are available at WORLD BANK GROUP Effective July 1998 http://www.ifc.org/ifcext/enviro.nsf/Content/EnvironmentalGuidelines Printing The printing industry is very diverse, as can be varnish is sometimes added to the printed sur- seen in the multitude of different products that face. bear some form of printing—books, daily news- The printed matter is processed off-press, papers, periodicals, packaging, cartons, carrier where it is cut, jointed, folded, sewn, bound, bags, drink containers, signs, forms, brochures, packaged, and so on. advertisements, wallpaper, textiles, sheeting, Printing may also be a step in another manu- metal foil, and so on. facturing process—for example, laminating at Text, diagrams, pictures, and so on are de- package printing works, in which layers of pa- signed and composed on, for example, a news- per, plastic and metal foil are joined. paper page. If pictures and/or text are to be Plastic surfaces are treated to facilitate print- printed in several colors, these must be separated. ing using electrical discharges from an electrode The pictures are also often screened, producing system, the “corona treatment.” an image that consists of a large number of very small dots instead of a solid field. Photographic Waste Characteristics techniques are used for setting and working on pictures. Emissions into the air mainly consist of organic The page is then transferred to a printing form, solvents and other organic compounds. Some a printing block (high-intensity, flexography), substances may cause unpleasant odors or affect plate (offset), roller (rotogravure), or stencil health and the environment. (screen printing). This is done by means of expo- Discharges to water bodies mainly consist of sure to a light-sensitive coating. In the case of silver, copper, chromium, organic solvents, and offset and screen printing, the printing form is other toxic organic compounds. developed by washing away part of the coating; Noise comes principally from fans, printing the form may then, in theory, be used immedi- presses, and transport. ately. The offset plate is coated with rubber to Wastes consist of environmentally hazardous protect it from oxidation. The screen sheet’s sides wastes such as photographic and residual chemi- are masked with protective paint. cals, metal hydroxide sludge, dyestuff and sol- Other printing methods require further stages. vent residues, wiping material containing dyes The small grooves in the gravure roller are etched and solvents, and oil spills. There are also bulky or, increasingly, engraved, and the surface is wastes such as paper. chromed for better durability. The rubber print- ing block for flexographic printing is cast or en- Pollution Prevention and Control graved by laser. Printing is done on single sheets or paper web, The recommended pollution prevention mea- using one or more printing units, depending on sures are as follows: the number of colors required. The dyeing agent is, in most cases, a solvent that evaporates from • Estimate and control, typically on an annual the paper. (In some cases, it is necessary to has- basis, the quantities of volatile organic solvents ten evaporation by feeding in warm air.) Clear used, including the amount used in dyes, inks, 391 392 PROJECT GUIDELINES: INDUSTRY SECTOR GUIDELINES glues, and damping water. Estimate and con- • Return toxic materials packaging to the sup- trol the proportion that is made up of chlori- plier for reuse. nated organic solvents. • Recover plates by remelting. • Replace solvent-based dyes and glues with sol- • Label and store toxic and hazardous materi- vent-free or water-based dyes and glues, where als in secure, bunded areas. feasible. Water-based dyes are preferred for flexographic printing on paper and plastic and Treatment Technologies for screen printing and rotogravure. • Give preference to the use of radiation-setting Air Emissions dyes. • Engrave, rather than etch, gravure cylinders • Control emissions of gases from web offset to reduce the quantity of heavy metals used. with heat-setting thermic or catalytic incinera- • Enclose presses and ovens to avoid diffuse tion. Recover toluene from rotogravure by evaporation of organic substances entering the absorption, using active carbon. Carry out ad- general ventilation system, where feasible. Use sorption of solvents, using zeolites, and re- suction hoods to collect vapors and other fu- cover organic solvents. gitive emissions. • Treat organic solvents by using trickling fil- • Evacuate air from printing presses and dry- ters. Use biological scrubbers to treat dis- ing ovens into a ventilation system. charges of water-soluble solvents. • Where possible, replace chemicals used for • Treat metal-containing effluents from the form preparation and cleaning with more en- manufacture of gravure cylinders and print- vironmentally friendly alternatives. Maintain ing blocks by applying the established meth- a record of chemicals and environmentally ods of chemical precipitation, sedimentation, hazardous waste. Do not use halogenated sol- and filtration. Collect fixing baths for recov- vents and degreasing agents in new plants. ery or destruction. Evaporate solvents from re- Replace them with nonhalogenated substances generation of active carbon filters. Perform in existing facilities. closed-screen chase washing; recirculate sol- • Estimate the quantity of developing bath and vents and separate sludge. Fit developing fixing bath used per year and maintain these machines with counterflow fixing or connect at acceptable levels. them to an organic ion exchanger. Collect film- • Minimize the rinse water flow in the develop- developing agents for destruction. Carry out ing machines by, for example, use of “stand-by.” high-pressure water jet cleaning. Use ultrafil- • Collect fixing bath, developer, used film, pho- tration to treat washing water. tographic paper, and blackened ends of pho- tosetting paper and manage them properly. Solid Wastes • Use countercurrent flow fixing processes. • Aim for a closed washing system. Because of the relatively small volumes of solid • Store chemicals and environmentally hazard- wastes, it is difficult to find acceptable and af- ous waste such as dyes, inks, and solvents so fordable methods of disposal. Ideally, solid that the risk of spillage into the wastewater wastes should be sent for incineration in a facil- system is minimized. Examples of measures ity where combustion conditions (1,100° C and that should be considered are retaining dikes at least 0.5 second residence time) that ensure or areas with no outlet, as a means of absorb- effective destruction of toxics are maintained. ing spillage. Minimize noise disturbance from fans and presses. Emissions Guidelines • Use equipment washdown waters as makeup solutions for subsequent batches. Use counter- Emissions levels for the design and operation of current rinsing. each project must be established through the en- • Recover energy from combustion systems, vironmental assessment (EA) process on the ba- when they are used. sis of country legislation and the Pollution Prevention Printing 393 and Abatement Handbook, as applied to local con- ditions. The emissions levels selected must be Table 1. Effluents from Printing Plants justified in the EA and acceptable to the World (milligrams per liter, except for pH) Bank Group. Parameter Maximum value The following guidelines present emissions levels normally acceptable to the World Bank pH 6.5–10 Group in making decisions regarding provision BOD 30 of World Bank Group assistance. Any deviations COD 150 TSS 50 from these levels must be described in the World Oil and grease 10 Bank Group project documentation. The emis- Cadmium 0.1 sions levels given here can be consistently Chromium achieved by well-designed, well-operated, and Hexavalent 0.1 well-maintained pollution control systems. Total 0.5 The guidelines are expressed as concentrations Copper 0.5 to facilitate monitoring. Dilution of air emissions Silver 0.5 Zinc 2 or effluents to achieve these guidelines is unac- ceptable. Note: Effluent requirements are for direct discharge to surface All of the maximum levels should be achieved waters. for at least 95% of the time that the plant or unit is operating, to be calculated as a proportion of at noise receptors located outside the project annual operating hours. property boundary. Air Emissions Maximum allowable log equivalent (hourly The maximum value for emissions of volatile measurements), in dB(A) organic compounds (VOCs) should be below 20 Day Night milligrams per normal cubic meter (mg/Nm3), Receptor (07:00–22:00) (22:00–07:00) calculated as total carbon. Chlorine (chloride/ Residential, chlorinated hydrocarbons) emissions should be institutional, below 10 mg/Nm3. educational 55 45 Industrial, Liquid Effluents commercial 70 70 The effluent levels presented in Table 1 should Monitoring and Reporting be achieved. Frequent sampling may be required during start- Solid Wastes up and upset conditions. Once a record of consistent performance has been established, Toxic solid wastes should be treated to destroy sampling for the parameters listed in this docu- toxic organics to levels below 0.05 milligrams per ment should be as described below: kilograms (mg/kg). Wastes containing toxic met- • Continuously monitor air emissions exiting the als should be stabilized to achieve levels in the air pollution control system where toxic organ- leachate below those indicated in Table 1. ics are being emitted at rates greater than 0.1 kilogram/hour. Ambient Noise • Analyze liquid effluents generated from the process at least monthly, and analyze solid Noise abatement measures should achieve either waste before sending it for disposal. the levels given below or a maximum increase in background levels of 3 decibels (measured on the Monitoring data should be analyzed and re- A scale) [dB(A)]. Measurements are to be taken viewed at regular intervals and compared with 394 PROJECT GUIDELINES: INDUSTRY SECTOR GUIDELINES the operating standards so that any necessary • Minimize air emissions and generation of toxic corrective actions can be taken. Records of moni- wastes, especially organics. toring results should be kept in an acceptable • Incinerate all toxic organic wastes except those format. The results should be reported to the containing toxic volatile metals. responsible authorities and relevant parties, as • Collect solvent vapors, including toluene. Re- required. cover solvents or incinerate them in a combus- tion unit. Key Issues • Manage as hazardous waste spent photo- graphic chemicals, plate developer, dye resi- The key production and control practices that will dues, and other wastes containing toxic lead to compliance with emissions guidelines can organics or metals. be summarized as follows: Sources • Put in place and use good management prac- tices, especially cleanliness and materials Swedish Environmental Protection Agency. 1991. “The control. Graphic Industry, Industry Fact Sheet.“ SNV 91-620- • Collect spent fixing solution. Reuse it, or man- 9305-3/91-03/500ex. Solna. age it as hazardous waste. USEPA (United States Environmental Protection • Recirculate liquid effluents. Agency). 1995. “Printing and Publishing: Sector • Do not use halogenated solvents. Notebook, EPA Envirosense Bulletin Board.” EPA/ • Use organic, solvent-free dyes and glues, 310-R-95-014. Office of Compliance, Washington, where feasible. D.C.