7. Have appropriate environmental controls been applied?

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Chapter 7: Have appropriate environmental controls been applied?

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Environmental Management Systems

Factors to consider

Different types of pollution can occur in many different places along the supply chain for wood and paper-based products (Figures 9 and 10). The amount and intensity of emissions depend on the type, condition and capacity of the equipment causing pollution and the location of the discharge points. The degree of deviation (i.e., lack of compliance) from legally established emission thresholds is also an important factor and the opportunity for continuous improvement exists.

Types of pollution include:

  • Emissions to air
  • Energy-related emissions resulting from the combustion of wood and fossil fuels to generate power
  • Processing emissions resulting from processes such as pulping, bleaching, pressing, evaporating, and the chemical recovery systems.
  • Solid emissions
  • Sludge from wastewater treatment plants
  • Ash from boilers
  • Miscellaneous solid waste, including wood, bark, non-recyclable paper, and rejects from recycling processes.
  • Emissions to water – large amounts of water are needed to carry the fibers through each manufacturing step in making paper products.
  • Noise – a concern in the immediate vicinity of a mill. Its impact depends on the proximity of human settlements and the mitigation measures taken.

More information on pollutants commonly associated with manufacturing of wood and paper-based products can be found in Box 8.

Bleaching can be a potentially major source of pollution (Box 9). Most of the global paper industry has phased out the use of Elemental Chlorine (EC) as a bleaching agent; however, some facilities still use it. The prevailing bleaching systems are Elemental Chlorine Free (ECF) and Enhanced Elemental Chlorine Free (EECF). Totally Chlorine Free (TCF) bleaching may be an option for certain products although it tends to use more fiber and produce a lower quality product.

The law is the formal reference for what constitutes an acceptable level of emissions in a country. No international agreement on acceptable levels of emissions exists, but some multilateral and bilateral lending institutions have established policies based on Environmental Impact Assessments (EIA).

Factors to consider regarding pollution

  • Engaging in dialogue with landowners, trade associations and NGOs can be useful as they are often familiar with specific issues and local circumstances.

  • The emission of pollutants is often specific to the country and the site. Some countries are more stringent in their regulation of emissions. Continuous improvement should be the goal; although compliance may not always be enough (e.g., in cases where requirements are not stringent) therefore holistic environmental impact reductions are also a goal. Adherence to the relevant and local regulations and/or international lending standards can be used as a proxy to assess a company’s procurement policy requirements.
  • Best management practices in the forest industry to deal with pollution include:
  • Minimizing the generation of effluents, air emissions and solid waste through better technology
  • Increasing reuse and recycling of waste materials
  • Increasing rates of chemical recovery from pulping and bleaching processes
  • Use of high-efficiency washing and bleaching equipment
  • Elimination of uncontrolled discharges of wastewater and solid waste due to equipment lack or failure, human error, or maintenance procedures
  • Usage of ECF, TCF, and EECF bleaching systems
  • Time-bound plans and management systems to minimize impacts from specific toxic pollutants.

Box 8. Pollutants

Pollutants of interest include:

  • Volatile Organic Compounds (VOCs): include a variety of organic chemicals including paints, lacquers, glues and adhesives, by-products of the processing wood, and others. VOCs are precursors of ground-level ozone.
  • Nitrogen Oxides (NOx): NOx are also precursors of ground level ozone.
  • Formaldehyde: in the atmosphere formaldehyde is rapidly broken down in atmospheric ions; formaldehyde is a component of acid rain.
  • Methanol: methanol reacts in the air to produce formaldehyde and other chemicals that are washed out by rain. Methanol is the most common VOC found in the production of wood and paper-based products.
  • Sulfur Compounds: in the atmosphere sulfuric acid contributes to acid rain, and it can be transported large distances from the point of release.
  • Volume and Quality of the waste water including:
    • Biochemical or Chemical Oxygen Demand (BOD) in the water discharge; BOD is the amount of oxygen that micro-organisms consume to degrade the organic material in the water. High levels of BOD can result in the reduction of dissolved oxygen in the water. This may adversely affect aquatic organisms. BOD is usually measured in kilograms per metric ton of pulp.
    • Chemical Oxygen Demand (COD) in the water discharge; COD is the amount of oxidizable organic matter and it can be used as an indicator of the quantity of organic matter in the water. COD is measured in kilograms per metric ton of pulp.
    • Total Suspended Solids (TSS); measured in kilograms per metric ton.
    • Absorbable Organic Halogens (AOX), including chlorine; there has been heavy pressure to stop using elemental chlorine in the bleaching processes because chlorine compounds can react with organics and generate chlorinated compounds (dioxins). Dioxins are persistent substances that have been considered a probable human carcinogen. AOX can be used as an indirect indicator of the quantity of chlorinated organic compound in the effluent. Reductions in the amounts of AOX can be used as indicator of continued technological improvement. However, AOX from ECF-bleached pulp do not contain highly chlorinated compounds.

Box 9. Bleaching of wood pulp

Wood is a composite material made of cellulose fibers, bonded and made rigid by lignin. To make paper, mechanical and chemical processes are used to separate the cellulose fibers from lignin and other compounds. Wood pulp intended for white paper products undergoes an additional bleaching process to remove residual lignin.

Bleaching increases the performance and the brightness of the fibers, increasing their absorbency and turning them from brown to white. In addition, bleaching disintegrates contaminating particles, such as bark, and reduces the tendency of pulp to turn yellow (an important feature for archiving of information).

Elemental Chlorine (EC), combined with small amounts of chlorine dioxide, was the historical bleaching agent of the paper industry. However, EC has been determined to be the source of highly chlorinated organic compounds (dioxins), which are toxic to animal and human health, and are considered a probable human carcinogen. Almost all of the global paper industry has stopped using EC and turned to alternative processes, including:

  • Elemental Chlorine Free (ECF) – chlorine dioxide is substituted for EC in the bleaching process; some processes also use additional bleaching agents such as oxygen and hydrogen peroxide.
  • Enhanced Elemental Chlorine Free (EECF) – removes more lignin and other contaminants before bleaching process through oxygen-based chemicals or prolonged delignification processes.
  • Totally Chlorine Free (TCF) – uses oxygen-based chemicals such as ozone and hydrogen peroxide instead of chlorine-based compounds. TCF bleaching reduces the formation of pollutants but it can also use a greater amount of wood and energy per unit of product; TCF fibers may not entirely satisfy the performance needs of certain products.

Sources: Paper Task Force, 1995; Markets Initiative website.