Adhikari and Ozarska Environ Syst Res (2018) 7:6 https://doi.org/10.1186/s40068-018-0109-x REVIEW Open Access Minimizing environmental impacts of timber products through the production process “From Sawmill to Final Products” Shankar Adhikari1* and Barbara Ozarska2 Abstract As awareness of climate and environment issues increases and consumption habits change, new opportunities are opening up for the forest industry and wood construction to develop functional green solutions to meet consumers’ needs. Wood is a versatile raw material and the only renewable construction material. The manufacture of wood prod- ucts and structures consumes little energy in comparison to similar products and structures made of other materials. Unlike other materials, most of the energy needed to manufacture wood products is derived from renewable energy sources. The global timber sector currently faces the dual challenges of meeting the growing demand of quality timber products and minimising possible adverse impacts on the environment and human health. Major sources of environmental impacts occur throughout the wood supply chain from sawmills to fnal products. The major objective of this paper is to explore ways to reduce the environmental impacts of timber products, from sawmills to fnal prod- ucts. The specifc objectives include the identifcation of major sources and mechanisms of environmental impacts from timber products, the assessment of the status of energy consumption and GHG emission in wood products dur- ing timber processing and manufacturing as well as identifying the potential ways to minimize these environmental impacts. Keywords: Assessment, Environmental impacts, Minimize, Sawmill, Timber products Background demand is set to quadruple by 2050 (FIM 2017). As a Amidst growing environmental consciousness and result, there is growing concern about fulflling the need increasing demand for timber products, the importance for increasing demand for timber products without dete- of fulflling growing demand for these products on the riorating the world’s forest resources. Hence, enhanced one hand, and at the same minimizing environmental insight is required into ways of improving the efciency impacts, is increasingly recognized. While FAO (2001) of timber production process, reducing wood wastage had predicted that by the end of 2020, global consump- and helping the timber sector to address growing envi- tion of industrial timber products will increase by 45%, ronmental challenges (Eshun et al. 2012). UK based sustainable real estate organization FIM, based Timber products are regarded as products produced on existing growth levels, has forecasted that global tim- from renewable and sustainable environmental resources ber consumption in 2020 will be 2.3 billion cubic meters. (Klein et al. 2016). However, as other products, timber Tis is an increase of 24% from the 2015 level and equiva- products may create various kinds of environmental lent to a 4.4% increase per annum (FIM 2017). Moreover, impacts at diferent stages of the timber product supply Te World Bank has also forecasted that global timber chain, from harvesting to their disposal (Fig. 1). A major source of the environmental impacts is the consumption of energy required to produce timber products and emis- *Correspondence: [email protected] sion of greenhouse gases (GHG) during the manufac- 1 Department of Forests, Ministry of Forests and Environment, Kathmandu, Nepal turing process from raw materials to the fnal products. Full list of author information is available at the end of the article Although production of timber products also involves © The Author(s) 2018. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Adhikari and Ozarska Environ Syst Res (2018) 7:6 Page 2 of 15 Timber Products Producon Systems and Associated Wood Wastage Forestry SubsystemTimber Industry Subsystem Harvesng (Tree branches, sawdust, juvenile trees off-cuts) Log yard and Sorng (Sawdust, off-cuts) Skidding (Juvenile trees) Bucking & debarking (Barks, off-cuts & sawdust) Processing and Loading (wood off-cuts, sawdust) Transportaon Head rig sawing Block condioning (Slabs & sawdust) Edging Peeling & Clipping Slicing (Sawdust, slabs, off-cuts) (Peeler core & saw (Peeler core & sawdust) Cross cung (Sawdust, off- Veneer drying Resin preparaon & Veneer applicaon Air-drying Kiln Drying Hot pressing Circular sawing Sawing & trimming Resin preparaon & (sawdust & off applicaon ) Jointer and moulder Sanding (sawdust) Planer & sander Air-dried lumber Furniture Kiln dried lumber Plywood Veneer parts Fig. 1 Flow chart of activities in timber production stages and production of wastage in timber production sector. It represents the typical timber product production system, from harvesting to the fnal products through two subsystems viz the forestry and timber industry subsystems, within the timber production sector. Modifed from Eshun et al. (2012) Adhikari and Ozarska Environ Syst Res (2018) 7:6 Page 3 of 15 emission of carbon, forest and timber provide carbon human toxicity, eutrophication, and photo-oxidant for- sinks because trees consume carbon dioxide from the mation in Malaysia. atmosphere through carbon sequestration (Le Quéré et al. 2009). However, the forestry sector in general, and Manufacturing processes removal of trees through deforestation contribute to up Timber processing and manufacturing involves diferent to 17% of GHG emission into the atmosphere (Miles and types of machines and processes such as sawing, dry- Kapos 2008; Baccini et al. 2012). Other forms of environ- ing, machining, jointing, gluing and fnishing and so on, mental impact associated with timber products are due which can be connected to both environmental hazards, to the transportation of timber products (Lindholm and and workers occupational health and safety. Berg 2005), use of chemicals, and wood wastage (Jur- Te major hazards with the machines could be clas- gensen et al. 1997; Wootton 2012). sifed into mechanical (e.g. crushing, cutting, trapping, Figure 1 represents the typical timber product pro- shearing, abrasion, friction), structural (e.g. sharp edges, duction system, from harvesting to the fnal products. It projections, obstructions, potential to fragment, collapse, shows two subsystems, the forestry and timber industry, overturn), physical (e.g. electricity, pressurized content, within the timber production sector. noise and vibration, heat, moisture or cold temperatures), Te major objective of this paper is to explore ways to chemical (e.g. gases, fumes, liquids, dusts, that can cause reduce the environmental impacts of timber products, adverse health efects), ergonomic hazards (awkward from sawmills to fnal products. Te specifc objectives working positions, manual handling, repetitive move- include the identifcation of major sources and mecha- ments), and biological (e.g. present of bacteria, molds in nisms of environmental impacts from timber products, materials used or processed in machinery) (Bluf 2014; the assessment of the current status of energy consump- Poisson and Chinniah 2016). Furthermore, as workers tion and GHG emission in wood products during timber have to use machinery in all phases of its lifecycle from processing as well as identifying the potential ways to installation, through operation, maintenance, trouble- minimize these environmental impacts during the timber shooting, repairs, adjustments, set-up, production dis- production process. ruptions, to cleaning and dismantling, they get exposed Main sources of environmental impacts of timber to various hazards (Poisson and Chinniah 2016; Rus et al. products can be categorised into physical impacts of 2008). A study based on sixty-six Australian manufactur- timber processing, energy use and production of GHG ing frms which produce and supply machinery into local emissions. and international markets found that less than one in ten frms comprehensively recognized hazards, used safe Sources attached to physical impacts of timber place controls as the primary risk control measures, and products provided substantial, good quality information to mini- Te production process for timber products, from log mize environmental hazards, but the remaining frms did extraction to fnal products involves several stages, which not consider the environmental impacts (Bluf 2014). can afect the surrounding environments in the form of land, air and water pollution. Tis paper looks into the Wood waste and by‐products impacts of timber products from sawmilling to disposal. Preventing wood waste to improve the efciency of pri- mary wood utilization signifcantly helps to reduce the Sawmilling environmental impacts on the one hand, and fulfll tim- Te sawmilling process involves debarking and cutting ber product demands without further damage to world of logs into sections, which are sawn into timber boards. forest resources on the other. Dionco-Adetayo (2001) has Particulate environmental matter arises from log debark- found that out of 1 m3 of tree cut and removed from the ing, sawing into boards, wood residues and kiln drying forest, about 50% goes to waste in the form of damaged as these processing stages create environmental haz-