U.S. hardwood industry encourages decisive move towards Environmental Product Declarations (EPDs)
At Interzum Cologne in May 2011, AHEC held a press conference to communicate the importance of the LCA research being undertaken by PE International. A major international effort is now underway to ensure that Environmental Product Declarations (EPDs) become a key part of the material selection process in the building sector. Despite their growing significance, awareness of EPDs amongst most material suppliers is still relatively low.
The American Hardwood Export Council (AHEC) has begun to address this issue in the wood sector through a major project launched at the end of last year. The project aims to promote compilation and use of EPDs in line with international standards by European and Asian joinery and furniture manufacturers of hardwood-based products. The innovative project, which is being undertaken by PE International (PE), may offer lessons for other suppliers to the building sector. EPDs are third-party verified ecolabels that disclose the environmental performance of products in much the same way as a nutrition label discloses nutritional performance. EPDs can be prepared by industry associations for generic products (for example “American red oak lumber”) or by companies for specific product lines.
The development of EPDs is a response to the confusion that arises from the wide variety of environmental claims made by material suppliers, some of which may be genuine and others bogus. A huge array of labelling systems has evolved, many certifying only a small part of the material supply chain which in reality may have only a marginal impact on the overall environmental footprint of a product. The development of EPDs also responds to a criticism of those building rating systems like LEED which allocate environmental credits to construction materials in an uncoordinated way on the basis of single attributes. This approach produces seriously inconsistent results. For example, LEED credits “regional materials” (defined as those harvested and processed or extracted and processed within 500 miles of the project) despite LCA demonstrating that transport contributes only a relatively small proportion to the overall environmental footprint of most materials. Similarly, the LEED credit for "rapidly renewable" materials cannot be justified on environmental grounds, sending out completely the wrong signal with respect to competing land uses. It implies that it is environmentally appropriate to remove forests managed on a long rotation for timber in favour of short-rotation agricultural crops.
EPDs can overcome these problems by delivering information on the full environmental impact of a material or product across its entire life cycle. They help to ensure that efforts to reduce one impact do not result in environmental degradation elsewhere. International standards have been developed to ensure that the information provided in EPDs is comparable and that environmental assessments are performed in the same way and yield the same results no matter who does the analysis. Requirements for LCA are set out in the ISO 14040 series of standards including, for example, rules for stakeholder consultation and peer review to ensure credibility. Requirements for EPDs (or “type III environmental declarations”) are found in ISO 14025. Amongst other things, ISO14025 requires a program of Product Category Rules (PCRs) which are the detailed instructions on how to perform the LCA for EPDs in specific sectors. In 2007, basic requirements for product category rules for EPDs for building products were set out in ISO 21930.
Use of EPDs is expanding rapidly in Europe where they provide the foundation of all the leading green building rating systems including DGNB (Germany), BREEAM (UK and Netherlands) and HQE (France). Formal Europe-wide standards for preparation of EPDs and for their use in environmental assessment of whole buildings are currently being prepared by CEN, the European standards institute. The EU is also developing a proposal that would require mandatory provision of basic EPDs for all products requiring CE Marking. Starting this year, France is already phasing in a mandatory requirement for EPDs for all consumer goods.
Sustainable wood supply
An important starting point for preparation of EPDs in the wood sector is to assess the sustainability of harvesting at source. Forests act as carbon sinks, since trees absorb carbon dioxide from the atmosphere through photosynthesis and store it as carbon. When the trees are harvested, much of the carbon remains stored in all the ensuing products thus mitigating climate change. Under the terms of EPD programs and carbon footprint standards (like the UK’s PAS 2050 standard), wood products may only be credited with this carbon storage effect if they derive from a renewable source where growth exceeds harvest.
For this reason, the AHEC project incorporates a detailed analysis of U.S. government forest inventory data gathered at regular intervals over the last 60 years. This demonstrates that the volume of hardwood standing in U.S. forests increased by more than 100% from 5.2 billion m3 to 11.4 billion m3 between 1952 and 2007. Due to very low levels of hardwood forest utilisation, projections of U.S. hardwood supply indicate that harvests could rise from current levels of less than 100 million m3 to in excess of 250 million m3 within the next 40 years without threatening long term sustainability. Analysis of hardwood growth and removals indicates strong potential to significantly increase supply of most American hardwood species, with particularly strong potential in soft maple, tulipwood, red oak, white oak, ash, hickory, and hard maple.
Furthermore, due to declining domestic demand for U.S. hardwoods over the last decade, a much larger proportion of supply will be available to supply export markets. Current U.S. hardwood lumber exports of around 2.5 million m3 a year could, in theory, rise to over 15 million m3 without detriment to the forest resource - although in practice achieving such an increase is constrained by availability of hardwood logging and processing capacity in the U.S. and intense competition in export markets both from wood and non-wood products.
Life Cycle Inventory data for US hardwoods
PE is now compiling Life Cycle Inventory (LCI) data for kiln dried American hardwood lumber from point of extraction in the forest through to point of delivery to the importers yard. The work builds on a project of the U.S. Consortium for Research on Renewable Industrial Materials (CORRIM) which is creating a comprehensive and consistent LCI database covering forestry and logging practices, sawmilling and some aspects of kiln drying. CORRIM’s data on hardwood forestry operations in the U.S. is sufficiently comprehensive that PE has been able to concentrate their research effort on other processes. PE is refining the CORRIM data on hardwood kiln drying – which provides generic data for “hardwood lumber” - to take account of variations between hardwood species and thicknesses.
An on-line questionnaire has been issued to hardwood processors in the U.S. to collect more detailed data on the kiln drying component. The questionnaire also covers the energy mix (bio-energy versus fossil fuels) during kiln drying and details of transport distances and modes of transport of logs and lumber within the U.S. Companies covering a wide range of processing types and locations are being asked to complete the questionnaire to ensure data is broadly representative of the export industry as a whole. Information from the questionnaire will be used to produce industry average LCI data for different species and thicknesses of U.S. hardwood lumber and veneer at point of delivery in major European and Asian markets.
The data collection process, which currently covers U.S. hardwood lumber only, will soon be extended to include U.S. hardwood veneers. After the primary data collection for lumber and veneers is complete, this will be compiled and linked with other LCI data sets (e.g. region-specific power mixes, transportation and fuel production processes) using PE’s unique GaBi 4 LCA software. This will provide all the data necessary to compile generic EPDs for American hardwood lumber and veneers. The EPD data will then become an integral part of the AHEC Species Guides, extending the existing technical performance data to provide comprehensive coverage of environmental aspects. In the absence of existing PCRs for hardwood sawn lumber and veneer, AHEC will work with PE, other trade associations and manufacturers to develop these in line with relevant international standards (ISO 14025). AHEC will also be contacting European and Asian wood product manufacturers directly to identify companies using American hardwoods that would be willing to engage with AHEC to publish a range of product-specific EPDs.
In order to ensure credibility of the project it will be subject to independent peer review in line ISO requirements. An external review panel is currently being constituted which will be composed of at least 4 members including internationally recognized experts in LCA, relevant ISO standards, and the wood products sector, together with representatives from the environmental NGO community and at least one other material supplying sector with an interest in promoting development of EPDs.
Sensitivity analysis of environmental impact of different materials
Another innovative component of the project will measure the environmental implications of specifying American hardwoods in place of other wood and non-wood materials for several specific furniture and joinery products. Through AHEC’s contacts with manufacturers in Europe and Asia, a small number of specific products will be selected – for example a chair manufactured in Germany, a table manufactured in Italy, or a door manufactured in Spain – to undertake a detailed sensitivity analysis. An overall design, function and service life will be agreed for each product, and then the environmental impact of using different combinations of materials assessed. Account will be taken not only of the life cycle impacts of delivering the various materials to the manufacturer, but also of the implications of the different materials for service life and end-of-life handling.
This project component will not only inform material suppliers and manufacturers of the relative environmental impact of using American hardwoods compared to other materials, but also of where the environmental “hot spots” lie within the supply chain of these materials. In the end, this is the real strength of an LCA based approach to material specification applied through use of consistent and comparable EPDs. It allows much better targeting of measures to improve environmental performance. In some cases, it may be better to switch materials to improve the overall environmental profile of a product. In others, there may be better opportunities to improve performance through adjustments in the supply, processing, use, and disposal of the existing preferred material. An EPD programme provides the information necessary to make these judgements.