Life Cycle Assessment of Office Furniture Products

CSS Publication Number: 
CSS05-08
Author(s): 
Abstract: 

An increasingly important concern for indoor work environments is the environmental quality of the office space. Building- and insulation materials have often polluted the indoor air by off-gasing harmful substances, such as asbestos, formaldehyde, and others. Recently, environmental concerns have also extended to painting-, flooring/carpeting-, and furnishing materials, leading to related environmental regulation and certification schemes. 

Office furniture companies complied with these environmental standards through the development and marketing of less harmful products. As an instrument to gain competitive advantage, the office furniture industry has adopted environmental product performance beyond mere environmental compliance. As a result, today's environmental performance not only refers to the final product but the entire value chain along which a product is developed, manufactured, delivered, used, and retired.

This study focused on the life cycle assessment of environmental impacts related to three different pieces of Steelcase office furniture, which represented the three most common types of office furniture used (lateral file-, work surface-, and panel products). Life cycle assessment was conducted across five environmental impact categories, which were 'energy resource consumption', 'global warming potential', 'acidification potential', 'criteria pollutants', and 'solid waste'. Supporting data was collected and analyzed from almost 50 suppliers, two Steelcase operations, five waste management facilities, and various established databases. In all, the study reflected nearly 250 Steelcase manufacturing steps, 75 primary and secondary materials, and 250 tonkilometers in transportation.

Environmental impacts for all three office furniture product systems were retrieved from life cycle modeling in SimaPro. Overall, the energy resources consumed were 1520 MJ for the work surface, 2410 MJ for the lateral file, and 3730 MJ for the panel. Global warming potentials were 91 kg CO2 eqv. for the work surface, 219 kg CO2 eqv. for the lateral file, and 230 kg CO2 eqv. for the panel.  Acidification potentials ranged from 42 H+ mol eqv. for the lateral file, to 44 H+ mol eqv. for the work surface, and 82 H+ mol eqv. for the panel. Criteria pollutants were 0.0145 DALYs for the work surface, 0.0159 DALYs for the lateral file, and 0.024 DALYs for the panel. Solid waste accrued at quantities of 60 kg for the work surface, 67 kg for the panel, and 69 kg for the lateral file. Fig. E-1 depicts environmental impacts for the product systems evaluated.

Five significant effects were uncovered. First, most environmental impacts were caused by material production.  This was due to product system material intensities and low recycled contents. Impacts related to plastic- and aluminum production were disproportionately high. Second, 97%-99% of environmental impacts related directly to Steelcase operations came from electricity consumption for powder coating, machinery, welding, and compressed air. Third, material recovery at product end-of-life was low and led to considerable amounts of solid waste. Fourth, manufacturing waste was signifi cant, in some cases, particularly due to powder coating overspray.  Fifth, steel performed relatively well in terms of environmental impacts if used resourcefully. 

Smaller, however noteworthy effects were criteria pollutants released from diesel trailers/-trucks and dissimilar Steelcase ventilation needs depending on manufacturing location climate conditions.

For the lateral file product system, steel was the major contributor to total environmental impacts, simply due to the fact that steel constituted 97% of the product system total weight (Table E-1). PET production for thin-film powder accounted for up to 13.4% (criteria pollutants) in impact category totals despite its absolute mass contribution to the product system total of only 2%. For solid waste, production of 4 grams of copper - mainly related to welding tips - caused 1.1% of product system total solid waste. Less than 2% of environmental impacts for any given impact category were caused by suppliers as the lateral file product system was predominantly produced in-house. Powder coating operations at Steelcase, as a major electricity consumer, caused up to 15.4% (acidification potential) in product system impact totals.

For the panel product system, aluminum (25% recycled content) and steel were the major contributors to total environmental impacts, ranging from 8.4% to 27.5% (depending on impact category) for steel and 13.2% to 35.6% (depending on impact category) for aluminum (Table E-2). Cardboard (for packaging) and plastic production (excluding PET) accounted for up to 7.1% (acidifi cation potential) and 7.3% (energy resource consumption) in total environmental impacts respectively.  Production of 17 grams of copper for electrical receptacles generated 4.2% of panel product system total solid waste. Between 1.7% and 17% (depending on impact category) in total environmental burdens for the panel product system were related to suppliers (aluminum casting and electroplating zinc). Manufacturing activities at Steelcase contributed up to 3.1% (depending on impact category) to the panel product system total impacts (almost exclusively due to electricity usage).

For the work surface product system, the majority of contributions to total environmental impacts came from aluminum-, laminate-, steel-, and particleboard production (Table E-3). Supplier manufacturing accounted for up to 6.5% in total impacts (depending on impact category) for aluminum casting. Impact contributions related to Steelcase activities ranged between 1.1% and 4.3% (depending on impact category) of product system total impacts.

Product end-of-life for all product systems accounted for considerable impacts only with respect to solid waste.  On average, recycling rates for the U.S. municipal waste management system were low (29%) leading to incineration (15%) and landfilling (56%) of the larger fraction of each discarded product system.

Overall, this study was intended to provide internal Steelcase stakeholders working in design, engineering, sourcing, manufacturing, and marketing with knowledge that could be applied towards design improvements of Steelcase office furniture product systems. By including the results with other criteria, more informed decisions can be made regarding product development, manufacturing, and life cycle product stewardship.

Keyword: 
Furniture
Publication Type: 
Master's Thesis
Full Citation: 
Dietz, Bernhard. 2005. Life Cycle Assessment of Office Furniture Products. Master's Thesis, University of Michigan: Ann Arbor: 1-103.
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Publication Status: 
Published