Journal of Cleaner Production 10 (2002) 225–235 www.cleanerproduction.net A uniform definition and quantitative basis for industrial ecology T.P. Seager * , T.L. Theis Center for Environmental Management, Environmental Manufacturing Management Program, Clarkson University, P.O. Box 5715, 104 Rowley Laboratories, Potsdam, NY 13699, USA Received 9 January 2001; accepted 15 August 2001 Abstract Industrial ecology (IE) has been characterized by a fragmented approach encompassing a number of different perspectives and analytical techniques. A uniform framework has yet to be established or proposed. This paper partially addresses this shortcoming by tracing some of the historical and intellectual antecedents of the field, providing a clear and concise lexicon of the biological analogue, and contrasting the two most promising analytical methods by which IE research may be carried out: life cycle assessment (LCA) and systems analysis. Although a number of comparative environmental metrics may be employed in cost-minimization or thermodynamic efficiency studies, no single measure is sufficiently developed to prioritize among qualitatively disparate types of environmental impacts. It is argued herein that the concept of chemical exergy of mixing may be the most promising basis for the development of a uniform, broad-based measure of chemical pollution, and that such a measure could significantly advance a scientific approach to IE. Some theoretical background is presented, although the reasoning herein is intended to be accessible to an interdisciplinary audience.  2002 Elsevier Science Ltd. All rights reserved. Keywords: Industrial ecology; Exergy; Environmental metrics 1. Intellectual and historical antecedents As an emerging science, industrial ecology (IE) has been accessible to researchers from a number of different disciplines [1], however, it has yet to establish a consist- ent definition or a uniform analytical framework — in part explaining why the concept of a natural analogue for study of industrial systems is far from universally embraced among environmental engineers, scientists or managers. IE has been variously described as a “para- digm shift” [2], a “broad umbrella of concepts, rather than a unified theoretical construct” [3] and an “aggre- gation of trends (that) is still being defined by its pro- ponents” [4]. A broad review of the historical origins of the term shows that a myriad of definitions, descriptions and new terms have appeared, disappeared or reappeared in the literature — only to confuse experts and neophytes alike. A new terminology or vocabulary must eventually * Corresponding author. Tel.: +1-315-268-3856; fax: +1-315-268- 4291. E-mail addresses: seagertp@clarkson.edu (T.P. Seager), theist@- clarkson.edu (T.L. Theis). 0959-6526/02/$ - see front matter  2002 Elsevier Science Ltd. All rights reserved. PII:S0959-6526(01)00040-3 be established that reflects the evolution of scientific thought [5]. A comprehensive literature review shows that there has been considerable uncertainty as to what IE is or should be. In the seminal paper which popularized the neologism, Frosch and Gallapoulos [6] proposed that industrial systems would function more efficiently and with fewer environmental impacts if they were modeled after natural ecosystems wherein “the consumption of energy and materials is optimized, waste generation min- imized, and the effluents of one process… serve as the raw materials for another process”. 1 This supposition is an extension of what Ayres [7] called industrial metab- olism and characterized as “the energy-and-value-yield- 1 The paper mentions two additional terms that become important to future discussions. ‘Dematerialization’ is defined as “the use of plas- tics, composites, and high-strength alloys to reduce the mass of pro- ducts”, and cited as an important trend in the auto industry wherein cars are becoming lighter, more fuel efficient, but also increasingly difficult to recycle as the materials from which they are manufactured become more diverse and complicated. Additionally, the paper refers to the “life cycle” of various industrial materials (e.g. metals and plastics), in which the origin, use and eventual fate of the materials are studied together to identify opportunities for resource savings.