Regulatory and customer-driven initiatives are increasingly focused on characterizing the environmental impacts of materials’ production (e.g., Product Environmental Footprint), as well as their life cycle burdens and benefits (e.g., Circular Economy). To this end, the chemical industry is being asked to provide ever greater and more sophisticated information to authorities and to customers and downstream users on the environmental footprints of the materials it produces and markets.

Metals, indispensable components of modern societies—underpinning economies, cities and transportation, communication, food and power networks—have complex life cycles that can span from months to centuries. The first life of a metal typically encompasses extraction, processing, manufacturing and fabrication, use, waste management, and recycling. Consecutive lives typically encompass the same stages, with the exception of extraction. Each step along a metal’s life cycle has the potential to present environmental challenges that must be quantified and weighed against societal values but also potential benefits to societies, economies, and biomes that require maximizing.

The metals and mining industry routinely conducts life cycle assessment studies, using the latest industry data, to monitor, document, and help to reduce the potential environmental impacts of their products and their processes. In addition, through the emergence of resource efficiency/circular economy as a driver within materials management, the metals and mining industry has utilized life cycle studies to generate information to inform users across value chains.

Historically, such studies have been conducted independently, potentially leading to inconsistent application of methods. In 2012, to facilitate alignment, representatives of the following organizations set out to review existing methods and propose uniform recommendations for key methodology decisions (PE International 2014):

  • The Aluminum Association

  • Cobalt Development Institute

  • Eurometaux

  • Euromines

  • International Aluminum Institute

  • International Copper Association

  • International Council on Mining and Metals

  • International Lead Association

  • International Lead Management Center

  • International Lead Zinc Research Organization

  • International Manganese Institute

  • International Molybdenum Association

  • International Stainless Steel Forum

  • International Zinc Association

  • Nickel Institute

  • World Steel Association

The results of this harmonization effort are reviewed in Santero and Hendry (2016). This exercise highlighted several areas of alignment in existing methodologies, as well as areas which were either less aligned or could benefit from harmonization. Recommendations for improved consistency for decisions regarding system boundaries, recycling allocation, co-product allocation, and impact assessment categories were then developed through a series of discussions among the participating organizations throughout 2012 and 2013. Efforts were taken in the creation of the document to ensure alignment with relevant international standards (ISO 14040 2006a, ISO 14044 2006b).

This Special Issue brings together a range of papers from the metals and mining industry exploring such alignment from the perspective of specific metals. The papers are therefore necessarily varied in the issues they address (reflecting a diversity of products, environmental impacts, allocation issues, and systems) but are tied together by a commitment to a harmonized approach to LCA for metals; high quality data and analysis; alignment with international standards and a full lifecycle approach to decision making and the assessment of environmental impacts of products and processes.

In addition to the harmonization paper of Santero and Hendry (2016), this Special Issue comprises results of product LCAs: lead batteries and architectural sheeting (Davidson et al. 2016), nickel-containing stainless steel rebar (Mistry et al. 2016a) and molybdenum-bearing advanced high-strength steels in the lightweighting of vehicles (Hardwick and Outteridge 2015); cradle to gate LCIs and impact assessments for manganese (Westfall et al. 2016), primary aluminum (Nunez and Jones 2015), nickel (Mistry et al. 2016b), and zinc (Van Genderen et al. 2016); and explorations of specific indicators and issues: a perspective on LCA harmonization from the International Molybdenum Association (Greig and Carey 2015), an application of novel approaches to water scarcity footprint calculation for primary aluminum (Buxmann et al. 2016), steel recyclability (Broadbent 2016) and the influence of durability and recycling on impacts of window frames (Carlisle and Friedlander 2016).

While these published papers represent some of the most recent efforts of the sector to collect, analyze, characterize, communicate, and critique industry data, there is ongoing work to update lifecycle databases, inventories, impacts, and indicators with representative and timely data and to continue methodological harmonization efforts. It is hoped that this Special Issue is the first in a series to communicate publicly the state of the art of the theory, method, practice, and application of life cycle assessment in the metals sector.