- How can Life-Cycle Assessment contribute to Sustainability?
- What are the main steps in a Life-Cycle Assessment?
- What are the strengths and limits of Life-Cycle Assessment in a sustainability context?
- How is Life-Cycle Assessment used to support EPA decision-making?
- Where can I find more about Life-Cycle Assessment?
- Illustrative Approaches Applying Life-Cycle Assessment
Life-cycle assessment (LCA) is a systems-based approach to quantifying the human health and environmental impacts associated with a product's life from “cradle to grave.” A full LCA addresses all stages of the product life-cycle and should take into account alternative uses as well as associated waste streams, raw material extraction, material transport and processing, product manufacturing, distribution and use, repair and maintenance, and wastes or emissions associated with a product, process, or service as well as end-of-life disposal, reuse, or recycling. In some cases, LCA is applied with restricted boundaries, such as “cradle to [loading] gate.” Environmental footprint analysis is a type of bounded LCA.
LCA typically return two specific types of information:
- A comprehensive life-cycle inventory of relevant energy and material inputs and environmental releases throughout the system.
- Estimates of the resulting impacts for a wide range of impact categories including global climate change, natural resource depletion, ozone depletion, acidification, eutrophication, human health, and ecotoxicity. 
This information allows an analyst to consider multiple parts of a system and multiple environmental endpoints in developing effective policies.
LCA principles and data form a core element of many efforts to assess sustainability. The “system-level” risk and emissions data that are incorporated into LCA allow an analyst to consider multiple parts of a system and multiple environmental indicators in developing effective policy.[200, 202] While traditional LCA addresses only environmental and human health impacts, the analysis can be expanded to consider economic impacts either by incorporating results into a benefit-cost analysis or by incorporating economic data and dynamics into LCA itself.[200, 203] Similar to chemical alternative assessment, green chemistry, and green engineering, LCA practitioners typically do not question the purpose of the original product or technology. Consequently, the sustainability analysis would be improved if LCA was one of several analytic efforts.
There are four major steps of an LCA study, as described in the ISO 14040 standard: 
- Step 1—definition of the assessment goal and scope. The goals focus on the specific product or question the LCA is calibrated to examine, and scope includes definition of “system boundaries” for the analysis, such as whether an analysis considers end-of-life management for a product. Goal and scope in a sustainability context should be defined through stakeholder engagement and collaboration and identify which products and technologies are to be evaluated;
- Step 2—compile the life-cycle inventory; which is a detailed account of all inputs and emissions that occur at each stage of the life-cycle scenario being examined;
- Step 3—conduct the life-cycle impact assessment of the product/technology using the life-cycle inventory data and one or more assessment methods that translate emissions into one or more impact categories, such as global warming potential (based on GHG emissions), water quality impacts, human health impacts, or many others; and,
- Step 4—interpret, summarize, analyze and communicate the results. This discussion should transparently communicate the limitations and uncertainties associated with the LCA results, including uncertainties associated with data (parameter) limitations, and with analytical (scenario and scope) assumptions.
LCA is a mature tool with a well-established set of methods and data that enables a direct comparison of alternatives associated with the analyzed product or technology. The ISO provides detailed international standards for development and peer review of LCA data and methods. User-friendly LCA-based applications that quickly provide limited results have been developed. For example, environmental footprint analysis focuses on one or a limited number of metrics. Another streamlined LCA approach uses economic input-output (I/O) analysis to estimate the emissions and environmental impacts that can be attributed to each industrial sector based on how much that sector spends on various goods and services. Finally, hybrid LCA methods combine the process-based approach with I/O analysis, thereby partially overcoming the boundary constraints and data gaps of traditional LCA.
Despite being a mature tool with well-established data, including extensive data quality procedures, LCA is still subject to limitations that should be considered within the sustainability context. LCA usually models “average” systems, and may not capture the impacts of policies that cause indirect changes or significant (non-marginal) changes in the market. For example, a shift in energy supply may affect power plant operations, and a new technology may create new demand (or eliminate demand) for other technologies. Additionally, the temporal and spatial detail of an LCA study may not provide sufficient granularity for some of the impact categories being considered.
With respect to LCA data, gaps in the availability of inventory data represent a barrier to LCA practice; data have not yet been assembled for some products, systems, and emissions (e.g., water use data can be limited even for well-understood systems). Filling data gaps requires significant effort, causing typical LCA studies to require many months to complete; however some streamlined alternatives to full LCA are available, such as Cumulative Energy Demand (CED), which focuses solely on energy. CED is a screening impact indicator to provide information on potential product environmental impacts and estimation of energy resource depletion by capturing direct and indirect energy use/demand during the complete life-cycle. Data to quantify CED may be more readily available than the data needed to conduct a full LCA, as less information is required; emission estimates/factors and impact assessment factors are not required. However, CED does not address issues such as water, land use, or pollution that are key to a full sustainability assessment.
There is a strong history of EPA developing and using LCA to support decision-making. For example, EPA helped develop two LCA models related to materials management (BEES and MSW-DST) as well as several calculators that use LCA data and methods (WARM, Remediation). The following are selected examples of how EPA program offices and regions are using LCA to support both regulatory and voluntary programs:
- Under the Energy Independence and Security Act of 2007 (EISA), Congress mandated that EPA conduct a lifecycle analysis to determine whether or not renewable fuels produced under varying conditions meet the greenhouse gas thresholds for the different fuel types defined under EISA. These assessments are required to certify that the volumes produced by industry are consistent with the goals defined in EISA.
- Both LCA and a broader adherence to “life-cycle thinking” that considers different stages in production and use of materials are used in EPA’s DfE Program, which has conducted comprehensive LCAs on computer displays, lead-free solders, and wire and cable insulation and jacketing.
- ORD’s National Risk Management Research Laboratory supports research activities on LCA methods and application in green chemistry, nanotechnology, chemically safe product designs, and characterization of pollutants released from products and building materials.
- The Office of Solid Waste and Emergency Response, in conjunction with the Office of Chemical Safety and Pollution Prevention, the Office of Policy, and several EPA Regional offices and States, issued a report entitled, “Sustainable Materials Management: The Road Ahead,” which uses economic and life-cycle inventory data to develop a relative ranking of materials, products, and services consumed in the US, accounting for life-cycle environmental impacts, resource use, and waste.
- The Office of Water is currently comparing conventional, or grey, stormwater management infrastructure from a life-cycle perspective with green infrastructure, or low impact development systems, which are designed to use natural processes such as evapotranspiration, infiltration, and bioremediation (e.g., plants and soil biota to manage and treat runoff). Some initial analyses indicate that green infrastructure practices can reduce the use of hardscape materials such as concrete and asphalt, pipes, energy, and labor needed to manage the runoff over the long term. In addition, practices such as green roofs can increase the life span of roof membranes and also reduce overall building envelope cooling costs and energy inputs.
- ORD hosts the website “LCAccess,” to promote the use of LCA to make more informed decisions through a better understanding of the human health and environmental impacts of products, processes, and activities.
- ORD has also created a series of LCA training modules (search terms: LCA and EPA).
- DfE has completed several LCAs of specific products:
- computer displays
- lead-free solder (PDF) (472 pp, 16MB)
- wire and cable insulation and jacketing (PDF) (311 pp, 2.9MB)
- Life-Cycle Assessment of Lithium Ion Battery Technologies
Source: EPA Office of Chemical Safety and Pollution Prevention
Suite of sustainability tools: life-cycle assessment; eco-efficiency analysis; green chemistry; collaborative-problem solving
Use of lithium-ion batteries is growing in the US as the number of applications expands and as government programs encourage their use. Lithium-ion batteries are currently used in many products, including computers and cell phones. New technologies are under development that will allow for the use of lithium-ion batteries in electric cars. As electric vehicles become more prevalent in the United States, interest in developing these technologies grows. 
With battery production on the rise, EPA’s DfE collaborated with EPA’s ORD to create the Lithium-ion Batteries and Nanotechnology Partnership in June 2009. The partnership is researching ways to produce batteries more efficiently and with fewer environmental impacts. DfE and ORD are conducting a quantitative environmental life-cycle assessment (LCA) of lithium-ion batteries used in electric drive vehicles, as well as of the nanomaterials and nanotechnology used to produce them. Quantitative LCA is a technique for assessing potential environmental impacts associated with a product, process, or service. LCA helps battery manufacturers and suppliers to identify materials and processes that are associated with fewer environmental impacts and greater energy efficiency.
In this case, the quantitative LCA assesses energy systems and environmental impacts at all stages of the batteries’ life: raw materials extraction and acquisition, materials processing, product manufacture, product use, and final disposition and end-of-life. The project is also assessing a nanotechnology application that has the potential to reduce environmental impacts. For example, this study is assessing battery anodes made from single walled carbon nanotubes. These anodes show promise for increased current capacity, extended electric vehicle range and battery life, and reduced recharge cycle time.
To perform this analysis, DfE partnered with a number of battery manufacturing and recycling companies, research institutions, the Department of Energy’s Argonne National Laboratory, and non-governmental organizations.
- Enhancing Supply Chain Performance with Environmental Cost Information: Examples from Commonwealth Edison, Andersen Corporation, and Ashland Chemical
Source: EPA Office of Chemical Safety and Pollution Prevention
Suite of sustainability tools: green accounting; life-cycle analysis; benefit-cost analysis
Corporate decision-makers typically do not have costs and benefits available relating to their corporate environmental, health, and safety (EH&S) performance. Such costs may include not only those costs historically associated with EH&S, but also costs associated with material usage, labor, and capital resources. Heightened recognition of these costs through environmental managerial green accounting approaches often reveals cost-effective opportunities to prevent pollution and eliminate wastes, and encourages business decisions that are both financially superior and beneficial to the environment.
Supply chain management is a particularly promising area for the application of green accounting techniques. Many firms already pursue strategies that emphasize eco-efficiency, i.e., improving material utilization per unit of production. By expanding those efforts to include purchasing, inventory management, materials handling, disposition and logistics, companies can further improve environmental and cost performance. Environmental managerial green accounting methods enable them to identify and quantify the most viable opportunities.
This collection of case studies (PDF) (55 pp, 252K) from EPA’s Office of Chemical Safety and Pollution Prevention illustrate how supply chain management practices can be improved by determining the financial impact of business activities that have a bearing on a company’s environmental performance. Moreover, this report shows how environmental managerial green accounting approaches can be integrated into ongoing business processes. The report includes case studies of multi-disciplinary processes at three companies: Commonwealth Edison, Andersen Corporation, and Ashland Chemical Company. While the approaches vary among these companies, each one provides valuable lessons for other companies.
The experience of Commonwealth Edison (ComEd), a large Chicago-based electric utility company with annual revenues of approximately $7 billion, demonstrates that electric utilities and other companies can successfully and substantially reduce their costs and environmental burdens with innovative accounting practices. In 1993, ComEd began to recognize that the total cost of managing materials and equipment was much more than the initial acquisition cost. In particular, company managers realized that the costs related to environmental management were often overlooked. This acknowledgment led to ComEd’s first phase of life-cycle management activities, which enabled them to minimize the chemical inventories at generating stations. These reductions and other early successes prompted ComEd to launch a formal Life-cycle Management (LCM) initiative in 1995. Since then a small, dedicated LCM staff has formed effective partnerships with ComEd operating divisions to systematically assess life-cycle costs and benefits.
ComEd’s LCM initiative has reduced waste volume while providing over $50 million in financial benefits. While these gains include improvements in supply chain management, facility management, and other business processes, this case study focuses on the supply chain activities.
The activities of Andersen Corporation illustrate how a company can improve its financial and environmental performance by using environmental managerial green accounting information in supply chain management decisions. As the largest manufacturer of wood windows and patio doors in North America with annual revenues of approximately $1 billion, this company achieved substantial financial and environmental benefits when it began incorporating environmental considerations into its purchasing, materials handling, inventory, and disposition decisions.
In the late 1980s, executives at Andersen released a directive to their staff to reduce emission levels of toxic chemicals. In response to the directive, Andersen managers formed a Corporate Pollution Prevention Team whose mission was to eliminate the use, release, and transfer of hazardous chemicals. This multi-disciplinary team conducted a waste accounting project, developed waste reduction goals, and justified waste reduction projects by developing several business cases that quantified environmental and other cost savings. For example, the team justified the purchase of an improved system for mixing paints at point-of-use based on the savings from improved material usage rates and reduced waste.
Based on their initial success, company managers recognized that a more systematic implementation of environmental accounting techniques would improve their ability to make strong business cases for a wide range of projects. Accordingly, they developed procedures for environmental cost assessments for a number of supply chain management activities. The process leads to more comprehensive and lucid business cases, including detailed Internal Rate of Return schedules that incorporate savings from increased material efficiency and reduced waste streams.
While a number of companies have adopted environmental accounting practices, relatively few have fully integrated these activities into their established cost accounting methods. The Electronic Chemicals Division of Ashland Specialty Chemical Company achieved this integration during a manufacturing cost analysis in 1999. The corporate auditing team and an external consultant led a process of identifying and quantifying a number of cost reduction opportunities. Several of these opportunities supported the company’s overall goal of using materials more efficiently and minimizing waste.
This case study describes how the company integrated its Manufacturing Cost Analysis and EH&S Cost Study and provides specific tools that can help companies realize similar objectives. These tools include a detailed list of environmental activities, a representative list of interviewees, and a time allocation worksheet for capturing hidden EH&S costs. The integration effort uncovered at least one sizeable cost reduction opportunity and has led the company to make EH&S cost considerations an established part of its broader cost audits.
- Green Report: District of Columbia
Source: ECOS Green Report: Case Studies on State Efforts to Achieve Sustainability, March 2012  [Used with permission from the Environmental Research Institute of the States (ERIS), the Environmental Council of the States (ECOS), and the District of Columbia]
Suite of sustainability tools: segmentation analysis; social network analysis; social impact assessment; environmental justice analysis; life-cycle assessment; futures methods; benefit-cost analysis; eco-efficiency analysis
The District Department of the Environment (DDOE) is currently coordinating a citywide sustainability planning effort for the Mayor. The Agency does not have an “official” formal definition of sustainability at this time. However, the Agency frequently uses a working definition that defines sustainability as the nexus of the environment, economics, and equity. DDOE also describes sustainability as meeting the needs of the present without compromising the ability of future generations to meet their own needs. These definitions are intended to be grounded in environmental protection, but inclusive of the critical connections between environment, economy, and equity.
DDOE is home to core state and local programs that are simultaneously addressing sustainable practices including water and air quality protection, wildlife preservation and restoration, land remediation and toxics reduction, energy efficiency, and conservation. The Agency is working to integrate traditional regulatory programs into citywide sustainable efforts to strengthen programs and achieve the greatest possible environmental, health, economic and other equity benefits of cross-media coordination.
DDOE is co-lead (with the DC Office of Planning) of the Mayor’s sustainability planning process called Sustainable DC.
Sustainable DC was launched in September 2011 with an intensive community outreach program. Throughout September and October, staff attended 50 community meetings and events to hear people's visions for a sustainable DC and actions the community can take to realize those visions. In November 2011, nine working groups (focusing on the built environment, climate, energy, food, nature, transportation, waste, water, and the overall green economy) were launched to develop recommended goals, actions, and indicators. These recommendations will be integrated into a draft plan in summer 2012.
In this role, DDOE is playing a coordination function among the Green Cabinet, representing more than a dozen key agencies directly affecting citywide sustainability, including transportation, public works, health, public schools, real estate, economic development, employment services, and water and housing authorities.
STAR Community Index
DDOE also is coordinating with a national effort to develop the STAR Community Index . This is a framework for gauging the “triple bottom line” of sustainability and livability of US communities. STAR is intended to transform the way local governments plan and develop policies in the way that the US Green Building Council’s LEED program transformed the building industry. STAR will measure a jurisdiction’s sustainability across measures in specific categories. Through these standardized measures, cities will be able to more objectively assess their progress towards sustainability and compare themselves to other cities across the country.
Because of the size and complexity of STAR’s scope, ten jurisdictions were selected to serve as beta communities (Atlanta, GA; Austin, TX; Boulder, CO; Chattanooga, TN; Cranberry Township, PA; Des Moines, IA; King County, WA; New York, NY; St. Louis, MO; and the District of Columbia). These communities will test and review the measures for appropriateness and feasibility.
Benefit-Cost Analysis and Eco-Efficiency Analysis
DDOE implements stormwater management projects on public sites. When evaluating project proposals, DDOE staff evaluates the cost/benefit of each proposal. The evaluation includes an analysis of the dollars per gallon of stormwater retained or treated, and whether the proposal will implement new technologies that may be beneficial to the District’s water quality efforts. At a much larger scale, staff is analyzing the relative environmental, economic development (jobs), and social equity benefits of digging huge tunnels to manage stormwater flows versus a large-scale deployment of green infrastructure (i.e., Low-Impact Development). Whereas traditional analysis might only look at the relative environmental performance and costs of these systems, this new sustainability-driven analysis will assess job creation, social support (i.e., unemployment and other social services) investment reduction, heat-island effect mitigation, community beautification, property value enhancement, and the costs and environmental performance of these systems.
Environmental Justice Analysis
DDOE considers social equity as a cornerstone of sustainability. Like many other states and local jurisdictions, DC, through DDOE’s Office of Enforcement and Environmental Justice, reviews major development plans to assure that no disparate environmental harms are imposed on minority and low-income populations. Under the Mayor’s evolving sustainability strategy, EJ will likely evolve into much more than a risk assessment/risk management process, and will become a means of assessing the relative benefits of District investments on the distribution of opportunity and hardship across the city. A good example is the new program incorporated into the DDOE’s proposed stormwater regulations, which would allow off-site stormwater mitigation for projects that cannot meet the city’s aggressive 1.2 inch rainfall retention standard. These off-site projects likely will occur in less-developed portions of the city, which tend to be DC’s lowest-income communities. This option will bring substantial investment in tree planting, bioretention, green roofs, and other practices that will not only allow more and better stormwater management, but also will create jobs and beautify neighborhoods– and reduce the significant social disparities across DC. And the program will increase stormwater management by over 50 percent, while reducing costs by 30 percent.
Future Scenario Analysis
During the next year, DDOE will forecast the impacts of the District’s revised stormwater regulations. The purpose of this analysis is to determine how future development will lead to improvements in water quality and how DDOE’s new off-site mitigation program will impact EJ issues in the city.
The District's revised stormwater regulations will include a payment-in-lieu option for sites that cannot otherwise meet their regulatory obligations. To determine the appropriate price for this option, DDOE staff developed a life-cycle cost assessment to capture the full cost of implementing stormwater practices.
Segmentation Analysis, Social Impact Assessment, and Social Network Analysis
The District has developed a new social marketing campaign to reduce litter. The campaign includes significant social and psychological (focus groups and interviews) analysis to determine the root causes of litter and to develop effective messages and approaches that will have an impact. Additionally, the program has surveyed residents to evaluate the impact of the marketing campaign as well as the new Bag Law that requires a 5-cent fee on disposable paper and plastic bags.
In addition to the tools mentioned above, DDOE has developed some new tools to measure the District’s sustainability activities:
- Green Dashboard
To help residents understand the District’s progress in becoming a more sustainable place in which to live, work, visit, and play, DDOE’s Office of Policy and Sustainability developed an online interactive Green Dashboard containing approximately 60 indicators in six categories (air quality and climate, energy and buildings, nature, transportation, waste and recycling, and water). Users are able to manipulate the data by time period and metric to suit their interests and will be able to also download raw data and image files of graphs for later use. Additionally, the Dashboard provides contextual information for each indicator, including information on what the data mean, why they are important, how the District compares to other jurisdictions, and ways users can get involved. Information is presented in an easy-to-read style with images and links to make the information engaging and digestible.
- GreenUp DC
DDOE developed GreenUp DC, an interactive web tool that teaches property owners how to reduce their energy footprint and stormwater releases. The tool tracks energy reduction and stormwater activities, and creates reports that allow DDOE to fulfill its legal obligations to US EPA. GreenUp DC allows DDOE to be transparent and responsive with up-to-the-minute statistical reporting on energy performance and stormwater reductions.
- Green Dashboard
- EPA Design for the Environment
Source: EPA Office of Chemical Safety and Pollution Prevention
Suite of sustainability tools: chemical alternative assessment; green chemistry; collaborative problem-solving; life-cycle assessment; risk assessment
EPA’s Design for the Environment (DfE) Partnership Program helps consumers, businesses, and institutional buyers identify products that perform well and are cost-effective, but are safer for human health and the environment. This program promotes sustainability by working with small businesses and consumers to identify risks involved with chemicals used in products or manufacturing processes. Chemical Alternatives Assessment is a key analytic tool for the implementation of DfE. It is a tool for evaluating chemicals of potential concern by comparing alternative chemicals within the same functional-use group across a consistent and comprehensive set of hazard endpoints. Other analytic tools that are instrumental for the conduct of this program include risk assessment and life-cycle assessment. Through the DfE, EPA collaborates with industry, environmental groups and universities to decrease health and environmental risk by encouraging green design and reformulation of a wide range of products while maintaining their effectiveness. As more consumers seek sustainable products that are designed to have minimal impact on the environment and their health, an environmental “seal of approval” could help consumers select products that match their values.
DfE offers that “seal of approval” by awarding use of the logo on products that meet environmental design criteria. The logo assures consumers that the DfE scientific review team has screened each ingredient for potential human health and environmental effects and that—based on currently available information, EPA predictive models, and expert judgment—the product contains only those ingredients that pose the least concern among chemicals in their class. Products are also expected to meet effectiveness criteria, i.e., glass cleaners must meet criteria for effective glass cleaning. To obtain the DfE recognition, ingredients in the formulation must be publically disclosed (with the exception of specific allowances for trade secret ingredients). EPA also offers the DfE label to partnering companies that design or reformulate high-performance and cost-effective products using the safest ingredients.
The screening process (PDF) (43 pp, 726K) for the DfE logo is detailed and comprehensive. DfE scrutinizes ingredients, starting with known toxicity information and performing an inherent property analysis when toxicity information is not available. With inherent property analysis, scientists estimate toxicity for a chemical ingredient without toxicity information using available toxicity information for a chemical with similar structure. Strong structural similarities to a chemical with high environmental or health toxicity would be a flag for concern.
DfE sets specific standards for chemicals of known toxicity. For example, DfE will not recognize products that contain any pollutants on the Hazardous Air Pollutants list. Furthermore, DfE will not recognize products that contain chemicals on the EPA Toxics Release Inventory chemical list unless they meet stringent DfE criteria.
This program fosters sustainability in a cost-effective way that benefits companies, consumers, and environmental and public health. Through such partnerships and education, EPA is helping businesses and consumers select safer chemicals and technologies, thereby reducing the number of potentially hazardous chemicals in use.