17 Life Cycle Assessment (LCA)

K.N. Yogalakshmi

1. Introduction

2. Brief History

3. Life Cycle Assessment

4. Types Of LCA

4.1 Cradle to grave

4.2 Cradle to gate

4.3 Cradle to cradle or closed loop production

4.4 Gate to gate

4.5 Well to wheel

4.6 Economic input output life cycle assessment

4.7 Ecologically based LCA

5.   Technical Framework Or Procedure

5.1 Goal and Scope

5.2 Life Cycle inventory analysis

5.3 Life Cycle Impact Assessment

5.4 Interpretation

6.   Advantages

7.      Disadvantages

1. Introduction

‘Save the EARTH’ is now hot in bowl being driven by the growing global concern over the increasing trend in overexploitation of non-renewable and finite material resources and degradation of the earth’s life support systems. With increasing environmental awareness, society has become much concerned about the issues of natural resource depletion and environmental degradation. Industries and business companies have also started to assess how their activities and product performance affect the environment. A number of businesses have responded to this awareness by providing “greener” products and using “greener” processes. Numerous companies have found it advantageous to explore ways of moving beyond compliance by use of pollution prevention strategies and environmental management systems for improving environmental performance. One such tool is called life cycle assessment (LCA). The LCA concept considers the entire life cycle of a product.

The Third Chapter of the World Summit on Sustainable Development (WSSD) Johannesburg Plan of Implementation (United Nations, 2002) included a call for, “…the development of a 10 year framework of programs in support of regional and national initiatives to accelerate the shift towards sustainable consumption and production patterns that will promote social and economic development within the carrying capacity of ecosystems…”. The use of life cycle approaches can contribute information towards the development of practical action plans and programs to address unsustainable consumption, degradation and production pattern.

2. Brief History

Life Cycle Assessment, or LCA, analyses the environmental impacts associated with products, or product systems. It has its origins in the early seventies; LCA type studies were performed in some countries, particularly in Sweden, the UK, Switzerland and the USA. In the 1970’s, the USEPA redefined the methodology for evaluation of environmental impacts of products and these were popularly known as resource and environmental profile analysis (REPA). The method had its roots in energy and waste management, and the products upon which analysis was executed in this initial period were beverage containers and diapers. In the early 1980s assessments of product life cycle experienced a second life through studies of the environmental loadings and the potential impacts of beverage containers (e.g., beer cans, milk bottles) performed in various European countries. These involved further elaborations of the principles governing the assessment of a product’s life cycle and involved a series of life cycle assessments of materials used in packaging containers like polyethylene, cardboard, aluminium, etc. But being performed using different methods and without a common theoretical framework, the consequences were largely negative. Even with the same product/process of study, there was often marked difference in the results obtained, which has hampered the development of LCA into a more widely accepted analytical tool. But there has been a growing exchange of knowledge and experience among LCA experts since around 1990. Under the efforts of the Society of Environmental Toxicology and Chemistry (SETAC) measures were undertaken to harmonize methodology. It produced its “Code of Practice” in 1992. This document marked a significant opening move in the further approaches to LCA. Then the International Organization for Standardization (ISO), on behalf of the standardization of environmental management, ISO 14000, prepared an LCA standard, ISO 14040 series, and a standard for LCA-based environmental product declarations. Since 1994, the ISO has played an important role and from the year 2000, UNEP also was actively involved in stimulating the application of life cycle approaches in practice. The list of products subjected to LCA since past years has grown rapidly and now includes more complex products such as paints, refrigerators, window edgings, hotplates, TV sets and other service systems or technologies.

3. Life Cycle Assessment

Life cycle of a product refers to the complete time span of its existence. It starts from its making which includes raw material extraction for manufacture, to the end of its use phase i.e. till its destruction. The life cycle consists of the technical system of processes and transport routes used, raw materials extraction, production, use and after use (which can be waste management or recycling). LCA is also called as “cradle-to-grave” assessment for this reason. LCA approaches are guided by standards, but a professional code of practice has also been developed (Consoli et al. 1993).

The entire production life cycle from cradle to grave should be assessed to identify the environmental impacts of a product or service. This notion is called ‘life cycle thinking’. Life cycle approaches are means for estimating the impacts of material and energy flows along the production chain. It involves calculation and evaluation of the environmentally relevant inputs, outputs and their potential impacts on the environment (SABS ISO, 1998). In geneeral, the environmental inputs and outputs refer to demand for natural resources, harmful emissions and solid waste generation.The results of these assessments can be used for internal and external purposes for process development and stakeholder communication, respectively. Ideally, they identify the main impacts and help in finding solutions to minimize environmental effects (Rebitzer et al. 2004). Briefly, ISO 14040 defines LCA as ‘a technique for assessing the environmental aspects and potential impacts associated with a product by compiling an inventory of relevant inputs and outputs of a system; evaluating the potential environmental impacts associated with those inputs and outputs; and interpreting the results of the inventory and impact phases in relation to the objectives of the study’.

4. Types Of Lca

4.1 Cradle-to-grave

Cradle-to-grave is the complete LCA starting from raw material extraction (‘cradle’) to use phase and disposal phase (‘grave’). All inputs and outputs are reflected for all the stages of the life cycle.

4.2 Cradle-to-gate

Cradle-to-gate is an assessment of partial life cycle of a product from raw material extraction (cradle) to the factory gate (before it is transporting to the consumer). The use phase and disposal phase of the product are omitted in this case.

4.3 Cradle-to-cradle or closed loop production

Cradle-to-cradle is a kind of cradle-to-grave assessment, where the end-of-life disposal step for the product is a recycling process. This method minimizes the environmental impact of products by employing sustainable production, operation, and disposal practices.

4.4 Gate-to-gate

Gate-to-gate is a partial LCA considering only one value-added process in the entire production chain. Gate-to-gate modules may also later be associated with their appropriate production chain to form a complete cradle-to-gate evaluation.

4.5 Well-to-wheel

Well-to-wheel is the LCA used for transport fuels and automobiles. The analysis is often fragmented down into stages entitled “well-to-station”, or “well-to-tank”, and “station-to-wheel” or “tank-to-wheel”, or “plug-to-wheel”. The first stage that involves feedstock or fuel production, processing and fuel delivery or energy transmission, is known as the “upstream” stage, while the stage dealing with vehicle operation is often called the “downstream” stage. Then, the well-to-wheel analysis is frequently used to evaluate total energy consumption, or the energy conversion efficiency and emission influence of marine vessels, aircraft and automobiles.

4.6 Economic input-output life cycle assessment

Economic input–output LCA (EIOLCA) involves the use of sector wise aggregated data on the quantum of environmental impact that can be imposed on the environment by each sector of the economy. Such analysis can account many connected business sectors.However, EIOLCA depends on sector-level averages which may or may not be characteristic of the specific subsection of the sector related to a particular product and therefore is not suitable for evaluating the environmental impacts of products. Also, the translation of economic quantities into environmental impacts is not validated.

4.7 Ecologically based LCA

A much wider range of ecological impacts is considered in case of an ecologically based LCA as compared to a conventional LCA. It is planned to provide a guide to the prudent management of human activities by understanding the direct and indirect impacts on surrounding ecosystems and resources. It was developed by Ohio State University Center for Resilience.

5. Technical Framework or Procedure

LCA consists of four components namely (i) Goal and scope; (ii) Inventory; (iii) Impact assessment; and (iv) Interpretation

For sucessful LCA analysis, ISO (2000), has laid the following standards as a part of ISO 14000 series: It includes

• ISO 14040: Environmental Management – LCA – Principles and Framework.
• ISO 14041: Environmental Management – LCA – Inventory Analysis.
• ISO 14042: Environmental Management – LCA – Impact Assessment
• ISO 14043: Environmental Management – LCA – Interpretation.

5.1 Goal And Scope

To ensure the constancy of the LCA study, the goal should state the aim of carrying out the study and to whom it will be communicated. The scope describes the most important methodological choices, assumptions, and limitations. It should be well defined sufficiently to ensure that the breadth, the depth and the detail of the study are sufficient and suitable to address the stated goal. This phase leads to the definition of a functional unit, system boundaries, system assumptions, system limitations, certain principles of allocation, and quality of data. The functional unit sets the scale for comparison of two or more products including improvement to one product (or system). All data collected in the inventory phase is to be related to the functional unit. Definition of the functional unit is of particular importance when different products fulfilling the same function are compared. The system boundaries define the processes/ operations (e.g. manufacturing, transportation, and waste management procedures), and the inputs and outputs of energy flow to be taken into account in the LCA. System assumptions describe handling of elementary features in calculations. System limitations are made towards nature, time frame, geographical area, capital goods, and other product lifecycles, which interact with the process. Allocation principles consider the output of several products from the same production system. Data of little influence on the final result need to be less accurate while dominating sources must be precisely defined (Forsberg et al. 2000).

The quality of the data used in the inventory is naturally reflected in the quality of the ultimate LCA. It is substantial that the data quality is described and assessed in a methodical way which allows others to comprehend and control the actual data quality. Initial data quality requirements aimed at, define the following parameters:

• Time-related coverage: the desired age (e.g. within last five years) and the minimum length of time (e.g. annual).
• Technology coverage: nature of the technology involved(e.g. weighted average of the actual process mix, best available technology or worst operating unit).
• Geographical coverage: the geographic area from which data for unit operations should be collected to satisfy the goal of the study (e.g. local, regional, national, continental, global).

5.2 Life cycle inventory analysis

Inventory analysis is the second phase of a life cycle analysis process. It is characterized by the assimilation of the data, and the modeling of energy flows for the product/process under the study. The data collected and used here includes all the environmental and technical quantities of all significant unit processes within the system boundaries (Handbook for Life Cycle Assessment 2009). The usage of energy, water and materials and their associated releases to the environment (e.g., air emissions, solid waste disposal, wastewater discharges) are identified and quantified (Curran et al. 2006).

5.3 Life cycle impact assessment

The loadings identified in the inventory analysis are characterized and assessed in this phase, based on their effects on the environment. Impact assessment consists of three consecutive elements: (1) classification, (2) characterization, (3) valuation. Classification is the step in which relevant impact categories, i.e. environmental problem areas, are identified, and the loadings are assigned to each impact category they contribute to. Appropriate impact category selection is crucial; examples: resource depletion (depletion of abiotic resources and depletion of biotic resources), pollution (global warming, ozone depletion, human toxicity, ecotoxicity, photochemical oxidant formation, acidification, eutrophication) and degradation of land ecosystems and landscape (land use). The characterization element assesses the contribution of all input/output data from the inventory to the respective category to finally obtain an impact profile for the product assessed. This is assisted by using models, that combine the input/output data from the inventory and the so-called indicator that expresses the environmental effects or harms. In general, the indicators allow for an aggregation of all emission-based contributions within each category, in terms of a unit. If appropriate, characterization factors are used to enumerate the contribution of each single emission to that category. An appropriate set of impact factors is applied for impact aggregation. Two primary categories of life cycle impact factors exist as mid-point and end-point. Mid-point assessment methods are more scientifically verifiable and use a set standard of impact category for a given inventory value, such as methane to carbon dioxide (CO2) equivalents (Bare et al., 2000). The use of end-point impacts strives to give an actual environmental or economic outcome to the emissions. Although end-point assessment methods are well formulated, they usually apply some assumptions that deviate from assessable outcomes, such as an increase in mean global temperature due to methane emissions. During this step, it is possible to precisely categorize (e.g., human health), spatially normalize (e.g., regionally or nationally), or weigh the impacts to determine a total LCA score. Use of these standardization techniques is noncompulsory and will depend on the goal of the particular study, and may incorporate additional uncertainty into the analysis. These come under the last stage of impact assessment, ‘valuation’ which attempts to compare and rank the differing impact categories to simplify them down to a common base (Barton et al.1996).

5.4 Interpretation

The last phase of LCA is ‘interpretation’. Here the results of the previous LCA phases are compared with the goal of the study set in the beginning. Validation is an important concern here. It can be done in two ways- (i) performance of sensitivity analysis by the LCA practitioners involved; and (ii) independent, external review (like a peer review). Also, there is the improvement assessment in which options for reducing the environmental impacts of the system under study are identified and estimated. This is executed on the basis of results from the previous LCA phases.

6. Advantages

There are basically four types of users of LCAs (Jensen, 1997):

*  Industry and other commercial enterprises;

*  NGOs (consumer organizations and environmental groups);

*  Government and regulatory bodies; and

* Consumers (which includes governments as consumers).

6.1 Industry and other commercial enterprises

LCA helps to understand the various environmental benefits and obligations that exist in the product or service that the industries produce. It also helps in communication of information when engaging with stakeholders (i.e. environmental organizations, involved communities, interested and affected parties and government authorities). The primary applications of LCA in the industry are in

i.  Product improvement – For product improvement, LCAs are done by manufacturers for creating a base reference from which new product can be developed or the required alterations to be made in manufacture of the product can be analyzed.

ii. Product designing – Fresh products are often developed from old designs and ideas, and LCA is a beneficial means of taking “old information” and relating it with plans and estimates for new product and services; this is known as product designing.

iii.    Formation of company policy – LCAs can contribute considerably to the development and formulation of Company Policy in specific areas, e.g. guidance on the choice of raw materials could directly affect a company’s approach to management of waste materials. In some cases, it could also result in a reduction in generation of harmful waste, with increased recycling potential.

iv.  Product information – Sometimes, government authorities need product information for the purposes of licensing or legal submission. Information obtained from LCAs can supply this requirement.

v. Use in negotiations – Information sourced from LCA can help to maintain a balance to ensure that, authority requirements are based on certified data and practicality. The outcomes can also be used to upkeep debates relating to the formulation of company policy “best practicable option”, and “best practicable environmental option” etc. when negotiating, for example, licenses, permits, and approvals.

NGOs

LCAs may make available valuable base data to NGOs on which to act and to motivate for change and improvement. If NGOs can negotiate with industry to make sure that core LCA data is freely accessible in the perspective of transparency and open corporate governance provisions, then communication of information on goods is less likely to generate complications.

Government and regulatory bodies

The government entities can utilize the information contained in the studies on sustainability issues, in the context of the economy and economic activities. The specific areas where government can use LCAs are

i.  Eco-labelling – Eco-labelling is granting recognition to products that achieve a certain minimum standard in “environmental friendliness”.

ii.  Deposit-refund schemes – Decision making on whether to introduce deposit-refund systems to encourage recycling and reuse of raw materials or not is a tough task. Detailed LCAs may facilitate an assessment to be made on the viability of deposit-refund systems.

iii.  Subsidies and Taxation – Then LCAs can provide information to inform decisions on the introduction of shifts in taxation or subsidies and can also demonstrate how, for example, the purchase and production of cleaner products can be stimulated through subsidies such as low-interest loans for manufacturing investments.

iv. General Policy making – General policy can be informed by detailed LCAs, particularly on issues such as whether dangerous goods should be transported by rail or road or how the promotion of differing energy sources can be encouraged, depending upon availability, strategic planning or market flexibilities.

Consumers

LCA information helps the consumers on the purchasing options based on whether it is environment-friendly or not. By providing buyers with the information to make good choices on price, running costs and pollution potential, national environmental protection goals and policies become easier to implement, and data can be used to demonstrate how changes and improvements can decrease pollution in the short and long term. Other advantages include:

• The “cradle to grave” methodology of LCA outspreads beyond the typical limits of EIA  practices.
• The use of diagrams to illustrate the flows, stages, and processes of LCA is a valuable cognitive tool for capacity building.
• LCA can identify and track environmental pollution moving between water, air, and soil efficiently.
• Use of scores, with reliable data sets and impact categories, aids to make useful comparisons between products and processes in a broader manner as compared to that achieved in Environmental Impact Assessments.

7.  Disadvantages

Some of the significant limitations of LCA include:

1. Data quality: In a manufacturer-sponsored analysis to compare a product/process with its alternatives, data collectors may get current data from the manufacturer, but for the alternative product, they might have to be dependent on secondary data from the literature. Hence, comparative studies by the secondary data will lack credibility.
2. Life cycle boundaries: Most studies do not consider the working environment. The working edges taken into consideration may not be same all the time which will lead to a discrepancy in the result.
3. Absence of a perceived need for LCA: A common lack of environmental awareness, a lack of drivers for chain management and responsibility have generated a hurdle to the expansion of LCA.
4. Scarcity of LCA expertise: There is a lack of knowledge for performing and understanding LCA studies in developing countries. Communication about LCA procedures and study outputs, particularly to policy makers is a problem.
5. Cost of LCA Studies: The high level of expert understanding required by complex LCAs, together with the need to procurement of data from commercial databases put forward high costs, this is combined further with the added costs of ISO necessities for review.
6. Access to High-Quality Data: Data quality and availability (particularly for developing countries) creates a major practical tailback in LCA studies.
7. Lack of user-friendly and widely recognized LCA methods: Methodological barriers in LCA are related to the lack of commonly agreed methods, and this appears not to be satisfactorily addressed through ISO standardization.