Conducting an LCA

To see the interrelatedness of the four components of an LCA, it is useful to refer to the flowchart shown in Figure 6.2.

Goal Definition and Scoping

The LCA process can be used to determine the potential environmental impacts from any product, process, or service. The goal definition and scoping phase will determine the time and resources needed. The defined goal and scope will guide the entire process to ensure that the most meaningful results are obtained. Every decision made during goal definition and scoping impacts either how the study will be conducted or the relevance of the final results. Goal definition and scoping will result in the determination of the following:

1. The goal(s) of the project
2. The type of information is needed to inform the decision‐makers
3. How the data should be organized and the results displayed
4. What will or will not be included in the LCA
5. The accuracy required of the data
6. Ground rules for performing the work

Each decision made in the fleshing out of these six areas has an impact on the LCA process, as explained in Sections 6.2.3.1 through 6.2.3.6.

Define the Goal(s) of the Project

The primary goal of the LCA is to choose the best product, process, or service with the least effect on human health and the environment. There may also be secondary goals for performing an LCA, which would vary depending on the type of project. Some typical secondary goals are as follows:

• To prove one product is environmentally superior to a competitive product
• To identify stages within the life cycle of a product or process where a reduction in resource use and emissions might be achieved
• To determine the impacts to particular stakeholders or affected parties
• To establish a baseline of information on a system’s overall resource use, energy consumption, and environmental loadings
• To help guide the development of new products, process, or activities toward a net reduction of resource requirements and emissions

Determine the Type of Information Needed to Inform the Decision‐Makers

LCA can help answer a number of important questions. Identifying the questions that the decision‐makers care about will help define the study parameters. Some examples include the following:

• What is the impact to particular interested parties and stakeholders?
• Which product or process causes the least environmental impact (quantifiably) overall or in each stage of its life cycle?
• How will changes to the current product/process affect the environmental impacts across all life cycle stages?
• Which technology or process causes the least amount of acid rain, smog formation, or damage to local trees (or any other impact category of concern)?
• How can the process be changed to reduce a specific environmental impact of concern (e.g. global warming)?

Once the appropriate questions have been identified, the types of information needed to answer them will be apparent.

Determine How the Data Should Be Organized and the Results Displayed

LCA practitioners like to organize data in terms of a functional unit that appropriately describes the function of the product/process being studied. Comparisons between products and processes must be made on the basis of the same function, quantified by the same functional unit. This ensures that the activities being compared are true substitutes for each other. Careful selection of the functional unit to measure and display the LCA results will improve the accuracy of the study and the usefulness of the results.

An LCA study comparing two types of wall insulation to determine environmental preferability must be evaluated on the same function, the ability to decrease heat flow. Six square feet of 4‐in. thick insulation Type A is not necessarily the same as 6 ft² of 4‐in. thick insulation Type B. Insulation type A may have an R factor equal to 10, whereas insulation type B may have an R factor equal to 20. Therefore, types A and B do not provide the same amount of insulation and cannot be compared on an equal basis. If Type A decreases heat flow by 80%, you must determine how thick Type B must be to also decrease heat flow by 80%.

What Will and Will not Be Included

Ideally, an LCA includes all four stages of a product or process life cycle: raw material acquisition, manufacturing, use/reuse/maintenance, and recycle/waste management. These product stages are explained in more detail in the following. To determine whether one or all of the stages should be included in the scope of the LCA, the following must be assessed: the goal of the study, the required accuracy of the results, and the available time and resources. Figure 6.3 presents a set of life cycle stages that could be included in a manufacturing project related to treatment technologies. Note the “system boundary,” which encompasses all aspects of the LCA. Additional examples of the four life cycle stages are explained in more detail in the following.

Raw Materials Acquisition 

The life cycle of a product begins with the removal of raw materials and energy sources from the Earth. For instance, the harvesting of trees or the mining of nonrenewable materials would be considered raw materials acquisition. Transportation of these materials from the point of acquisition to the point of processing is also included in this stage (USEPA 1993).

Manufacturing 

During the manufacturing stage, raw materials are transformed into a product or package, which is then delivered to the consumer. The manufacturing stage is broken into three parts: materials manufacture, product fabrication, and filling/packaging/distribution (USEPA 1993). While those activities are self‐explanatory, it is noted that distribution in which finished products are transported to retail outlets or directly to the consumer entails environmental effects due to mode of transportation trucking, shipping, or others.

Use/Reuse/Maintenance 

Once the product is in the consumer’s hand, all activities associated with the useful life of the item must be identified: energy demands and environmental wastes from product storage and consumption, as well as any reconditioning, repaired or servicing may be required (USEPA 2012). When the consumer no longer needs the product, it will be recycled or disposed of.

Recycle/Waste Management 

Disposition of any product or material whether by recycling, incinerating, dumping, or other mode of waste management requires energy and results in other environmental wastes (USEPA 1993, 2012). These must be anticipated and listed.