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LCA

Definition and objectives
Methodology
Applications
Strenghts and limitations
Educational tools

Definition and objectives

The International Organization for Standardization (ISO) defines life cycle assessment (LCA) as the following:

"Compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product system throughout its life cycle" (ISO 14040: 1997)[1].

Among the tools that life cycle management (LCM) offers, LCA, or environmental balance, is one of the most comprehensive and high-performance methods. LCA is the only method that assesses the environmental impacts of a product or activity (a system of products) over its entire life cycle. It is therefore a holistic approach that takes into account:

  • Extraction and treatment of raw materials
  • Educational tools
  • Product manufacturing
  • Transport and distribution
  • Product use
  • End of life.

The main goal of the method is to lessen the environmental impacts of products and services by guiding the decision-making process. For companies, designers, and governments, LCA represents a decision-making aid tool for implementing sustainable development.

Methodology

Regulated by the ISO 14040 series[2] standards, LCA consists in four distinct phases:

  1. Goal and scope definition (study model which defines the methodological framework which all other LCA phases must comply with)
  2. Inventory of all the inputs and outputs related to the product system
  3. Assessment of the potential impacts associated with these inputs and outputs
  4. Interpretation of the inventory data and impact assessment results related to the goal and scope of the study.

The following figure illustrates the LCA framework as described by ISO. As shown in the figure, LCA is an iterative process. The choices made during the course of the study can be modified following new information.

 

LCA framework according to ISO

Due to time and cost constraints, variants of the LCA method have been formulated according to the guideline principles established by the Society of Environmental Toxicology and Chemistry (SETAC). For example, the boundaries of a system can be limited to certain life cycle stages or to certain impact categories or limited to the main contributors, identified according to expert opinion and experience.

The analysis can also be performed in a strictly qualitative fashion or using « secondary » data only (generic data from the literature or from databases). Such simplifications can affect the accuracy and applicability of LCA results, but can nevertheless allow for the identification of potential impacts and, to a certain extent, their assessment.

Applications

LCA has become an important tool for the environmental impact assessment of products and materials and businesses are increasingly relying on it for their decision-making. The information obtained from an LCA can also influence environmental policies and regulations.

In practice, LCAs are mainly used for (Labouze et al., 1996):

  1. Environmental systems comparison

    LCA is used for comparing on an environmental basis:
    • various types of similar products for granting eco-labels
    • life cycle stages to enhance the environmental value of a product
    • processes or services for conformity analyses
    • production methods
    • product and process choices.
  2. Manufacturing (as a improvement lever for the manufacturing phase)

    LCA can be employed with the aim of finding the most ecological way to improve product manufacturing. Consequently, it can be useful as a decision-making tool for new product development, as a guide for the optimization of energy and raw material consumption as well as for the identification of solutions in emission reduction and possible substitution of harmful substances.
  1. Commercial development

    LCA can also be used for commercial development:
    • for obtaining authorizations (in the case of a new product for example)
    • for marketing (in the case of a certification or the creation of a marketing image)
    • as an aid for informing the public (within the framework of an environmental product declaration (EPD), for example).

A significant number of LCA studies, European for the most part, have already been conducted on several different subjects. The following list is not exhaustive:

  • Clothing
  • Grocery bags
  • Packaging and containers
  • Vending machines
  • Edible products
  • Personal computer
  • Diapers
  • Paper
  • Buildings
  • Cars
  • Bottles
  • Pharmaceutical products
  • Sanitary landfill
  • Contaminated sites
  • Means of transport
  • Hotel services
  • Doors and windows
  • Electric household appliances.

Strenghts and limitations

Strenghts

Life cycle assessment (LCA) is a tool which offers many advantages:

  • LCA is the only tool that examines the environmental impacts of a product or service throughout its life cycle
  • LCA is an ISO standardized method
  • LCA provides a comprehensive overview of a product or service and avoids simply shifting the source of the pollution from one life cycle stage to another
  • LCA can, for example, guide a company's decision-making process (micro-economic level) and help governments define a public policy (macro-economic level)
  • LCA challenges preconceived notions by distinguishing between the information that is relevant for objective quantification and the issues that pertain to policies, priorities, and social choices.

Limitations

LCA has however certain limitations:

  • The results of an LCA are geographically dependent. Hence, the results of an LCA carried out in Europe cannot be applied to Quebec without taking into account the significant variations related to the geographical context (for example, Québec relies on hydroelectricity while Europe emplys other sources of energy such as nuclear)
  • LCA only assesses potential impacts and not real impacts. Hence, it does not provide any information on the consequences of not following regulations or on environmental risks
  • The results of two LCAs on a same subject may differ according to the objectives, processes, quality of the data, and the impact assessment methods used. This is why ISO insists on transparency in LCA
  • A detailed LCA requires inventory data of all of the elementary processes included within the parameters of the system. Databases, LCA software, and even human resources are required to analyze all the data.

Educational tools

Introduction to Life Cycle Assessment (LCA)

For more information about LCA

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[1] ISO 14040:1997, Environmental Management: Life Cycle Assessment– Principles and framework, International Organisation for Standardization.

[2] ISO 14040:1997, Goal and Scope; ISO14041 (1998), Life Cycle Inventory Analysis; ISO14042 (2000), Life Cycle Impact Assessment; ISO14043 (2000), Life Cycle Interpretation; ISO14048 (2002), Environmental Management: Life Cycle Assessment – Data documentation format, International Organization for Standardization.