Life Cycle Assessments

A life cycle assessment (LCA) is a systematic gate-to-gate, cradle-to-gate, and cradle-to-grave process that evaluates the environmental impacts of products, processes, and services.

Its quality depends on the life cycle inventory data it uses.

"In principle, all decisions that affect or are meant to improve the environmental performance of a product/service should be scrutinized in terms of their life cycle implications. For the environmental perspective, a product's life cycle can be represented as a circular movement that ties together resource extraction, production, distribution, consumption and disposal. In other words, all the phases of organized matter and energy that are in some way related to the making and use of a product can also be linked to an impact on the environment."

—Organization for Economic Cooperation and Development,
Paris, France, 1995

An LCA tracks a product's environmental impact from resource extraction through disposal and examines both the energy it uses and the pollution it creates. The data are first analyzed in the context of the inventory involved, and then are joined with an assessment of both goals and potential impacts. From this point, the next data interpretation step evaluates the processes and impact indicators to determine how to reduce environmental burdens. LCAs benefit manufacturers, architects, builders, and government agencies by answering environmental impact questions and identifying areas for improvement.

Many in industry and government are using LCAs, but they may be cautious about using the results in a public forum because they could expose proprietary or sensitive information. Our USLCI Database Project solves this problem by creating a central resource for reliable life cycle inventory data that are supported by a credible agency that can be used by everyone without exposing sensitive information.

Interest in LCAs is growing internationally. Many countries understand the importance of using LCAs to identify and evaluate opportunities to minimize resource consumption and air, water, and land pollution.

Environmentally Friendly Shirts

A project in the Netherlands included an LCA for a man's shirt. The retailer who participated in this project was interested in developing an environmentally friendly range of shirts. The main questions asked were:

  • Which phase in a shirt's life cycle produces the most pollution?
  • Are natural or synthetic fibers environmentally preferable?

The environmental impacts of the shirts occurred during four phases:

  1. Production (cotton growing, spinning and weaving, dyeing and finishing)
  2. Transportation
  3. Use (washing, drying, and ironing)
  4. Disposal (reuse, recycling, composting, and incinerating).

The results showed that most of the environmental impact occurs during transportation to the retail outlet and during the use phase. For example, washing the shirts at 140°F (60°C) uses twice as much energy as washing them at 104°F (40°C). Synthetic or mixed textile fibers are environmentally preferable because they are easier to dry and iron, which further reduces energy consumption.

Environmental Benefits

Reduction in energy use         10%
Reduction in detergent use   >20%

Economic Benefits

Consumers reduce energy costs by 10% and detergent costs by 20%.

Adapted from Life Cycle Assessment: What It Is and How to Do It, United Nations Environment Programme Industry and Environment, Paris, France, 1996, p. 23.