Life-cycle assessment in US codes and standards

Life-cycle assessment is a comprehensive method used to assess and quantify the environmental impact of a product or process over its entire life cycle. The most representative output of a product's environmental impact takes into account all environmental flows over the full life of the product. These environmental flows include material and energy resources that go into a product, as well as all emissions to air, water, and land. A life-cycle assessment over the full life cycle of a product-from extracting raw materials from nature, any transformation or manufacturing of these raw materials into a product, the product use, and end-of-life scenarios, such as recycling or disposal-is considered a cradle-to-grave study. This article defines life-cycle assessment and explains how it fits into U. S. codes and standards.