SOURCE REDUCTION
This chapter describes the development of material‐specific emission factors for source
reduction in EPA’s Waste Reduction Model (WARM). Source reduction, or waste prevention, refers to
practices that reduce the amount of materials entering the waste stream, including changes in the
design, manufacture, purchase or use of materials. This document provides examples of source
reduction and a summary of how EPA estimates the GHG benefits from source reduction of materials.
1 TYPES OF SOURCE REDUCTION
Source reduction can result from any activity that reduces the amount of a material needed and
therefore used to make products. Some specific examples of source reduction practices are:
• Redesigning products to use fewer materials (e.g., lightweighting, material substitution).
• Reusing products and materials (e.g., a refillable water bottle).
• Extending the useful lifespan of products.
• Avoiding using materials in the first place (e.g., reducing junk mail).
In addition to the activities above, there are limited circumstances where the emission factors
can be used to estimate GHG benefits of substituting one material or product for another material or
product. Section 3.2 presents considerations for estimating the GHG effects of material substitution.