Life cycle assessments are the standard for quantifying environmental impacts. The first step in a complete assessment, as outlined in ISO 14040, is to complete the life cycle inventory, LCI. An LCI provides the quantitative information to proceed with an impact assessment. For example, with an LCI one can conduct the calculations to understand the emissions of greenhouse gases.
2009 Life Cycle Inventory of 100% Postconsumer HDPE and PET Recycled Resin from Postconsumer Containers and Packaging