Book excerpt: This OECD Emission Scenario Document (ESD) provides information on the sources, use patterns, and release pathways of chemicals used in industrial cleaning. This document provides a method of estimating emission quantity in the absence of sufficient empirical data to support an analysis of the substitution of one industrial cleaner for another. Among scenarios that are highly likely to occur (as determined by analysing trends in the substitution of cleaning chemicals), possible combinations of currently used substances and their substitutes are focused. Changes in operating conditions and cleaning equipment due to the use of substitute materials are also examined.