This paper both presents and discusses the results of calculations on the Cumulative Energy Demand (CED) and the related Cumulative CO2 emissions (CCO2) for products of the organic chemical industry. The entire process chain is studied, starting with the extraction of resources and ending with the saleable material (cradle-to-factory gate). The materials studied are chemical intermediates and plastics as produced in Germany in the mid 1990s. The two bulk plastics, polyethylene and polyvinyl chloride, belong to the group of polymers that can be produced with a relatively low input of energy resources. By contrast, the CED and the CCO2 values for manufacturing engineering and special plastics can be more than twice as high. The CED and CCO2 data determined on the basis of our calculations is compared with data from other sources. The differences show that for a reliable study it is essential that use is made of only one set of data which has been determined in a consistent manner. In contrast, comparative assessments which use CED and CCO2 data originating from various sources, can easily result in distorted conclusions given the large data ranges. The data ranges found indicate that considerable uncertainties continue to exist, calling for further analysis in the area. Comparative calculations using CED and CCO2 data from independent, consistent sources are recommended for the time being. (C) 2003 Published by Elsevier Science Ltd.