Available production figures are rather diverse with respect to compound classes covered, inclusion or not so of intermediates, and geographical and temporal coverage. They are therefore difficult to compare, and some seem to be conflicting. The numbers given in the following nevertheless illustrate the order of magnitude and the dynamic increase of production and use of organosiloxanes. Taking into account the above uncertainties, these figures seem roughly consistent. Thus, the current annual worldwide production of organosiloxanes may reasonably be assumed to be several million tons. All of this material, after a shorter or longer time, will be released to the environment in one form or another. For example, silicones used in construction are conserved in a building for many years, to be released upon demolition, while other applications are based on shorter time scales.