ISO (International Organization for Standardization) develops International Standards over almost the entire range of technology. Its membership comprises the national standards bodies of some 120 countries. ISO standards are market driven. They are developed by international consensus among experts drawn from the industrial, technical or business sectors which have expressed the need for a particular standard. These may be joined by experts from government, regulatory authorities, testing bodies, academia, consumer groups or other organisations with relevant knowledge, or which have expressed a direct interest in the standard under development. This process ensures widespread use of the published standard. Although voluntary, a certain percentage, mainly those concerned with health, safety or environmental aspects, has been adopted in some countries as part of their regulatory framework.