Sometimes used as a synonym for risk coefficient. However, this is different from the normal medical use of the term risk factor to indicate a factor that influences an individual's risk, and therefore should be avoided
International Atomic Energy Agency IAEA, Department of Nuclear Safety and Security, IAEA Safety Glossary (Terminology Used In Nuclear Safety and Radiation Protection), IAEA, Vienna. Austria 2007. ISBN 92-0-100707-8, http://www-pub.iaea.org/MTCD/publications/PDF/Pub1 290_web.pdf, (Nucl Sfty and Rad Prot - Brit) {459}