This report contains guidance material for Human Factors (HF) studies within the various forms of risk and error assessment and analysis. It defines the terminology used in such studies, and includes information on applicable legislation, guidelines and standards; process descriptions and techniques. In Safety, Health and Environment, Human Factors (also called ergonomics) is concerned with "environmental, organisational and job factors, and human and individual characteristics, which influence behaviour at work in a way which can affect health and safety” ?[1]. As a multidisciplinary field involving psychology, physiology, and engineering, among other disciplines, Human Factors is a broad subject. It is involved in the design, development, operation and maintenance of systems in all industrial sectors. This datasheet aims to provide the user with a greater awareness of Human Factors theory and practice