Workshop 3: Psychosocial environment of work: definitions and tools to characterise it. There is no consensus on the classification of the dimensions of the psychosocial work environment. Over the last 35 years, researchers, experts and stakeholders working in occupational health, occupational sociology and psychology, industrial relations and management have proposed different ways of designing and characterising the psychosocial environment of work. These approaches vary according to country, discipline and context of research or intervention practice. Despite these disparities, there was an interest in discovering aspects of work organisation and the demands of psychological and interrelationship work that can influence the psychological condition of the person and/or have adverse effects on other health aspects such as cardiovascular health, and more recently MSDs. Several national occupational health researchers and institutes have proposed different ways to classify these risks and different conceptual models (Huang et al. 2002; Kristensen et al. 2005, Lindstrom et al. 2002). Tabanelli et al. (2008) identified 33 tools for measuring psychosocial factors at work (26 questionnaires and 7 observation tools) published in scientific literature. Recently, in France, the Minister for Labour has mandated a college of expertise to draw up proposals for statistical monitoring of psychosocial risks at work. In October 2009, this panel of expertise proposed a reference framework for psychosocial risks with 6 axes and identified a provisional set of existing indicators to measure different elements of these axes. The 6 proposed axes include: (1) requirements at work (e.g.: amount of work, time pressure, complexity of work, difficulties in reconciling work and personal life); (2) emotional requirements (e.g.: emotional exhaustion, relationship with the public, empathy and suffering, tensions with the public, having to hide emotions, fear at work); (3) autonomy and room for manoeuvre (e.g.: procedural autonomy, decision-making authority, use of powers); (4) social relations and relations at work (e.g.: social support for work, recognition, violence); (5) conflict of value; (6) job insecurity. The choice of psychosocial indicators depends on the objectives of the researcher or speaker and the elements of the work to be identified. It is also important to take into account the psychometric characteristics of the indicators: their validity, reproducibility and sensitivity to change. Does the tool measure the phenomenon that is intended to be precisely characterised? Does it have the capacity to collect the same results whenever the same phenomena manifest themselves in a similar context? Is it able to show an increase or decrease in the phenomenon studied when a real change took place? Therefore, users of indicators should know beforehand whether these characteristics have been studied and, if so, whether the chosen indicator is valid, reliable and change sensitive in the context of the intended use.