Research areas: The multiple meanings of concepts of work accidents and professional illnesses seen from the standpoints of risk prevention (the concept of risk) and Social Security (concept of contingency): convergences and dysfunctions;Assignation of social security liabilities related to work inspections in cases of non-compliance with safety measures: Temporary Employment Agencies Contractors and Subcontractors;Incapacity disability and handicaps and risk prevention at work;New social needs and the demands for reforms to the social security system;Susceptible subjects maternity benefits and risks during pregnancy and protection of maternity within the scope of employment;The two faces of work accident insurance companies;Liability in social security and prevention matters;Specific issues for self-employed workers;The STILL confusing nature of benefit surcharges;Preventive measures in the workplace maintenance of healthy conditions quality of life and protection of dependent persons under age 65;Implications for Social Security schemes for the self-employed (RETA RETM REA): obstacles to homogenization and schemes;Work accident rate and the protection of dependent persons under age 65;Compatibility and incompatibility of liabilities: Extension of the NON BIS IN IDEM principle;New pathologies (moral harassment brain and cardiovascular illnesses etc.);Commercial risk insurance and voluntary improvements;Partial retirement flexible retirement atypical work contracts and risk assessment;Protection of certain collectives.