Isolation of energies: Establishing Safe Working Conditions

Work on a machine or a manufacturing process subjects operators to many risks mostly due to presence of multiple sources of energy (electrical, mechanical, hydraulic, pneumatic, etc.). The paper entitled “Operating on machinery out of production modes: principles and accidentology” presented at the 2010 SIAS conference highlighted recurrent issues affecting lockout procedures, isolation and operating live (i.e. under energy). Ensuring safe energised working conditions requires us to consider not only technical but also organisational and operational factors. A first approach to the technical aspects of isolation involving electrical, mechanical and fluid energies has been provided in a dedicated booklet. This paper introduces this document, which describes and explains both lockout devices and an exhaustive operation lockout-to-restoration procedure. The paper subsequently addresses isolation application and applicability based on operator knowledge and risk perception. These aspects have been considered in relation to electrical power, leading to establishment of task organisation and worker training principles. The situation is quite different for other forms of energy and common practices have not yet been adopted in this respect. Finally, we present fresh research involving indirect observation of isolation procedures by means of a questionnaire and interviews; this work may prompt publication of a series of good practices.