Permit to Work

The Permit to Work (PTW) procedure is a well-proven method which predetermines the work to be done, analyses the hazards and controls that have to be implemented. The learning outcomes of the training provide an understanding of the benefits of PTW, the essential features of the system, the mechanics of implementing the system and monitoring its effectiveness.

1 )  The petroleum, chemical and allied industries store and process large quantities of hazardous substances including flammable and toxic materials, so the potential for serious incidents is clear. To prevent such incidents it is vital that there should be effective management of hazards, including the use of safe systems of work.

2)  A permit-to-work system is an integral part of a safe system of work and can help to properly manage the wide range of activities which can take place close together in a small space, such as in a storage area or process plant.

3)  When incidents do occur, human factors, such as failure to implement procedures properly, are often a cause. These failures may in turn be attributable to root causes such as a lack of training, instruction, communication or understanding of either the purpose or practical application of permit-to-work systems.

4)  Permit-to-work systems form an essential part of the task risk assessment process. When a task is identified an appraisal should be carried out to identify the nature of the task and its associated hazards. Next, the risks associated with the task should be identified together with the necessary controls and precautions to mitigate the risks. The extent of the controls required will depend on the level of risk associated with the task and may include the need for a permit-to-work.

5)  A permit-to-work is not simply permission to carry out a dangerous job. It is an essential part of a system which determines how that job can be carried out safely, and helps communicate this to those doing the job. It should not be regarded as an easy way to eliminate hazard or reduce risk. 

The issue of a permit does not, by itself, make a job safe – that can only be achieved by those preparing for the work, those supervising the work and those carrying it out. In addition to the permit-to-work system, other precautions may need to be taken – eg process or electrical isolation, or access barriers – and these will need to be identified in task risk assessments before any work is undertaken.

The permit-to-work system should ensure that authorized and competent people have thought about foreseeable risks and that such risks are avoided by using suitable precautions. Those carrying out the job should think about and understand what they are doing to carry out their work safely, and take the necessary precautions for which they have been trained and made responsible.