Permit to Work Systems

What are Permits to work ?
A permit-to-work (PTW) system is a formal written system used to control certain types of work that are potentially hazardous. A PTW is a document, which specifies  the work to be done, and the precautions to be taken. Permits-to-work from an essential part of safe systems of work for many maintenance activities. They allow work to start only after safe procedures have been defined and they provide a clear record that all foreseeable hazards have been considered.
A permit is needed when maintenance work can only be carried out if normal safeguards are dropped or when new hazards are introduced by the work. Examples are entry into vessels, hot work and pipeline breaking.

Permit to Work (PTW)
Managers and supervisors must not assume that any existing system is a good one just because there has not yet been a serious accident. The work system should be critically reviewed to check the following points. If there is no system in place the following information gives guidance on how a PTW system should operate:
Information

• The permit-to-work system must be fully documented, laying down:

1. How the system works;
2. The jobs it is to be used for
3. The responsibilities and training of those involved; and
4. How to check its operation

• There must be clear identification of who may authorize particular jobs. Any limits to their authority must also be specified
• People responsible for specifying the necessary precaution (e.g. isolation, emergency arrangements, etc.) must be clearly identified
• The permit form has to be clearly laid out
• The permit form must avoid statements or questions which could be ambiguous or misleading
• The permit-to-work has to be designed to allow for use in unusual circumstances
• Contractors working on site must also be covered

Essentials of the permit to work form
The PTW form must help communication amongst everyone involved. The company issuing the permit should design it, taking into account individual site conditions and requirements. Separate permit forms may be required for different  tasks, such as hot work and entry into confined spaces, so that sufficient emphasis can be given to the particular hazards present and precaution required.