Six Factors that can make or break your Permit to Work System

bigstock-Redhead-man-with-long-beard-we-417108145The main HSE guidance on Permits to Work is the HSG250 ACOP Guidance on Permit-to-Work Systems. The HSE guide describes good practice in the use of permit-to-work systems, and will help operators using these systems to ensure risks have been reduced to a level as low as reasonably practicable. Although the document has specific emphasis for the chemical sector, the principles can be applied to any circumstance necessitating a permit to work system.

The guide makes an important point about the purpose of a permit-to-work – it is not simply permission to carry out a dangerous job, it must form part of a whole safe working system. 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. If you aren’t using the permit system correctly it is unlikely to provide the protection you want for your people or workplace. The HSE identifies the following essential factors which are part and parcel of an effective permit to work system.


Copies of a permit to work should be clearly displayed at the worksite, in a control room (if there is one) and with the permit issuer. If the permit isn’t clearly visible at the work site operating staff may not be aware equipment is under maintenance and not available for operation.

Suspension and Cancellation

You must have a clear system for dealing with active, suspended and cancelled permits. Occasionally a job may be temporarily halted, for example, if there’s a general alarm or a wait for spares. Suspended permits should be kept on the permit recording system with a record of the condition in which the plant has been left, there may still be active isolations under a suspended permit. The work should not be restarted until the issuing authority has verified that it is safe to do so, and has revalidated the permit

If the permit is cancelled, the suspended job is treated as if it were new work when it is restarted. This is preferred option if the suspension of work is indefinite and the plant is operationally safe.

Permit Interaction

There is always the potential that an activity under a permit-to-work will create danger for another, even if the other work does not require a permit-to-work. This is why your permit to work process should highlight any potential interaction and take account of other activity currently planned or underway. It may be that the interacting activities are covered by separate responsible authorities. For example, if a contractor is involved there should be an established system of communication on safety matters between the two companies on safety issues including cross referencing of active and planned permits to work.


If work is carried over to another shift, the handover procedure should ensure that the incoming shift is aware of any outstanding permit-controlled jobs, the status of those jobs, and the status of the plant. Work-in-progress should be left in a condition that can be reliably communicated to, and understood by, the oncoming shift.


There should be a clear hand-back procedure involving the people performing the work, issuing the permit and controlling operations. The process should confirm that the work has been completed and returned to a safe condition.


Permit authorisation and supervision

A permit-to-work system will not be fully effective if the permits aren’t being coordinated and controlled by an issuing or other responsible authority. This won't happen if there isn’t adequate supervision and monitoring of the system to make sure that the specified procedures are being followed.

This should include site visits, as a minimum, at start and completion of the task, with interim checks depending on hazard, complexity, and duration of task. If there’s a project requiring a large number of active permits, management should ensure that there is additional resource available where needed. Permit issuers need sufficient time to check site conditions and to ensure effective implementation, especially where high hazard or complex tasks are involved. Inadequate resourcing will damage the effectiveness of your permit to work system and overall site safety.

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